Audi A8 (type 4N) Self Study Programme 662
For internal use only.
Audi Service Training
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Launched in 1994, the Audi A8 was the world's first large-volume production car with a self-supporting aluminium body. Since then, Audi has built around a million cars with the Audi Space Frame (ASF) body. Its successor, the A8 (type 4N), continues this tradition. The design of the new A8 perfectly embodies the fundamental qualities for which Audi is renowned – sports appeal, lightweight construction and quattro all-wheel drive. Stylistically, the Audi A8 marks the beginning of a new design era for the entire brand. The front end with its wide, upright Singleframe grille and the fluid, muscular body symbolise sporty elegance, sophistication and progressiveness. The defining design feature of the new Audi A8 is spacious luxury; the cabin of the Audi A8 resembles a spacious lounge with generous proportions.
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In comparison with the predecessor model, both body variants are noticeably longer. The interior of the luxury saloon is deliberately minimalist, with a clearly defined and strictly horizontal architecture. Audi carries its high quality standards into the digital age with a radically new operating concept. The driver controls the infotainment system with fingertip control on the large display. The driver can use a second touchscreen display on the centre tunnel console to access the air conditioning and comfort functions as well as making text inputs. The MHEV (mild hybrid electric vehicle) technology of Audi is based on the newly developed 48 volt electrical system – it supplies the 12 volt system, which in this case becomes the electrical subsystem.
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Learning objectives of this self study programme: This self study programme describes the design and function of the Audi A8 (type 4N). Once you have completed this self study programme you will be able to answer questions on the following topics:
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Engines available at launch 48 volt electrical system New suspension features New power transmission features New features of the assistance systems
Contents Introduction Presentation _________________________________________________________________________________________________________________________________________________4 Dimensions __________________________________________________________________________________________________________________________________________________6
Body Introduction _________________________________________________________________________________________________________________________________________________8 Attachments ________________________________________________________________________________________________________________________________________________12 Interior equipment ________________________________________________________________________________________________________________________________________14 Roof variants _______________________________________________________________________________________________________________________________________________19
Engines Petrol engine - diesel engine ______________________________________________________________________________________________________________________________20 Engine/gearbox combinations ____________________________________________________________________________________________________________________________21 Fuel tank ____________________________________________________________________________________________________________________________________________________22 SCR system (selective catalytic reduction) ______________________________________________________________________________________________________________24 Exhaust system for the 3.0l TFSI engine ________________________________________________________________________________________________________________26 Exhaust system for the 3.0l TFSI engine ________________________________________________________________________________________________________________27
Power transmission Overview ____________________________________________________________________________________________________________________________________________________30 Automatic gearbox selector mechanism ________________________________________________________________________________________________________________32 Parking lock emergency release __________________________________________________________________________________________________________________________33 8-speed automatic gearbox 0D5 _________________________________________________________________________________________________________________________34 Functions influencing the gearbox and sport differential _____________________________________________________________________________________________41
Suspension Overview ____________________________________________________________________________________________________________________________________________________44 Axles and wheel alignment _______________________________________________________________________________________________________________________________45 Adaptive air suspension (aas) _____________________________________________ ________________________________________________________________________________46 Steering system ____________________________________________________________________________________________________________________________________________47 Suspension __________________________________________________________________________________________________________________________________________________48 Wheels and tyres ___________________________________________________________________________________________________________________________________________49
Electrics and electronics Installation locations of the control units _______________________________________________________________________________________________________________51
Air conditioning Introduction of the new R744 refrigerant _______________________________________________________________________________________________________________52 New features of the Audi A8 ______________________________________________________________________________________________________________________________53
Safety and driver assistance systems Passive safety _______________________________________________________________________________________________________________________________________________54 Active safety ________________________________________________________________________________________________________________________________________________74 Driver assistance systems _________________________________________________________________________________________________________________________________98
Infotainment and Audi connect Overview of versions _____________________________________________________________________________________________________________________________________ 102
Inspection and maintenance Overview __________________________________________________________________________________________________________________________________________________104 Special tools and workshop equipment ________________________________________________________________________________________________________________106
Appendix Self study programmes __________________________________________________________________________________________________________________________________ 107
The self study programme teaches a basic understanding of the design and mode of operation of new models, Note new automotive components or new technologies. It is not a repair manual! Figures are given for explanatory purposes only and refer to the data valid at the time of preparation of the SSP. This content is not updated. Reference For further information about maintenance and repair work, always refer to the current technical literature.
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Contents
Introduction Presentation Audi has reneegineered the 4th generation A8 (type 4N) from the ground up. Thanks to a trendsetting design, state-of-the-art suspension solutions, touchscreen operating concept and superla-
tive comfort, the luxury saloon demonstrates Vorsprung durch Technik right across the board. Below you will find summarised the key features of the Audi A8.
Engines
3.0l V6 TDI engine with mono turbocharger > Max. power: 210 kW (286 hp) > Max. torque: 600 Nm
3.0l V6 TFSI engine with mono turbocharger > Max. power: 250 kW (340 hp) > Max. torque: 500 Nm The Audi A8 (type 4N) is the first Audi to come as standard with an electrified driveline. For this purpose, the engines are equipped with a mildhybrid system.
Displays and operation A new operating and display concept incorporating MMI touch response technology with 2 touchscreens, a switch panel (optional) and an illuminated button module with tactile and audible freeback, intelligent handwriting entry with whole-word and multifinger recognition. An Audi virtual cockpit with full HD resolution and optional head-up display.
Driver assistance systems For the first time, a central driver assistance control unit (zFAS) utilises the data generated by the sensors to comprehensively map the area around the vehicle. This map is updated continuously and used by a number of assistance functions. For example, adaptive cruise assist is a new driver assistance system, which is offered for the first time in the Audi A8 (type 4N) as optional equipment. It combines three formerly independent systems - adaptive cruise control, Audi active lane assist with "early" corrective steering point and traffic jam assist - in a single driver assist system. Intersection assist helps the driver in situations in which cross traffic ahead of the vehicle can only be seen late due to impaired visibility.
Suspension The front and rear axles have a precision five-link construction (dynamic allwheel-drive steering is optional). A sport differential is available as an option for even more dynamic handling. The adaptive air suspension has hydraulically controlled dampers which are adjustable to 4 height levels. A fully active Audi A1 active suspension is optional. It controls each wheel separately and allows a wide spread between c omfort and sportiness.
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Air conditioning
Body
A further, new refrigerant is used in the Audi A8 (type 4N): carbon dioxide. It has the chemical formula CO 2 and is also known as R744. It contains neither fluorine nor chlorine and is produced in a series of natural processes without depleting the earth's ozone layer.
The body of the Audi A8 (type 4N) follows the Audi Space Frame (ASF) principle. It is assembled from aluminium parts – the classic composite of cast nodal joints, extruded profiles and sheet metal. The occupant cell is made from hot-formed steel components, complemented by an ultra-highstrength, torsionally rigid rear bulkhead made from carbon-fibre composite (CFC). A magnesium dome strut completes the lightweight construction concept.
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Power transmission
Electrical system
8-speed automatic gearbox 0D5 has been redesigned and improved for the Audi A8. The use of an auxiliary hydraulic pump allows the internal combustion to be shut off under coasting in certain situations. This saves fuel. The rear final drive 0G2 is used on the rear axle. The "quattro with sport differential" drive system with sport differential 0D3 is optional.
The MHEV technology of Audi is based on the newly developed 48 volt electrical system – it supplies the 12 volt electrical system, which in this case is the electrical subsystem. The 48-volt electrical system is powered by a belt alternator starter (BAS) which is connected to the engine belt drive. A lithium-ion battery, which is positioned safely under the luggage compartment floor, serves as an energy storage device.
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Dimensions
) 3 7 4 1 ( 8 8 4 1
1049
1644
1633
1945
2130
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1
0 1
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)
9 9
1 5
5
7 9 6
989
3128
1185
5302 Illustration shows Audi A8 L
) 1
1
8 4 0
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3 8 9
7 9 6
989
2998
1185
5172 Illustration shows Audi A8 662_071
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) 2
1 8 5 1
) 3
) 2
2 0 5 1
3 5 5 1
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) 3
2 6 4 1
1159 0 4 8
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Exterior dimensions and weights
Inner dimensions and other specifications
Length in mm
5302 (5172)
Front cabin width in mm
15812)
Width (not including exterior mirrors) in mm
1945
Front shoulder width in mm
15023)
Rear cabin width in mm
15532)
Width (including exterior mirrors) in mm
2130
Rear shoulder width in mm
14623)
Height in mm
1488 (1473)
Load sill height in mm
697
Front track width in mm
1644
505
Rear track width in mm
1633
Luggage compartment capacity in l
3128 (2998)
Drag coecient cw
0.27
Wheelbase in mm
Capacity of fuel tank in l
72/824)
Unladen weight in kg
1945 (1920)
Max. gross weight in kg
2745 (2680)
1)
Maximum headroom Elbow room width 3) Shoulder room width 4) Optional The values given in brackets apply to standard wheelbase models. 2)
All dimensions are given in millimetres and refer to the unladen weight of the vehicle.
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Body Introduction The new Audi A8 (type 4N) is based on an advanced ASF body structure which, for the first time, is composed of different materials. With a mix of aluminium, steel, magnesium and carbon fibre reinforced polymer (CFRP), the load-bearing structure combines four different lightweight materials. However, the largest proportion (58%) is represented by aluminium components which, as cast nodal plates, extruded sections and sheet metal panels, are the characterisic elements of an ASF construction system.
A rear bulkhead made of carbon fibre saves around 50% compared with its predecessor and helps to make the body rigid and strong in spite of the lightweight design. The intelligent material mix is completed by a dome strut which is 28% lighter and made of magnesium A comparison with the topic of torsional rigidity shows that the value has been improved by up to 24% compared with the predecessor.
Key: Sheet aluminium Die-cast aluminium Aluminium section Ultra-high-strength steel (hot-stamped) Carbon fibre reinforced polymer (CFRP) Magnesium Advanced high-strength steel High-strength steel
Soft steel
Note The depicted image shows an Audi A8 with a standard wheelbase. The body of the long-wheelbase version (A8 L) is 130 mm longer in the vicinity of the B post and heel board. 8
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Connection system The following connection systems are used when assembling the multi-material body: (Information refers to the Audi A8 body structure with the standard wheelbase without attachments). > > > >
Resistance spot welds on steel (1802 pcs.) Resistance spot welds on aluminium (20 pics.) MAG welds (total seam length: approx. 970 mm) Laser welds on aluminium (total seam length: approx. 4755 mm) > MIG welds (total seam length: approx. 5552 mm) > Friction element welds (242 pcs.)
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Semi-tubular punch rivets (2583 pcs.) Pop rivets (74 pcs.) Flow drill screws (931 pcs.) Clinch connections (82 pcs.) Seaming (total seam length: a pprox. 15243 mm) Bonding (total seam length: approx. 112014 mm)
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Safety cell The occupant cell, also called the safety cell, is made of aluminium and conventional hot-formed steel. The occupant cell comprises the lower area of the end wall, the side sills, the B posts and the front area of the roof arch. Some of these sheet metal blanks are
produced with different thicknesses using tailored technologies and are also partially tempered if necessary. This reduces the weight and increases the strength especially in extremely safetycritical areas.
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B post The B posts are adapted specially to the areas of body rigidity and crash requirements, and are produced using tailor rolled blank technology. These are flexibly rolled blanks, where variations in sheet-metal thickness are produced by controlled opening and closing of the gap between the rollers. These variations in sheetmetal thickness not only save weight, but also create defined crumple zones which provide protection in the event side-on impact. The sheet metal thicknesses vary between 1.5 mm and 2.0 mm.
Partial tempering: The individual zones of the B post are cooled in the mould at different rates during hot working, giving them different strength characteristics. In a side-on impact the bottom section of the B post deforms in order to absorb energy. On the other hand, less deformation takes place in the upper section of the B post (at head height).
Ultra-high-strength
High-strength
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Roll hemming In the new Audi A8 (type 4N) roll hemming is used all around for the entire front and rear door sills. Passengers can therefore enter and leave the vehicles more easily and the driver's field of vision in the safety-related area of the A post can be enlarged. Improvements of up to 36 millimetres are therefore attained compared with the predecessor model.
Roll hemming is complemented by grip punch riveting, which fixes the side wall frame in its position, and supported by the all-round structural bonding. Only by developing and adapting these joining technologies is it possible to use the material concept in the A8 (type 4N) and combine the aluminium side wall frame with the hot-worked, ultra high strength sheet steel on the B post, roof arch and sill with the narrow flanges.
Roll hemming
Grip punch rivet
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B post
Carbon fibre rear bulkhead An ultra high strength, torsion-resistant rear bulkhead made of carbon fibre is the largest component of the occupant cell in the new Audi A8 (type 4N) and accounts for 33 per cent of the torsional rigidity of the overall vehicle. In order to fully absorb the
The carbon fibre rear bulkhead, which contains all fittings such as the loudspeakers, the rear louvre, the 3-point belts and the centre armrest, is inserted into the body through the rear window cutout during final assembly by means of a handling device and is con-
loads infibre the longitudinal or transverse and for shear forces, 6 to 19 layers are placed on top ofdirection one another load optimisation. These individual fibre layers are composed of 50-mm-wide bands which can be positioned individually at any fibre angle and with a minimum fibre cut to create a finished layer package.
nected toand the rivets. body structure using two-component strengthpreadhesive The two-component strength adhesive vents contact corrosion while a connection is created with the adjacent body components in conjunction with the manually affixed rivets.
Load application direction
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Attachments Fully electric door lock Another new feature of the A8 (type 4N) is the actuation of the door locks. A so-called e-lock is used in which the opening signal is transmitted electrically from the door inner handle or door outer handle to the door control unit via a microswitch. The door control unit in turn controls an electric motor which releases the rotary
latch, with the result that the lock opens. The microswitch for the door outer handle is located in the support arm. It moves after a few millimetres pressure on the door outer handle, the door control unit triggers the electric motor in the e-lock and the door can be opened with very little energy.
Exterior door handle switch driver side F546 front pass. side F547 rear driver side F548 rear pass. side F549
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Door handle, support arm and door lock in the rest state.
Emergency release mechanism In order to still be able to open the doors if, for example, the microswitch or the servo motor fails, 2 Bowden cables – 1 from the interior door handle and 1 from the outer door handle – to the door lock are available as before and form a mechanical connection as a fallback level. However, in order to be able to open the door mechanically, the interior door handle must be pulled far beyond the normal angle. The door can only be opened using the outer door handle after the locking cylinder or the interior door handle, for example, was first actuated. The outer door handle can then be pulled further than during normal actuation and with more energy.
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Normal exterior door operation via the microswitch.
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In t e r i o r d o o r o p e ra t i o n v i a a B o w d e n c a b l e
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E x te r i o r d o o r o p e r a t i o n v i a a B o w d e n c a b le
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Door opening via the microswitch The microswitch for opening the door is located in the interior door handle. In this case, too, a brief pull on the interior door handle is
sufficient. When the door control unit detects the switch being opened, it triggers the servo motor in the door lock.
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Interior door handle in the rest state Interior door handle switch Driver side F550 Front pass. side F551 Rear driver side F552 Rear pass. side F553
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Normal exterior door operation via the microswitch.
In certain situations, e.g. when a vehicle is detected within the danger zone by the exit warning system, the e-lock can also delay
the opening of the door to be in a position to give both visual and tactile warnings for a very short period of time.
Power latching The Audi A8 (type 4N) can also again be fitted with an electric
and unwinds the Bowden cable for the power latching system, but
power latching system for the doors as an optional extra. The drives units here are new - motors for the power latching systems V302, V303, V541 und V542, each of which no longer winds up
exerts pull via an integrated linear drive and thereby moves the rotary latch in the door lock to the end position.
Note Before disconnecing the 12 Volt battery, make sure that one door glass, for example, is open or that the ignition key is not inside the vehicle or in the luggage compartment.
Reference You can find further information on the electric door lock in Self Study Programme 664, "Audi A8 (type 4N) - Electrics & electronics". 13
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Interior equipment Dash panel A new operating concept not only in the MMI, but also, for example, when actuating the light switch or the air vents of the air conditioning systems also produced an entirely new design language in the interior of the Audi A8 (type 4N). Elegantly paired with Audi's well-known quality, innovative solutions combined with a new yet timeless design also create a completely new layout. The upper trims for the dash panel are available as desired with wood veneer or piano lacquer and form the wrap-around – the large arc which runs above the door trim panels as far as the rear. This area contains the air vents which are covered by these trims in the rest state. When air from the automatic air conditioning system flows directly into the interior, the shutters glide away upwards electrically while the air outlets move back a few centimetres, i.e. towards the driver and the front passenger. 662_109
Design Situated to the right and left of the central 10.1" touchscreen and around the light switch, covers with the same black panel appearance as the display itself create an uninterupted area. The transition between this level and the level of the air vents is in turn
covered on the right and left by a trim strip. This modular design must always be considered when performing dismantling work in the area of the dash panel. In this case please always refer to the instructions in the service literature.
Dash panel vent
Upper trim for dash panel
Trim strip
Cover in black panel design Dash panel vent Upper trim for dash panel Trim strip Cover in black panel design 10.1" touchscreen, display unit for front information display and operating unit control unit J685
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Front centre console: The black panel appearance of the dash panel is continued to the centre console. The transition is made through a second, 8.6" touchscreen with an operator control module at the bottom.
It is optionally available as a continuous touchscreen area integrated in the display optics.
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Design Thanks to the new design of the centre consoles at the front and back, their layout has also been revised. The modular design and therefore the latest repair instructions in ELSA must also be observed during dismantling and assembly work. The illustrations
8.6" touchscreen, display unit 2 for front information display and operating unit control unit J1060
published here show optional equipment or special features according to the specific country and may therefore also differ from equipment on your market.
Switch module in the centre of dash panel EX22 Centre console switch module 1 EX23
Selector mechanism
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Rear centre console Both Audi A8 body variants – with standard wheelbase and long wheelbase - are equipped as standard with a 3-seat system at the front, if required with a load-through hatch or a refrigerator box. In the Audi A8 L there is also an individual seat system, then without a non-folding centre armrest in the rear backrest, but with a long, continuous centre console. It contains an armrest, large storage compartments and, if required, folding tables, a 230 Volt socket, a drinks holder, the Audi phone box, an SIM and SD card reader and USB connections. Irrespective of whether the long, continuous centre console or the folding centre armrest is fitted in the rear backrest, the Audi A8 (type 4N) can be ideally equipped with the Rear Seat Remote operating concept for passengers sitting in the back. The Rear Seat Remote unit with its 5.7" OLED display is roughly as big as a smartphone and is housed in the centre armrest where it can be removed. The Rear Seat Remote unit can be used to set convenience and infotainment functions in the rear, e.g. seat positions, interior lights, louvres or the air conditioning system for the rear. Another option are heated armrests in the centre armrests at the front and rear, and in the doors. 662_113
Mounting and charging cradle for Smart Remote Control
Buttons for seat adjustment
Folding tables
Smart Remote Control, wireless operating unit 1 E859
Audi phone box
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Reference You can find further information on the Rear Seat Remote unit in Self Study Programmes 665 "Audi A8 (type 4N) "New air conditioning features and introduction of refrigerant R744" and 666 "Audi A8 (type 4N) Infotainment". 16
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Seats The seats in the Audi A8 (type 4N) have also been redesigned from scratch. The front seats are up to 4 kg lighter than in the predeces-
sor model, and glass fibre reinforced plastic (GFRP) is used in the rear seats.
Front seats The front seats are available in several designs. The top version is the comfort individual contour seat. In addition to pneumatic seat and backrest bolster adjustment, it also features as an option heating and ventilation, each separately controllable in 3 stages. The optional massage functions has also been extended.
Every backrest contains 16 small bubble-shaped air pockets, 3 above each other. They massage the entire back. For this purpose, there is a choice of 7 programmes and 3 levels of intensity. A small compressor for each seat delivers up to 0.5 bar pressure.
Individual contour seat
Standard seat
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Valve block 2 in driver seat N476
Massage mat
Compressor for multi-contour seat in driver seat V439
Backrest bolster adjustment
Valve block 1 in driver seat N475
Air cushion for lumbar support
Seat bolster adjustment
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Rear seat With the rear 3-seat system, the outer seats can be heated as an option. The longitudinal position and the seat and backrest angle can also be adjusted electrically. The lumbar support can then be adjusted pneumatically. If desired, a massage function is also
available here with 18 triple air pockets per seat. The individual seat system in the Audi A8 L also features the same adjustment options as those in the rear 3-seat system.
Reclining seat The first-class solution in the Audi A8 (type 4N) is the rear right reclining seat. Its user can move it to a reclined position and place his/her feet on an electrically folding area on the backrest of the special passenger seat. If required, the feet are warmed and massaged there in several stages. 3 intensities, 2 programmes and 3 foot sizes are available for this purpose. The entire foot reflex zones are also stimulated. The rear passengers can lean their head
on the soft comfort head restraints in the new Kokon leather version whose height here can be adjusted electrically. The reclining seat package features the comfort individual contour seats with ventilation and massage, the long centre console with a double folding table, the Rear Seat Remote operating unit, rear seat entainment and four-zone deluxe automatic air conditioning.
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Foot massage
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Rear Seat Remote
Massage, back area
Massage, shoulder area
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Roof variants Standard wheelbase Depending on body type, there are 2 optional versions of the panoramic glass sunroof. The A8 with a standard wheelbase has a single-piece glass roof with 2 drain hoses at the rear. These drain
hoses will prevent ice from forming on the roof during low temperatures, which in turn could produce noise.
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Long wheelbase The Audi A8 L (type 4N) with a long wheelbease is fitted with a two-piece glass roof. The front glass panel is movable while the rear glass panel is fixed. Since drainage in this version is possible
via the front windscreen and rear window, no drain hoses are fitted here. In both versions a glass cover is securely mounted in front of the moveable panel.
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Engines Petrol engine - diesel engine Torque/power curve of 3.0l TFSI engine EA839
Torque/power curve of 3.0l TDI engine EA897evo2
Engine with code CZSE
Engine with code DDVC
Power output in kW Torque in Nm
Power output in kW Torque in Nm
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Engine speed [rpm]
Engine speed [rpm]
Features
Specications
Engine code
CZSE
Type
V6 engine with 90° vee angle
Displacement in cm 3
2995
2967
Stroke in mm
89.0
91.4
Bore in mm
84.5
83.0
Number of valves per cylinder
4
4
Firing order
1-4-3-6-2-5
Compression ratio
11.2 1 :
Power output in kW at rpm
250at5000–6400
Torque in Nm at rpm
500at1370–4500
Fuel type
Premiumunleaded 95RON
Turbocharging
Exhaust turbocharger with wastegate
Engine management
BoschMDG1
Maximum injection pressure in bar
250
Lambda/knock control
Adaptive lambda control, adaptive knock control
Mixture formation
Directinjection
Exhaust gas treatment
2 close-coupled ceramic catalytic converters Oxygen sensor before and after catalytic converter
Emission standard
EU6plus/LEV3/Tier3
Concept
Mildhybrid48V
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DDVC V6 engine with 90° vee angle
1-4-3-6-2-5 16.0 1 : 210at4000 600from1250–3250 Diesel toEN590 Monoturbo charger with VTG and E-positioner BoschMD1withOBD 2000
Directinjection NOx storage catalyst with SCR-coated diesel particulate filter
EU6(ZD/E/F) Mildhybrid48V
Reference For further information about the utilised engines, please refer to Self Study Programme 655 "Audi 3.0l V6 TFSI engine of EA839 series" and Self Study Programme 656 "3.0l TDI engine of EA897evo2 series" 20
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Engine/gearbox combinations Use of the engine-gearbox combinations shown here is market-specific.
Engines
3.0lTFSI engine (CZSE) 250 kW
3.0lTDI engine (DDVC) 210 kW
8-speed automatic gearbox 0D5 AL552-8Q
Rear axle drive 0G2 HL195.S3 M PR no.:1) GH1
Rear axle drive 0D3 - sport dierential HL195.T2 M PR no.:2) GH2 (optional)
Key to new manufacturer code designation
e.g.: 8-speed automatic gearbox
Automatic planetary gear set
e.g.: Rear axle drive
rear
1) 2)
Longitudinal mounting
L on g i tu d i n a lm o u n ti n g
AL552-8Q
Development number (indicating torque capacity, generation and position of front final drive)
N u m b e rofg e a rs
D ri ves ys te m(all- w h ee l drive with integrated transfer case/centre differential)
HL195.S3 M
Crown wheel diameter in mm
S = Standard (unlocked differential) T = Torque Vectoring (sport differential)
1st generation 2nd generation 3rd generation
Manufacturer code: M = Magna powertrain Z = ZF Friedrichshafen AG
Production number GH1: Real axle differential basis (unlocked differential) Production number GH2: Rear axle differential torque vectoring 21
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Fuel tank The fuel tank is made of plastic and is fitted in filling levels with 72 litres and optionally with 82 litres. The interior workings are the only difference between the TFSI and TDI design. A rollover valve with a pressure retaining valve is fitted in the TFSI tank and a refuelling shut-off valve is fitted in the liquid trap.
An immersion tube with different lengths is installed in the TDI tank. A rollover valve is fitted at the bottom of the TDI/TFSI tank. The end of the valve line is found at the top in the liquid trap and also on the immersion tube.
Level sensor in the top chamber
Example: TDI fuel tank
Roll-over vent valve
Filler neck for SCR tank/AdBlue® Filler neck
Vent line
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TFSI filler neck
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Non-return flap
Baffle
Metering pump for auxiliary heater Swirl pot with integrated fuel filter in the delivery module (long life) in the TFSI tank
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Liquid trap with long refuelling shut-off valve in TFSI, 72 litres
Rollover valve with pressure retaining valve
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TDI with a long immersion tube for 72 litres
Refuelling shut-off valve
Immersion tube Liquid trap with short refuelling shut-off valve in
TDI with a short immersion tube for 82 litres
TFSI, 82 litres
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Vent line
Baffle Drive line for suction jet pump Mixer tube on the t ransfer side Level sensor in the secondary chamber Intake manifold for suction jet pump
Rollover valve for the TDI / TFSI without a pressure retaining valve; here, in the TDI, the open line terminates at the immersion tube Level sensor in the main chamber
Fuel supply line for auxiliary heater Fuel return line 662_057
Fuel supply line
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SCR system (selective catalytic reduction) The reducing agent tank is an injection moulding (not an extruded tank) made from two halves and welded. This has the advantage of reducing weight. This means that allowance can be made in the vehicle design for the integration of baffles and a heating system adapted to the cabin as installation space. The reducing agent tank has a capacity of 24 litres.
Reducing agent filler neck
Equalisation chamber
Equalisation chamber The ventilation system within the reducing agent tank is designed in such a way that the tank can be filled with AdBlue® reducing agent using pump nozzles. To be able to hold the reducing agent flowing into the tank at a high flow rate, there is an equalisation chamber in the SCR tank and in the filler neck. The returning reducing agent would otherwise cause the pump nozzle to shut off too early. To prevent the flow-back of reducing agent in the filler neck, a non-return flap is installed at the end of the filler neck.
Vent line
Reducing agent quality sensor
Filling line
In order to monitor the quality of the reducing agent (AdBlue®), a reducing quality sensor G849 is fitted thebottom reducing tank. It isagent located adjacent to the swirl pot oninthe of agent the reducing agent tank. Non-return flap
Reducing agent quality sensor G849 Outlet for draining the reducing agent
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Reducing agent metering system control unit J880
Swirl pot
Reference For further information about the SCR system, refer to Self Study Programme 632 "Audi Q7 (type 4M)".
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Swirl pot The reducing agent sensor is an e ntirely electronic component and does not require float contact points. An antenna (coil) and the reducing agent (capacitive fluid) form an electrical resonant circuit. A change in the fluid level alters the impedance of the circuit and shifts the resonance frequency (5 MHz – 12 MHz) proportional to the fluid level.
The resonance frequency is determined by a microcontroler by coupling a high frequency signal into the medium and scanning the upper frequency range. The microcontroller is located at the base of the fluid level sensor. It computes the reducing agent level using a temperature correction function. At the same time, the functioning of the tank heater is checked by determining the temperature.
Electrical connection for tank heater
Non-return flap
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Equalisation chamber in the tank
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Tank heating mat
Electrical connection for the swirl pot heater
Reducing agent tank sensor G684
Reducing agent pump (SCR metering pump) The pump is configured as a brushlessor electrically commutated three-phase motor. It pumps the reducing agent to the reducing agent injector N474 via an SCR pressure sensor. The pressure sensor for the reducing agent metering system G686 measures the outlet pressure of the metering pump to the reducing agent injector within a pressure range from -0.5 bar to approx. 9.0 bar (relative). The reducing agent temperature sensor G685 measures the reducing agent temperature within a range from -40 °C to 80 °C.
Swirl pot with reducing agent pump V437
Baffles
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Exhaust system for the 3.0l TFSI engine The gas flow paths are very short owing to the positioning of the exhaust turbocharger module in the inner V. The catalytic converter
is bolted directly to the exhaust turbocharger outlet. This allows the exhaust turbocharger to achieve light-off very quickly after a cold start.
Catalytic converter module The module is flanged-mounted directly to the exhaust turbocharger, which houses the main and secondary catalytic converters. Both catalytic converters are ceramic-type catalytic converters.
Main catalytic converter
NOx accumulator catalyst
Secondary catalytic converter Exhaust gas recirculation valve with servomotor 2 for exhaust gas recirculation V339
EGR cooler
Low-pressure exhaust gas recirculation
Flexible pipe
Centre silencer based on the absorption principle,
Decoupling element
Front silencer based on the absorption principle
Rear silencer based on the reflection and absorption principle
Note The exhaust flap is actuated by the exhaust flap control unit via a worm gear. Given that this is a "self-locking" gear, it is essential that the servomotor be removed before testing the ease of movement of the flap. 26
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Exhaust system for the 3.0l TFSI engine The exhaust gas treatment system is a combined system comprising a close-coupled NOx ammonia oxidation catalyst and an SCR system. The unit consisting of the NOx storage catalyst and the SCR-coated diesel particulate filter is followed downstream by an ammonia oxidation catalyst which, with its combined SCR and oxidation catalytic coatings, performs 2 tasks. Firstly, the CO which
occurs during soot regeneration is oxidised to CO2 by a coating containing precious metals. Secondly, NH3 slip is reliably eliminated. In order to comply with the emission standard, low pressure exhaust gas recirculation was also integrated in the exhaust treatment system.
SCR-coated diesel particulate filter
Flexible pipe
Particulate sensor NOx sensor Ammonia slip catalyst
Centre silencer based on the absorption principle Exhaust flap control unit J883
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Exhaust flap control unit J883 Rear silencer based on the reflection and absorption principle Exhaust flap control unit 2 J945
Exhaust flaps For acoustic reasons, the exhaust flap is positioned upstream of the rear silencer on the left-hand side. By positioning the flaps, 2 exhaust tail pipes can be closed, This reduces the outlet noises while the vehicle starts off.
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Reference For further information about low pressure exhaust gas recirculation, please refer to Self Study Programme SSP 656 "3.0l TDI engine - EA897evo2 series“. 27
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Power unit mounting system on 3.0l V6 TDI engine The Audi A8 (type 4N) with a 3.0l V6 TDI engine has a five-point power unit mounting system. This includes the active engine mounting, two switchable gearbox mountings and a conventional gearbox mounting. In addition, support mounting are located on the front left and right of the engine due to the absence of a torque reaction member.
Power unit mounting actuator 2 N514
This system provides enhanced ride comfort by performing the following functions: > Reduction of vibration across a wide frequency band > Positioning of the power unit in the vehicle > Reaction against drive torque > Damping of power unit vibration
Gearbox mounting valve 1 N262
Conventional gearbox mounting system
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Tie rod
Gearbox mounting valve 2 N263
Assembly mounting actuator 1 N513
Assembly mounting sensor 2 G749
Active engine mountings
Assembly mounting sensor 2 G749
The vibration transmitted from the engine is measured by power unit mounting sensors G748 and G749. They are installed on the body-side engine mounting. The measurement data converted in the sensors is sent to the power unit mounting control unit J931. This data is factored in when calculating the characteristic map. The engine speed information from the engine control unit is another important input variable. The power unit mounting control unit J931 sends the calculated control signal to power unit mounting actuators N513 and N514. Counter-vibration is produced by the active engine mountings.
Power unit mounting actuator 2 N513
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Reference For more information about the design and working principle of the active engine/gearbox mounting, refer to Self-Study Programme 607 "Audi 4.0l V8 TFSI engine with biturbo charging". 28
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Power unit mounting system on 3.0l TFSI engine The 5-point engine/gearbox mountings are also installed in the 3.0 TFSI engine. The only difference is that hydraulically switchable engine mountings are installed instead of active engine mountElectro/hydraulic engine mounting solenoid valve right N145
ings. They switch between soft during idling and hard during vehicle operation.
Gearbox mounting valve 1 N262
Conventional gearbox mounting system
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Electro/hydraulic engine mounting solenoid valve left N144
Gearbox mounting valve 2 N263
Electro/hydraulic engine mounting solenoid valve left N154
H y d ra uli ca lly s wi t cha b l e g e a rb ox m o unt i ng
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Hydraulic engine bearing
C o nventi o nal g ear bo x m o unti ng sys tem
The hydraulically switchable gearbox mounts, gearbox mounting valve 1 N262 and gearbox mounting valve 2 N263 are laterally mounted to the gearbox and counteract the torsional vibration of the power unit. They switch between soft during idling and hard during vehicle operation.
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The conventional gearbox mount is installed in the rear section of the gearbox and counteracts the load reversal and tilt functions.
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Gearbox mounting valve 2 N263 29
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Power transmission Overview This field explains the technology for the optional market launch configurations with the 3.0l TFSI (CZSE) or 3.0l TDI (DDVC) engines together with the 8-speed automatic gearbox 0D5. The 8-speed automatic gearbox and the accompanying drive concept are already in use on the Audi Q7 (type 4M). Refer to Self Study Programme 632. The gearbox has now been adapted to the Audi A8 (type 4N) and further enhanced. Refer to page 34 for more information.
8-speed automatic gearbox 0D5
The selector mechanism transmits the driver's operating requirements by means of 100% shift-by-wire technology. It is identical in design to the selector mechanism of the Audi Q7 (type 4M). Refer to Self Study Programme 632. A new design feature in the Audi A8 (type 4N) is the selector mechanism. Refer to page 32 for more information. The parking lock emergency release mechanism is the same as in the Audi Q7 (type 4M) and has been adapted for the Audi A8. Refer to page 33 for more information.
Coolant return
3.0l TFSI engine CZSE
Coolant flow
Gear oil cooling valve N509
The internal combustion engine and the gearbox in the Audi A8 (type 4N) are supported by a 5-point mounting system. Refer to page 28. The gearbox actuators, gearbox mounting valve 1 N262 and gearbox mounting valve 2 N263 are activated by the engine control unit J623.
ATF temperature regulation ATF temperature regulation is controlled via valve N509 and is explained on page 39.
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Parking lock emergency release
Selector mechanism
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Rear axle transmission As known since the Audi Q7 (type 4M), the different axle drives are mounted to the subframe by means of a 4-point mounting system. Refer to Self Study Programme 632.
The radial rubber metal bearings, except the additional bearing, must be mounted in a specified installation position according to the workshop manual.
Rear axle drive 0G2 Unlocked differential Rear axle drive 0D3 Sport differential (optional)
Sport differential The sport differential 0D3 is a further development and a new generation of the sport differential 0BF (2nd generation). In this 2nd generation two control units are responsible for activating the sport differential. The suspension control unit J775 sends the calculated redistribution of torque between the rear wheels to the differential lock control unit J1871) by means of the FlexRay bus. The differential lock control unit activates the sport differential actuators and initiates the redistribution of torque. The sport differential set-up can be influenced using the Audi drive select modes. Refer to page 41. The ATF and the axle oil of the sport differential are not subject to routine maintenance. For more information about the 2nd generation "quattro with sport differential", refer to Self Study Programmes 651 and 657.
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OD3
New: For the first time, the driver can now see the distribution of the drive torque to the individual wheels in the MMI graphic
Vehicle · quattro
display Audi A8 (type The menu "Vehicle" > "Show vehicle"in > the "quattro" must be4N). selected in theitems MMI menu for this purpose. The arrows shown on the wheels show the distribution of drive torque. 662_227
Prop shaft Rear axle drive 0G2
Rubber-metal bearing Additional bearing Rubber-metal bearing
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1)
The differential lock control unit J187 can be addressed with the diagnostic tester via address code 0032.
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Automatic gearbox selector mechanism The Audi A8 (type 4H) was previously equipped with a complete shift-by-wire selector mechanism. This means that parking lock operation is also fully automatic. The term used for this is "parkby-wire". The selector mechanism concept has been developed specially for the Audi A8 because the previous shift-by-wire concepts were still equipped with a selector lever cable for actuating the parking brake and/or the selector position sensor. Many models developed since are equipped with a complete full-by-wire selector mechanism and largely make use of a standardised selector mechanism and operating concept.
Selector lever release button E681
Selector lever
The Audi A8 (type 4N) also now uses the current selector mechanism and operating concept. Only the design has been adapted to the interior of the Audi A8. The selector mechanism and operating concept is used in the models listed below. For more information, refer to the accompanying self study programmes. Audi Q5 (type FY) Audi A5 (Typ F5) Audi A4 (type 8W) Audi R8 (type 4S) Audi Q7 (type 4M)
> Self Study Programme 657 > Self Study Programme 644 > Self Study Programme 641 > Self Study Programme 632
P button – parking lock button E816 with parking lock warning light K320
Selector lever position display Y5
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Selector lever E313 – contains the selector lever sensors control unit J5871)
1)
Plug-in connection between selector lever and vehicle
Plug-in connection to selector lever position display
The selector lever sensors control unit J587 communicates with the dash panel insert CAN bus. The data bus diagnostic interface J533 (gateway) and the FlexRay data bus system are used for communicating with the gearbox control unit. Refer to SSP 664 Data bus topology and page 40.
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Parking lock emergency release The parking lock emergency release corresponds to the design in the Audi Q7 (type 4M). The actuating mechanism is located under a cover in the driver's footwell. The parking lock can be permanently unlocked using a socket wrench in the tool kit, P-Off position.
Warning! Before actuating the emergency release device of the parking lock, the vehicle must be secured to prevent it from rolling away. If it is no longer necessary to emergency-release the parking lock, the parking lock must be locked again (P-ON position). It is necessary to check the emergency release device after assembly work on its component parts.
Emergency-releasing the parking lock (P-OFF position)
Locking the parking lock (P-ON position)
> Remove cover. > Insert the socket wrench into the actuating mechanism, position 1. > Turn the socket wrench 140° in a clockwise direction, position 2, and press down simultaneously, position 3.
Pull the socket wrench upwards out of the actuating mechanism, position 4.
When the parking lock emergency release device is actuated, the yellow gearbox warning lamp and the drive position indicator N light up in the instrument cluster. The following warming also appears: "Vehicle may roll away! P cannot be selected. Please apply parking brake."
Note: The ignition key must be turned back. This will damage the emergency release mechanism. > Fit the cover.
3 2
Cover
Socket wrench approx. 140°
1
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Actuating mechanism
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4
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Reference For more information about the parking lock emergency release mechanism in the Audi A8 (type 4N), refer to Self Study Programme 632 "Audi Q7 (type 4M)", page 48 ff. 33
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8-speed automatic gearbox 0D5 The 8-speed automatic gearbox 0D5 is an improved version of the 8-speed automatic gearbox 0BK which was first used in the Audi A8 (type 4H) in 2010. Refer to Self Study Programme 457. The 0D5 gearbox made its debut in 2016 in the Audi A7 (type 4M). At Audi the 0D5 gearbox has the internal works designation AL552-8Q. The manufacturer, ZF-Getriebe GmbH, uses the designation 8HP65A. The 0D5 gearbox is rated for peak input torque of 700 Nm. The new features of the 0D5 gearbox compared to the 0BK gearbox are described in Self Study Programme 632 "Audi Q7 (type 4M)".
The following aspects of the Audi A8 (type 4N) are new: > The MTF pump in the transfer box, previously driven by the side shaft, is no longer required. > The bearing for the drive pinion of the front axle drive has been optimised for friction by double row angular contact ball bearings. > The front axle drive is lubricated by a new low-viscosity axle oil. > The hydraulic impulse storage system, HIS for short, is replaced by auxiliary hydraulic pump 1 for gear oil V475. The auxiliary hydraulic pump provides a constant supply of ATF, assists the start-stop function and allows the internal combustion engine to be shut off under coasting in certain situations.
The software of the 0D5 gearbox still utilises the data from the navigation system to assist the star t-stop system, neutral idle control and the coasting mode. The gearbox set-up can be adjusted via Audi drive select. Refer to page 41.
Double shaft seal, planetary gearbox/transfer box1)
Transfer box vent
JTEK self-locking centre differential
MTF filler and inspection screw for the transfer box
1)
Side shaft
Oil ring
If the double shaft seal between the planetary gearbox/transfer box is leaky, either ATF or MTF will be discharge from the leak oil drainage port. Refer to Fig. 662 139, page 36. This oil seal has been replaced in all 8-speed automatic gearboxes manufactured since April 2017. Refer to the workshop manual.
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Twin-damper converter with integrated pendulum-type absorber.
Planetary gear set Front axle drive
Double row angular contact ball bearings
Double shaft seal, transfer box/ front axle drive
ATF filler and inspection screw
ATF pan made of plastic with integrated ATF suction filter
Inspection and filler screw for front axle drive
Leak oil drainage port for the double shaft seal, transfer box/front axle drive (visible from below, see page 38)
Power supply for auxiliary hydraulic pump 1 for gear oil V475 662_138
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ATF and MTF systems The 0D5 gearbox of the Audi A8 (type 4N) has 3 separate systems containing different grades of oil:
For a diagram of the drainage screws for all oil supplies, refer to Fig. 662_226 on page 38.
ATF system for the planetary gearbox and the hydraulic control unit (not subject to routine maintenance) MTF supply for the transfer box (gear oil containing STURACO1), not subject to routine maintenance) Axle oil supply for the front axle drive The new low-viscosity axle oil is not subject to routine maintenance and must not be mixed with the previous axle oil. To avoid mix-up, the new axle oil is dyed red.
The separation and sealing of these oil supply systems from one another are described in detail on page 34 in Self Study Programme 457.
Inspection and filler screw for front axle drive ATF filler and inspection screw
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MTF filler and inspection screw for the transfer box
Oil reservoir
In an MTF the transfer box is lubricated by theoil gears runningtoin thegearboxes MTF sumpwithout (oil sump). Thepump, oil reservoir is filled with the gear splash and serves distribute the oil. 1)
STURACOis an oil additive which protects against excessive stresses in the centre differential and thus helps to enhance ride comfort. Pay attention to exact assignment of gear oils in accordance with the parts numbers in the electronics parts catalogue (ETKA).
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ATFbreather
Gearbox breather
Transferboxvent
Collecting chamber
The front axle drive and the ATF system are ventilated via the collecting chamber. A breather port leads from the collecting chamber into the converter bell. The transfer box is ventilated via a separate ventilation cap. When
Ventilation port
heating or cooling the gearbox, the pressure is equalised via the gearbox vent. To allow pressure equalisation to take place, the ventilation ports must be open and unobstructed.
Leak oil drainage port for the gear set/transfer box double shaft seal
Vent for the front axle drive
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Note During transportation and when carrying out work on the gearbox, the axle oil and ATF may mix via the common gearbox vent if the gearbox is tilted too far. Follow the instructions given in the Workshop Manual. 36
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ATF supply and hydraulics In vehicles equipped with MHEV the 0G5 gearbox is supplied with ATF by 2 ATF pumps: the mechanically driven ATF pump and the electrically driven auxiliary hydraulic pump 1 for gear oil V475, which replaces the previous hydraulic impulse storage s ystem (HIS). Both pumps draw in the ATF via the ATF intake filter. Refer to page 38. The auxiliary hydraulic pump V475 now allows the internal combustion engine to be shut off under coasting. Refer to page 42.
Pump drive hub with spline, connection to torque converter
Brake A
Mechanically driven ATF pump This ATF pump is identical to the twin-stroke vane pump used in the 0BK gearbox. For more information about the mechanically driven ATF pump, refer to page 25 of SSP 457. The mechanically driven ATF pump is powered by a chain drive (magenta) via the torque converter of the internal combustion engine. When the ATF pump reaches the required speed, a gearbox input speed of about 500 rpm2), it is able to provide a reliable supply of ATF without the auxiliary hydraulic pump.
Impeller shaft
Sun gear shaft S1/S2 Chain drive ATF pump, mechanically driven
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Auxiliary hydraulic pump 1 for gear oil V475 By assisting the mechanically driven ATF pump, the auxiliary
If the vehicle is coasting and the internal combustion engine is
hydraulic V475 provides a reliable supply of ATF for the start-stoppump and coasting functions of the gearbox.
shut off, the mechanically driven ATF pump stops circulating ATF.
If the auxiliary hydraulic pump is unable to circulate ATF because the overload cut-out has tripped or a fault has occurred, the start-stop and coasting functions are no longer available.
In this case, the auxiliary hydraulic pump runs at maximum output to ensure a full supply of ATF. This makes sure that the gearbox is adequately lubricated and enables the gears to be preselected depending on the speed at which the vehicle is travelling. Refer to page 42.
If V475 is faulty, the yellow gearbox warning lamp lights up.
For further detailed information about the auxiliary hydraulic pump 1 for gearbox oil V475, refer to Self Study Programme 649 on Page 43.
The auxiliary hydaulic pump V475 is used within an ATF temperature range from 20 °C to 125 °C2) and has 3 output levels. The pump communicates with the gearbox control unit J217 via a LIN bus line. The auxiliary hydraulic pump provides a reliable and quick supply of ATF. This aids disengagement of the parking lock and allows delay-free start-up. If the mechanically driven ATF pump reaches the required speed and is capable of supplying system pressure by itself, the auxiliary hydraulic pump receives the instruction via LIN bus to stop circulating ATF.
Pump electronics – integrated into housing Ground contact for voltage supply
Terminal 30, positive contact to power supply Connection, pressure side
LIN bus connector
Brushless DC motor ATF suction filter G-rotor pump with non-return valve 2)
The values given are intended as a guideline and are not binding. They may deviate depending on the model version.
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Mechatronic module The mechatronic module of the 0D5 gearbox in the Audi A8 (type 4N) has the works designation E 26/29 at ZF-Getriebe GmbH and is identical to that of the 0D7 gearbox in the Audi Q7e-tron quattro (type 4M). The sensors, actuators and design configuration of the electrohydraulic parking lock of the 0D5 gearbox are identical to those of the mechatronic module of the 0BK gearbox. Refer to Self Study Programme 457. The auxiliary hydraulic pump 1 for gear oil V475 is now used in place of the hydraulic impulse storage system (HIS).
For more information about the mechatronic module E26/29, the hydraulic interfaces and the auxiliary hydraulic pump, refer to Self Study Programme 649.
Oil bleed port for double shaft oil seal, transfer box/front axle drive
Filler and inspection screw for front axle drive
Plug-in connection to auxiliary hydraulic pump V475 Drain screw, front axle drive
ATF filler and inspection screw
Power supply for auxiliary hydraulic pump V475 MTF drain screw for transfer box
MTF filler and inspection screw for transfer box
Connector housing for plug-in connection to vehicle
Mechatronic module Plug-in connection to vehicle
LIN bus connector
Auxiliary hydraulic pump 1 for gear oil V475 LIN bus connector (V475) Plastic ATF pan ATF drain screw
ATF suction filter 662_226
Auxiliary hydraulic pump intake port
Note Protect the mechatronic module against electrostatic discharge. Please refer to the guidelines provided in Self Study Programme 284 "6-speed automatic gearbox 09E in the Audi A8 ’03 part 2", page 6, and in the Workshop Manual. 38
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ATF temperature regulation Like in the Audi Q7 (type 4M), the ATF heat exchanger is flooded, i.e. perfused with coolant, by a circuit switched parallel to the large coolant circulation system of the engine. The coolant circulation system is controlled by the ATF heat exchanger via valve N509.
Engine warm-up phase (N509 closed)
Heating and cooling of the ATF (N509 open)
Valve N509 is energised, and therefore closed, during the engine warm-up phase. The ATF heat exchanger is not flooded with coolant. Since the coolant does not give off any heat to the ATF, the engine reaches its operating temperature more quickly. The thermal management system of the engine control unit decides when valve N509 is to be opened. The criteria for opening valve N509 are the ambient temperature, the engine temperature, the ATF temperature, the engine speed and the heat demand of the Climatronic.
If the engine has reached its operating temperatue and there is sufficient heat for every requirement, valve N509 opens. The ATF heat exchanger is therefore flooded with warm coolant from the large engine coolant circuit. This warms the ATF and reduces its viscosity, which in turn increases the efficiency of the gearbox. The ATF is heated as long as the temperature of the engine coolant exceeds that of the ATF. When the temperature of the ATF exceeds the temperature of the engine coolant, the ATF dissipates its heat to the coolant and is cooled.
ATF supply line ATF return line
N509
2
1 ATF heat exchanger
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2 1
Gear oil cooling valve N509 ATF return line
N509Gear oil cooling valve > de-energised and open > de-energised and closed > is actuated by the gearbox control unit J217. The gearbox control unit J217 receives the command to open or close valve J509 from the thermal management system of the engine control unit. > Actuator test using Guided Fault Finding
ATF supply line
ATF heat exchanger 662_148
Note If the ATF cooler is leaking, coolant (glycol) will mix with the ATF. Even the smallest quanties of coolant in the ATF can have a detrimental effect on clutch control. A glycol test will show up even the smallest quantities of glycol and can, therefore, be used to rule out this cause. 39
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Data exchange – Function diagram The gearbox control unit (J217) communicates with the vehicle periphery via the FlexRay data bus system. The data bus diagnostic interface J533 (gateway) and the dash panel insert CAN data bus are used for communicating with the selector mechanism (selector lever sensors control unit J587). Refer to Data bus topology in Self Study Programme 664.
Functional diagram of the 8-speed automatic gearbox 0D5 in the Audi A8 (type 4N)
P/N signal, start enable signal to J623
FlexRay, to J533 FlexRay, to J533 FlexRay, to J500 FlexRay, to J500
Ground activation N509
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Key: Ground cable Positive cable Signal line LIN bus
N88 Solenoid valve 1 N215 Pressure control valve 1, brake A N216 Pressure control valve 2, brake B N217 Pressure control valve 3, clutch C
Transmitted signal Received signal FlexRay line
N218 Pressure control valve 4, clutch D N233 Pressure control valve 5, clutch E N371 Pressure control valve 6, torque converter lockup clutch N433 Pressure control valve 7, system pressure N486 Parking lock solenoid N509Gear oil cooling valve
G93 ATF temperatur sensor G182 Gearbox input speed sensor G195 Gearbox output speed sensor G510 Temperature sensor incontrol unit G747 Parking lock sensor J217 J500 J533 J623
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Automatic gearbox control unit Power steering control unit Data bus diagnostic interface J533 (gateway) Engine control unit
V475 Auxiliary hydraulic pump 1 for gear oil
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Functions influencing the gearbox and sport differential Audi drive select Audi drive select can be used to select between different vehicle configurations, i.e. modes. The following Audi drive select modes can be selected by pressing the Audi drive select button or via the MMI. In this chapter you will learn how the gearbox control unit and the sport differential respond to the various Audi drive select modes. Gearbox setups are tailored to the customer's requirements in a country-specific way. For this reason, only typical differences between the various modes can be shown here.
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efficiency mode
auto mode
Gearbox: An E is displayed in the gear selection indicator as the selector position (E1 – 8). The shift points are selected with a defined shift program without driver type recognition. The upshifts are executed as early as possible and the downshifts as late as possible. In addition, the engine power output is reduced, whereupon the gearbox control unit reduces the clutch pressure accordingly. This improves fuel economy and reduces CO2 emissions.
Gearbox: The shift points in selector positionsD and S are selected according to the driver type recognition characteristics. For this purpose, the system evaluates the way in which the vehicle is being driven. The system factors in the way in which the brake and accelerator pedals are applied as well as the transverse and longitudinal acceleration of the vehicle within defined periods. Accordingly, an economical driving style leads to early upshifts and late downshifts. A sporty driving style is made possible by late upshifts and early downshifts. The driving phases in which the driver adopts an efficient, economical, sporty or manual driving style can be read out using the diagnostic tester.
Sport differential: The set-up for the sport differential is moderate, i.e. steering behaviour is not adjusted for faster response. If the vehicle is equipped with an efficiency assist system, an active flow of information takes place via the symbols in the efficiency assist system in order to show the driver an economic driving style.
Selector position D:
comfort mode
The shiftof points are selected in a comfort-oriented way after taking account the ascertained driver type.
Gearbox: The gearbox control unit behaves in the same way as inauto mode.
Selector position S1): In selector position S the gearbox control unit runs in sport mode. The shift points are selected in the sport mode after taking account of the ascertained driver type and are adapted to the performance range of the engine. The shift times vary from normal, with barely perceptible gear shifts, to short, with noticeable gear shifts.
Sport differential: The set-up for the sport differential is moderate, i.e. steering behaviour is not adjusted for faster response.
dynamic mode Gearbox: If dynamicmode is selected, the gearbox control unit activates the sport program (selector position S). In dynamicmode the selector positon D can be selected at any time. If selector position D is activated before shutting off the engine, selector position (D) is again activated when the engine is subsequently started 1). If the driver wants to have selector positionS, he must select this. 2) Sport differential : The torque redistribution set-up provides for highly responsive steering with a slight tendency to to ovesteer. Only in the event of pronounced oversteer is the torque redistributed to stabilise the vehicle on the rear axle.
If the vehicle is equipped with an efficiency assist system, the driver does not receive any information in sport mode via the symbols of the efficiency assist system. Sport differential: The set-up for the sport differential is balanced. The adjustment to steering behaviour ensures neutral handling. The vehicle is stabilised if an oversteer tendency is detected.
individual mode The menu item "Driveline" encompasses the engine, the gearbox and the sport differential. The driver can select from efficient, balanced and sporty options under this menu item. These following drive select modes are assigned to these options: > efficient equivalent to the efficiencymode of Audi Drive select > balanced, equivalent to theauto mode of Audi Drive select > sporty, equivalent to the dynamicmode of Audi Drive select
1)
The vehicle is always restarted in the combination of Audi drive select mode auto and selector position D. 2) If the vehicle detects that a trailer is being towed, the set-up of the sport differential is set within the system toauto. 41
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Intelligent coasting mode With the auxiliary hydraulic pump 1 for gear oil V475 in the 8-speed automatic gearbox 0D5, it is now possible, for the first time, to shut off the internal combustion engine under coasting to make additional fuel savings. However, shut-off of the engine may be suppressed due to certain events, such as: > If a defined engine temperature has not yet been reached. > If the power demand of the air conditioning system requires that the engine be running. > If a corrective input by ESC requires that the e ngine be running. > If an adaption routine of the engine control unit is in progress. > If the diesel particulate filter regeneration cycle is in progress. If the switch-on conditions shown adjacent are met, the tractive connection between the engine and the gearbox is disengaged. The vehicle uses the existing brake energy in coasting mode and rolls without an engine braking effect. Only selector position D or E is displayed in the gear indicator; the gears are not shown. Depending on the speed at which the vehicle is travelling, the gears are preselected in the background while the engine is disengaged from the transmission. The following of the five gear-shift elements act as disconnecting elements: > Gear 8: > 3000 rpm gearbox output speed: Clutch D > Gear 8: < 3000 rpm gearbox output speed: Brake A > Gears 7, 6, 5, 4: Clutch D > Gears 3, 2: Clutch E > Gear 1: Clutch C To be able to hold and preselect gears while the internal combustion engine is shut off, auxiliary hydraulic pump 1 for gear oil V475 is required. V475 maintains the necessary supply of ATF while the internal combustion engine is shut off. Refer to page 37. Gears 4 and 7 are a special case. If the vehicle is in one of these gears, coasting mode is activated by opening clutch D. However, gears 4 and 7 are skipped when the system preselects gears, as critical speeds can occur in the gearbox if clutch D is open these gears. This means that when coasting mode is activated in 8th gear and the vehicle is gradually decelerating, 8th gear is held until the gearbox is able to shift down into 6th gear. The same applies to 4th gear. In this case, the gearbox holds 5th gear until it can shift down into 3rd gear.
Switch-on conditions: > The intelligent coasting mode must be activated via the MMI display2). > ESC is active. > Selector position D or E must be sele cted. > Vehicle speed between 160 and 55 kph1). > Coasting mode (accelerator pedal not pressed) > Uphill gradient < 3%1) and downhill gradient < 4%1), the gradient of the road is determined by the longitudinal acceleration sensor of the brake electronics. > Situation-based activation by efficiency assist3): If the vehicle is equipped with a navigation system4) and the optional adaptive cruise assist system, efficiency assist is, if cruise control is active, able to activate coasting mode in specific situations. The efficiency assist system utilises the route data provided by the navigation system.
Shut-off conditions: > Uphill or downhill gradient > 10%1) > Max. speed: > > 170 kph1) > < 8 kph1) (when the brake is not applied5)) > Pressing the accelerator pedal > Applying the brake: > > 30 kph1) as soon as the brake light switch is activated > < 30 kph1) when a preset brake pressure threshold is exceeded > ESC is deactivated. > Selector position S is selected. > tiptronic mode is activated via the tiptronic gate or by se lecting with the tiptronic paddleby onefficiency the steering wheel. 3) > TipSituation-based deactivation assist : If the vehicle is equipped with a navigation system4) and the optional adaptive cruise assist system, efficiency assist is, if cruise control is active, able to deactivate coasting mode in specific situations. This takes place regardless of the vehicle's speed, e.g. if the vehicle is approaching a built-up area or a roundabout. Coasting mode is also suppressed when the vehicle approaches other road users. > No ATF circulation by auxiliary hydraulic pump 1 for gear oil V475 due to overload protection function or fault.
Note: When the vehicle is running in coasting mode with the engine shut off, delayed acceleration may be noticeable because the internal combustion engine possibly has to be started and the corresponding disconnecting element closed before the vehicle can accelerate.
Start-stop system The start-stop system is activated automatically whenever the ignition is turned on. It helps to save fuel and reduce C02 emissions. If the requirements for start-stop operation have been met, the engine is shut off automatically when the brake is applied at a speed of 22 kph or less. One of these conditions is that the selector lever is not in position R. The engine is automatically restarted when required. The requirements for this are a very short start
time and quick readíness for drive-away. In the Audi A8 (type 4N) with MHEV equipment quick readiness for drive-away is ensured by the auxiliary hydraulic pump 1 for gearbox oil V475. If the auxiliary hydraulic pump is unable to circulate ATF because the overload cut-out has tripped or a fault has occurred, the start-stop function is deactivated and is no longer available.
Reference The shift schematic of the 0D5 gearbox is identical to that of the 0BK and 0BL gearboxes. Refer to Self Study Programme 457 "Audi A8 ’10 Power transmission", pages 28 and 44 ff. More information about the MHEV (mild hybrid electric vehicle) can be obtained through Service TV programme "STV_0484_Audi Hybrid Technology – Overview". 42
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Neutral idle control Neutral idle control is market-dependent. The neutral idle control system disengages the engine from the gearbox when stopping or when the vehicle is stationary. Engine idle torque can be reduced to a minimum because the engine does not have to counteract the converter torque.
This helps save fuel and reduces C02 emissions. In addition, the engine runs more smoothly and quietly at low idle torque. For this reason, the neutral idle control system is activated as often as possible (see conditions for switching on and off).
Switch-on conditions: > Full adaption of the shift elements (brakes, clutches) 1) > ATF temperature > approx. 20 °C > Gradient < 4%1) (the gradient is determined by the longitudinal acceleration sensor of the brake electronics) > Selector position D or R > Accelerator not pressed > Foot brake pressed
Shut-off conditions: > Selector position S6) or tiptronic mode > Brake released (unless the vehicle is secured by the electro-mechanical parking brake or hill start assist is active) > Accelerator pressed > No ATF circulation by auxiliary hydraulic pump 1 for gear oil V475 due to overload protection function or fault. > Towing mode detected
Downhill assist Downhill assist helps the driver to maintain a constant speed on downhill gradients. In this case the gearbox selects the gear suitable for the graident in order to maintain the speed selected at the time of braking via the engine brake. Within the bounds of the system's physical limitations it may be necessary to also correct the speed, if necessary, using the brake pedal. Downhill assist cuts out again as soon as the gradient lessens or the accelerator pedal is pressed.
Depending on the gradient, downhill assist is active in selector positions D and S while the brake is applied or while cruise control is active. Note: Downhill assist cannot overcome the physical limitations of the vehicle and therefore cannot maintain a set speed in all conditions. The driver must always be ready to apply the brakes!
Special features of the steering wheel tiptronic function > After a long pull of the Tip- shift paddle (long pull-), the gearbox changes down into the lowest possible gear. > After a long pull of the Tip+ shift paddle (long pull +), the gearbox switches from temporary tiptronic mode to automatic mode. > In the event of a malfunction of the selector mechanism, the positions P, R, N and D can be selected when the vehicle is stopped and the brake is activated by simultaneously pressing bothshift paddles (> 1 sec.).
> The "Tip-shifting in D/S" function, which allows gearshifts to be performed manually at any time, is available. For more information about this function, refer to page 47 of Self Study Programme 632 and page 61 of Self Study Programme 644. > The "Activation of coasting mode using Tip+" function has been deactivated in order to simplify the function assignments of the tiptronic steering wheel in the Audi A8 (type 4N). However, it is still possible to exit coasting mode by pressing Tip-.
Note:The shift paddles for the steering wheel tiptronic function are an optional (country-specific) feature of the s teering wheel. 1) 2)
The values given are intended as a guideline and are not binding. They may deviate depending on the model version. Efficiency assist can be selected together with the "Intelligent coasting" and "Predictive messages" functions in the MMI display under Car → Driver assist →. These functions can be activated or deactivated here. The intelligent coasting mode is also available without the navigation system. Efficiency assist decides, depending on the situation, whether coasting mode is to be activated or whether brake energy is to be recuperated by the starter generator in overrun mode. Predictive messages can only be displayed with the aid of the navigation system. If the "Predictive messages" function is activated, a symbol shows the driver that he must take his foot off the accelerator pedal as soon
an event occurs which requires a lower speed. Efficiency assist is an integral part of the engine management system. The navigation system is optional and is not available in some markets. If the vehicle is equipped with a navigation system, its data on the route ahead is utilised. Refer to "Navigation-based gear selection", Self Study Programme 457 "Audi A8 ’10 Power transmission", page 58. 5) If the brake is applied and the brake pressure is below a preset threshold, coasting mode is maintained until the vehicle comes to a standstill (0 kph). 6) Neutral idle control is not activated in selector position S in order to allow more direct drive-away. Without neutral control, clutch C or D is immediately closed when drive positions S1 and R are selected. This is why traction is noticeable on selection of 1st gear or R gear and likewise the traction reversal when shifting from 1st gear to R gear (or vice versa). This traction reversal is barely noticeable in selector position D, because when neutral control is active clutch C or D is open and traction cannot be established until the brake has been released. 3) 4)
Reference For more detailled information about the neutral idle control functionm in the 0D5 gearbox, refer to page 52 of Self Study Programme 632 "Audi Q7". 43
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Suspension Overview The chassis of the Audi A8 (type 4N) has been completely redesigned. New technologies and control systems make it even more comfortable, sportier and safer, All the available chassis are e quipped with air suspension featuring electronic damping control As high-precision, responsive five-link designs, both the front and rear axles are largely made of light aluminium. The basic trim comes with progressive-rate steering which reduces the steering effort required of the driver. The optional dynamic all-wheel-drive steering system, used here for the first time by Audi, combines dynamic steering and rear axle steering. The system improves important subjective and objective driving dynamic characteristics.
The brake system offers high performance reserves. A ceramic brake system wheel is optional. With the 9th generation ESC from Robert Bosch GmbH an efficient system is available for all relevant control functions. A wide range of steering wheels, wheels and tyres is available for customisation. ACC is, for the first time, an integral part of adaptive cruise control, the new driver assistance system in the Audi A8 (type 4N). Refer to Self Study Programme668 for detailed information. For detailed information about the chassis of the AudiA8 (type 4N), refer to Self Study Programme663.
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quattro all-wheel drive as standard with all AudiA8 (type 4N) suspension systems. The following suspension variants can be ordered: > Adaptive air suspension (1BK) This suspension system is the basic equipment. > Adaptive air suspension sport (2MA) This suspension system is optional equipment. Suspension and damping are set up for distinctly sporty handling.
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Axles and wheel alignment Front axle The front axle is based on the proven design principle of the five-link axle. Special attention was paid to lightweight construction during design.
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Rear axle The trapezoidal link rear axle in the predecessor model has been replaced by a newly developed five-link axle. The geometrical arrangement of the links ensures good separation between longitudinal and lateral friction force. Elastomer bearing with highly
dampening material mixtures and integrated intermediate sleeves permit high radial rigidities with low secondary spring rates. Thanks to the standard use of hydraulically damping axle carrier mounts, good insulation is ensured between the axle and chassis. Friction-optimised wheel bearings help to reduce tyre resistance.
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Wheel alignment The wheel alignment and suspension setup procedures are identical to those for the Audi A4 and Q7 models. The setting points are also identical.
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Adaptive air suspension (aas) The two suspension versions - adaptive air suspension and adaptive air suspension sport - are distinguished by different control characteristics. The system configuration basically corresponds to that of the aas systems in the Audi Q7 and Q5 models. As in the predecessor model, suspension struts are used on the rear axle of the Audi A8 instead of separate spring and damper layouts. In this case, too, the suspension control unit J775 is used. In addition to the control software for the air suspension and damping systems,
Suspension strut with damper with damping adjustment valve, front right N337
the control unit houses sensors for measuring vertical acceleration as well as pitch and roll (torque about the longitudinal and transverse axes of the vehicle). This eliminates the need for the body acceleration sensors required by earlier systems. The control software receives the measurement data on yaw rate (torque about the vertical axis of the vehicle) and transverse acceleration from the airbag control unit J234 via the FlexRay bus.
Suspension control unit J775 incorporates the control software for air suspension and damping as well as sensors for measuring vehicle dynamics
Suspension strut with damper with damping adjustment valve, rear left N338
Air supply system with compressor V66 and solenoid valve block
Vehicle level sensor, front right G289
Pressure accumulator
Suspension strut with damper with damping adjustment valve, rear right N339
Vehicle level sensor, front left G78
Suspension strut with damper with damping adjustment valve, front left N336
Vehicle level sensor, rear left G76
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Steering system Electromechanical progressive-rate steering The Audi A8 uses well-proven electromechanical steering system used previously in the Audi Q7 (type 4M). Progressive steering is standard. An electrically adjustable steering column is basic equipment. For customisation, a wide range of steering wheels is available.
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Dynamic all-wheel-drive steering As a logical development of the all-wheel-drive steering system, offered for the first time in the Audi Q7 (type 4M), a new system - dynamic all-wheel-drive steering - is optional in the Audi A8 (type 4N). A new feature is the combination of rear axle steering and dynamic steering. This allows the front and rear axles to implement defined steering angles independent of the driver.
This improves key subjective and objective dynamic steering characteristics, such as: > Smaller turning circle > Reduced steering effort > Much better agility, particularly at low and medium speeds > Improved driving stability, specifically during lane-changing and manoeuvres > evasive Improved response and faster vehicle reaction times
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Suspension Brake system
Front wheel brake
The Audi A8 (type 4N) is equipped with a generously dimensioned brake system which offers a high performance reserves. Front axle 17 – 18" 6-piston brake calipers are used on the front axle. 10-piston brake calipers are available as an option in combination with the ceramic brakes.
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Rear axle
Rear wheel brake with EPB
The rear axle brake calipers (17" and 18", 19" for ceramic brakes) come equipped with the electromechanical parking brake (EPB). As previously in the current Q7, Q5 and A4 models, the front and rear wheel brakes in the Audi A8 have separate brake circuits ("black and white" layout).
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Brake booster
Brake booster
9/9" tandem brake boosters are used for both left-hand-drive and right-hand-drive models.
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ESC unit ESC unit
ESP 9 is used in the Audi A8 (type 4N). Depending on trim level, brake pressure is built up by hydraulic pumps with 2 or 6 pistons. In the basic trim of the vehicle, pumps with two pistons are used in combination with a pressure sensor for measuring the pilot brake pressure. Vehicles with ACC are equipped with the 6-piston version. Here, two additional pressure sensors measure the pressures in both brake circuits. A new function is the loose wheel detection function. Loose wheels are detected by evaluating the wheel vibrations. If a loose wheel is detected, the driver receives a warning.
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Wheels and tyres In the basic trim, the Audi A8 (type 4N) comes with 17 – 19" wheels depending on engine size. 18 – 20" wheels are optional. The range of tyres extends from 235/60 R17 to 265/40 R20. Tyres with run flat capability are not available.
The Tire Mobility System (TMS) is standard equipment. A space saver spare wheel is optional. The car comes with a jack if ordered factory-fitted with winter wheels and if equipped with a space saver wheel.
Tyre pressure monitoring system As an alternative to the tyre pressure loss indicator as standard equipment, the 3rd generation tyre pressure loss indicator is available as an option in the Audi A8 (type 4N). The system is identical in design and working principle to that of the Audi Q7 (type 4M).
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Electrics and electronics The Audi A8 (type 4N) represents the future of the luxury class in the area of vehicle electrics and electronics. Highlights of the vehicle electrics are: > Matrix LED headlights with Audi laser lights > Rear LED strip with tail lights incorporating OLED technology > Matrix LED reading lights > Rear Seat Remote with OLED display
> 48-volt main electrical system with mild hybrid technology > All units are equipped with a belt starter generator (RSG) > Heated armrests in the doors, front and rear centre armrests as well as a heated steering wheel > 14.1 kWh lithium-ion battery under the luggage compartment floor
J387
J428 J1023
J364
A27 R161 J1089 J521 J794
J792
J500
J1122
R242
J234
J245
J764 J898
J1088
J285
J527
J104 A31
J869
J136
J853
J1121
J519
J1018 J623 J931
J386
Key: A6 A7 A27 A31
Battery, 48 V Torque converter, 48 V/12 V Right LED headlight power module 1 Left LED headlight power module 1
J386 J387 J392 J393 J428
Driver side door control unit Front pass. side door control unit Rear sliding sunroof control unit Central comfort/convenience system control unit ACC control unit
J104 J136
ABS control unit Seat and steering column adjustment control unit with memory function Differential lock control unit Airbag control unit Sliding sunroof adjustment control unit Control unit in dash panel insert Trailer recognition control unit Auxiliary heating control unit
J500 J502 J505 J519 J521 J525 J527 J533 J605
Power steering control unit Tyre pressure loss indicator control unit Heated windscreen control unit Electrical system control unit Front pass. seat adjustment control unit with memory Digital sound package control unit Steering column electronics control unit Data bus diagnostic interface Rear hatch control unit
J187 J234 J245 J285 J345 J364
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Installation locations of the control units Several of the Audi A8 (type 4N) control units listed here are optional or country-specific equipment. For the sake of clarity, not all control units fitted in the vehicle can be shown here.
J927 R78 A7
J880
J505
J775
J392
J533
J769
J187
A6
J1019
J 77 2
J502 J605
J525 J345
J393
J770
J926
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J623 J764 J769 J770 J772
Engine control unit Electrical steering column lock control unit Audi side assist control unit Audi side assist control unit 2 Rear-view camera system control unit
J931 J1018 J1019 J1023 J1088
J775 J792 J794 J853 J869 J880 J898 J926 J927
Suspension control unit Active steering control unit Information electronics control unit 1 Control unit for night vision system Structure-borne sound control unit Reducing agent metering system control unit Control unit for windscreen projection (head-up display) Rear driver side door control unit Rear pass. side door control unit
J1089 Control unit for front right radar sensor for object detection J1121 Driver assistance systems control unit J1122 Laser distance measurement control unit R78 R161 R242
Power unit mounting control unit Left control unit for light control Rear axle steering control unit Right control unit for light control Control unit for front left radar sensor for object detection
TV tuner DVD changer Front camera for driver assist systems
Note Refer to the current service literature for details of control unit installation positions, as well as instructions for installation and removal. Service literature For further information about the vehicle electrics and electronics of the Audi A8 (type 4N), refer to Self Study Programme 664 "Audi A8 (type 4N) - Electrics and electronics". 51
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Air conditioning Introduction of the new R744 refrigerant Audi has been using the R1234yf refrigerant as standard since 2016. An additional, new refrigerant is used in the Audi A8 (type 4N): carbon dioxide. It has the chemical formula CO2
and is also known as R744. It contains neither fluorine nor chlorine and is produced in a series of natural processes without depleting the earth's ozone layer.
Components of the R744 refrigerant circuit
Connection to air conditioner with evaporator Service connection, low pressure side Service connection, high pressure side
Expansion valve Refrigerant pressure and temperature sensor, low pressure side G1052 Accumulator
Internal heat exchanger
Pressure relief valve, low pressure side
AC compressor with pressure relief valve, high pressure side
Gas cooler Refrigerant pressure and temperature sensor, high pressure side G1053
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Properties of the R744:
System pressure
The essential difference between the new air conditioning system and previous air conditioning systems is the high working pressures in the system. These are required in order to use CO2 as a refrigerant.
> Up to 93 bar on the low pressure side > The maximum system pressure on the high pressure side is 140 bar.
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New features of the Audi A8 Cabin fragrance system
Air improvement system
There is a choice of 2 different fragrances in the new Audi A8 (type 4N): a summer fragrance and a winter fragrance. The fragrances are stored in 2 cylindrical flacons in the cabin fragrance system function unit GX43, which is located to the left of the steering wheel below the dash panel. A small fan the blows the fragrance from the flacon into the outer front air outlets. There is a choice of various aroma intensity levels.
To improve air quality, ionisers are used in the new Audi A8 (type 4N). Ionisers improve air quality through the controlled negative charging of air particles before they are discharged into the cabin via the outer front air outlets.
Surface heating The armrests in the door trims as well as the centre armrests in the front and rear are heated surfaces. The heating function is activated and controlled through the seat heater. All heated surfaces are deactivated and regulated through the seat heater.
Depending on trim level, three surface heating variants are available: > for the front seats only > for the rear seats only > front front and rear seats
Foot heater
Foot massage
The foot heater in the footrest in the comfort individual contour seat with reclining seat function can only be activated in the unfolded position and in the rest position of the seats. It can be operated through the Smart Remote Control unit and,
The massage program offers two options allowing the soles of the feet to be massaged either by the linear application of pressure by massaging the reflex zones.
like the seat heater and the seat ventilation system, is adjustable to three levels.
Back massage An improved back massage feature is available in the new Audi A8 (type 4N). For this purpose, up to 16 bladders are integrated in the front seat and up to 18 in the rear seat. In standard
trim, the seats are equipped with double lift bladders. The optional triple lift bladders are designed to provide a higher intensity back massage.
AC control panels in the front and rear The A8 (type 4N) no longer requires the Climatronic control unit J255. This means there is no need for a separate AC control unit. The AC is operated via 2 touchscreens.
touchscreen are installed at the centre of the dash panel and at the centre of the centre console respectively. The AC functions in the upper MMI display can be accessed through the Car menu. Various
In terms of visual appearance and tactile feel, both displays are the key innovation in terms user operation. The MMI display and the
control panels are available in the rear area, depending on trim level.
Reference For further information about the air conditioning system, refer to Self Study Programme 665 "Audi A8 (type 4N) New air conditioning features and introduction of refrigerant R744“. 53
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Safety and driver assistance systems Passive safety
In-car airbags
On the following pages you will find a summary of the occupant protection system in the Audi A8 (type 4N).
Front pass. airbag
Passenger side knee airbag
Front interaction airbag
Driver airbag
Driver side knee airbag
Components
Front side airbag
Depending on country version and trim level, the passive occupant and pedestrian protection system in the Audi A8 (type 4N) can comprise the following components and systems: > Airbag control unit > Adaptive driver airbag > Adaptive front passenger airbag + (front passenger airbag, two-stage country version) > Front side airbags > Side airbags, 2nd seat row
> > > >
> > > > > > > > > >
tensioners for driver and front passenger sides (equipment version) > Lap belt tensioner for 2nd seat row for driver and front passenger sides (equipment version) > Seat belt warning for all seats (country version) > Seat occupancy sensor in front passenger seat > Front pass. airbag disabling switch (country version) > Front passenger airbag OFF and ON warning lamp > Driver and front passenger seat position sensors > Trigger for pedestrian impact mitigation system (country version) > Battery isolator, 12-volt electrical system > Battery isolator, 48-volt electrical subsystem > Battery isolator of high-voltage system
Head airbags Knee airbag (country version) Front interaction airbag (equipment version) Interaction airbag, 2nd seat row (equipment version) Active front head restraint (equipment version) Front airbag crash sensors Crash sensors for side impact detection in the doors Crash sensors for side impact detection in the C posts Crash sensor for side and longitudinal impact detection Centre crash sensor for pedestrian impact mitigation system (acceleration sensor, country version) > Left and right crash sensors for pedestrian impact mitigation system (pressure sensors, country version) > Left and right crash sensors for pedestrian impact mitigation system (acceleration sensors, country version) 54
Front inertia-reel seat belts with pyrotechnic belt tensioners Front inertia-reel seat belts with electric seat belt tensioners Front inertia-reel seat belts with active belt force limiters Inertia-reel seat belts for 2nd seat row with pyrotechnic belt tensioners for driver and front passenger sides > Inertia-reel seat belts for 2nd seat row with pyrotechnic belt
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Headairbag, driver and front passenger sides
Side airbag, 2nd seat row
Interaction airbag, 2nd seat row
Side airbag, 2nd seat row
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Note The diagrams in the chapter "Passive occupant safety" are schematic diagrams designed to aid understanding.
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System overview The system overview shows the components for all markets. Keep in mind that this constellation is not possible in a production model.
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Additional equipment Equipment specifications may vary due to the different requirements and statutory provisions which apply to vehicle manufacturers in various markets.
Key to figure onpage 56: E24 Driver side seat belt switch E25 Front pass. side seat belt switch E224 Airbag disabling switch, front pass. side
J1098 Rear right seat belt tensioner control unit K19 Seat belt reminder warning lamp K75 Airbag warning lamp K145 Front pass. airbag OFF warning lamp (ON and OFF status of front pass. airbag is indicated)
F390 Driver side seat belt switch, 2nd seat row F391 Centre belt switch, 2nd seat row F392 Front pass. side seat belt switch, 2nd seat row G128 G179 G180 G256 G257 G283 G284 G551 G552 G553 G554 G570 G571 G598 G599 G693 G851
Front pass. side seat occupancy sensor Side airbag crashsensor, driverside Side airbag crash sensor, pass. side Rear side airbag crash sensor, driver side Rear side airbag crash sensor, pass. side Front airbag crash sensor, driver side Front airbag crash sensor, pass. side Belt force limiter, driver side Belt force limiter, pass. side Seat position sensor, driver side Seat position sensor, pass. side Driver side crash sensor for pedestrian protection Pass. side crash sensor for pedestrian protection Pedestrian protection system trigger 1 Pedestrian protection system trigger 2 Centre crash sensor 1 for pedestrian protection system Driver side crash sensor 2 for pedestrian protection system
G852 Front pass. side crash sensor 2 for pedestrian protection system G858 Centre crash sensor for X/Y axis J234 Airbag control unit J285 Control unit in dash panel insert J519 Electrical system control unit J528 Roof electronics control unit J533 Data bus diagnostic interface (gateway) J706 Seat occupancy recognition control unit J854 Front left seat belt tensioner control unit J855 Front right seat belt tensioner control unit J1097 Rear left seat belt tensioner control unit
N95 N131 N132 N153 N154 N196 N197 N199 N200 N201 N202 N251 N252 N253 N295 N296 N419 N420
Driver side airbag igniter Front pass. side airbag igniter 1 Front pass. side airbag igniter 2 Seat belt tensioner igniter 1, driver side Seat belt tensioner igniter 1, pass. side Rear seat belt tensioner igniter, driver side Rear seat belt tensioner igniter, pass. side Side airbag igniter, driver side Side airbag igniter, pass. side Rear side airbag igniter, driver side Rear side airbag igniter, pass. side Head airbag igniter, driver side Head airbag igniter, pass. side Battery isolation igniter Driver side knee airbag igniter Pass. side knee airbag igniter Driver side active head restraint igniter Pass. side active head restraint igniter
N490 N491 N563 N737
N749 N750 N751
Driver airbag reliefrelief valvevalve igniter Front pass. airbag igniter High-voltage battery isolator igniter Igniter for interaction airbag for occupant collision protection, driver side Igniter for interaction airbag for occupant collision protection, driver side, 2nd seat row Seat belt tensioner igniter 2, rear driver side Seat belt tensioner igniter 2, rear pass. side 48 volt battery isolator igniter
T16
16 pin connector, diagnostic port
N738
Wire colours: Diagnostics CAN Dash panel insert CAN Sub-bus system
FlexRay
Input signal
LIN bus
Output signal
Comfort/convenience systems CAN 2
Connection for the front passenger side seat occupancy sensor G128 The connection for the front passenger side seat occupancy sensor G128 varies depending on market version. 1)
In models for the North American Region (NAR): The front passenger side seat occupancy sensor G128 is connected by a discrete line to the seat occupancy recognition control unit J706, which communicates with the airbag control J234 via a LIN bus.
2)
In models for Rest of World (RoW): The front passenger side seat occupancy sensor G128 is connected directly to the airbag control J234 by a discrete line. A seat occupancy recognition control unit J706 is not installed.
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Airbag control unit J234 Installation location
Data bus interface The airbag control unit J234 of the Audi A8 (type 4N) is a further development of the control unit used in the Audi Q7 (type 4M).
Like in the Audi Q7, the control unit communicates via the FlexRay data bus. Due to the increased volume of data in comparison with the Audi Q7, the airbag control unit now communicates with the FlexRay data bus via 2 data lines (channels). These data lines are designated channel "A" and channel "B".
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System overview
Data bus diagnostic interface J533 C h an n e l A
Driver assistance systems control unit J1121
For the sake of clarity, additional system components are only shown on the airbag control unit J234.
Wire colours:
Ch a n ne l B
J1088
J104
J1089
J234
J769
J706
J770
J854
J428
J855
J1122
J1097
J775
J1098
J623
J1019
J792
J500
J217
J527
J187
FlexRay LIN bus Sub-bus system
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Key to figure onpage 58: J104 J187 J217 J234 J428 J500 J527 J623 J706 J769 J770
ABS control unit Differential lock control unit Automatic gearbox control unit Airbag control unit ACC control unit Power steering control unit Steering column electronics control unit Engine control unit Seat occupancy recognition control unit Audi side assist control unit Audi side assist control unit 2
J775 J792 J854 J855 J1019 J1088 J1089 J1097 J1098 J1122
Suspension control unit Active steering control unit Front left seat belt tensioner control unit Front right seat belt tensioner control unit Rear axle steering control unit Control unit for front left radar sensor for object detection Control unit for front right radar sensor for object detection Rear left seat belt tensioner control unit Rear right seat belt tensioner control unit Laser distance measurement control unit
Sensors Like in the Audi Q7 and in the B platform, the driving dynamics control sensors are integrated in the airbag control unit. The driving dynamics control sensors measure acceleration in the X and Y directions as well as the yaw rate about the Z axis. The driving dynamics control sensors work in a lower acceleration and deceleration range than the crash sensors. This acceleration and deceleration levels which can occur during a collision are clearly differ-
ent to those which can occur when a vehicle loses grip (e.g. oversteer, understeer). If the vehicle is equipped with dynamic all-wheel-drive steering or quattro with sport differential, the driving dynamics control sensors are duplicated in the airbag control unit J234. The duplication of the sensors provides sensor signal redundancy (multiple signals).
Centre crash sensor for X/Y axis G858
Installation location
The centre crash sensor for X/Y axis G858 is an acceleration sensor. A combination sensor, the centre sensor for ures both vehicle acceleration andcrash deceleration inX/Y the axis, Y andmeasY directions. The centre crash sensor for X/Y axis is used to validate the plausibility of defined accident events in the longitudinal (X) and transverse directions (Y).
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Crash signal The airbag control unit J234 registers vehicle collisions based on the information supplied by internal and external crash sensors. Depending on the severity of the accident event, the collisions are classified as "minor" or "severe" by the airbag control unit. An accident event classified as minor is again subdivided into several different accident severities.
A severe accident event exists if restraint systems, such as seat belt tensioners and airbags, are deployed. The airbag control unit indicates the accident severity and collision levels to the data bus. Other bus users receive this crash signal and can then take the appropriate action, e.g. shut off fuel supply.
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Action of the 48 V battery in response to a crash signal General If the airbag control unit J234 has detected a relevant crash, the 48-volt battery is deactivated for safety reasons. In the event of an accident, the airbag control unit sends to a collision signal to the data bus. The gateway (data bus diagnostic interface J533) relays this information to the 48 V battery control unit A6 via the hybrid CAN bus. This control unit is located inside the housing of the 48-volt battery. The 48-volt battery isolation igniter N751 is mounted on the control unit PCB. The 48 V battery control unit A6
instructs the battery isolation igniter to disconnect the 48-volt battery. Contrary to what the name might suggest, the batter y isolator igniter does not have a pyrotechnic charge. The igniter in question is a relay. The igniter is an integral part of the 48-volt battery and cannot be replaced separately.
Response to a minor accident As described under "General", the airbag control unit sends a crash signal to the data bus in the event of a minor accident. The battery isolator igniter receives this message and disconnects the 48-volt battery. A 48-volt battery disconnected by a minor accident can be reactivated by a terminal 15 switch-over.
Battery isolation igniter N751 on the PCB of the 48 V battery control unit A6
Response to a severe accident In the event of a severe accident, the signal to isolate the 48-volt battery is transmitted in two different ways. This provides redundant (multiple) backup for signal transmission. > Pathway 1:The 48-volt battery is disconnected as described under "Response to a minor accident". > Pathway 2:The airbag control unit J234 is also wired discretely to the 48 V battery control unit A6. In the event of a severe accident, the airbag control unit energises the battery control unit via the discrete wires by applying a current of about 1.75 to 2 A and instructs the battery isolation igniter to disconnect the 48-volt battery. If a 48-volt battery is disconnected by a severa accident, it can be reactivated with a diagnostic tester and in the Guided Fault Finding function.
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Note The 48-volt battery is not disconnected in the event of a rollover.
Reference For further information about the airbag control unit, the dynamic all-wheel-drive steering and the quattro with sport differential, refer to the following self study programmes: > Dynamic all-wheel-drive steering: Self Study Programm 663 "Audi A8 (type 4N) - Suspension". > quattro with sport differential: Self Study Programm 651 "Audi SQ7 (type 4M)". > Further information about the airbag control unit: Self Study Programme 637 "Audi Q7 (type 4M) Occupant protection and infotainment". > Further information about the 48-volt electrical system: Self Study Programm 664 "Audi A8 (type 4N) - Suspension". 60
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Event Data Recorder (EDR) The Audi A8 (type 4N) comes equipped with an Event Data Recorder (EDR). This system is installed worldwide except in models for the Korean market. The EDR is integrated in the airbag control unit J234 as a software module. The task of the EDR is to record relevant vehicle data over a period of a few seconds in the event of minor accidents or severe accidents and/or near-accident events. The airbag control unit groups minor accidents or severe accidents and/or near-accident events into 2 basic categories. Category 1: A minor accident has occurred if the airbag control unit has detected an accident in which no pyrotechnic components have deployed. A near-accident event is a critical driving situation involving corrective inputs by Audi pre sense and in which no actual accident occurs. Note: The airbag control unit will normally classify a minor parking collision as a minor accident as such an accident has a low severity level. Category 2: A severe accident is a situation in which pyrotechnic components of the restraint systems, e.g. airbags, deploy.
The recorded data is written to a ring memory. This ring memory continuously records the last 5 s of vehicle data while driving. Data which is older than 5 s is either actively cleared again or overwritten by new data. If the airbag control unit detects an accident, the data recorded approximately 5 s before and approximately 300 ms after the accident is transferred to non-erasable read-only memory. This memory has the capacity to record up to 6 accident events. 6 blocks are available in the readonly memory module for this purpose. When the control unit detects severe or minor accidents or nearaccident events, the relevant data is successively written to one of the 6 blocks of the read-only memory. This means that each data packet related to an accident or a near-accident event can be assigned clearly to a block of the memory. A special feature of this system is that a block can be used by data related to a minor accident or a near-accident event, but can be overwritten in the event of a severe accident. In this case, the oldest minor accident or near-accident event is overwritten. At least 2 of the 6 blocks must still be usable. If this is no longer the case, the airbag control unit J234 must be replaced. As minor accidents and near-accident events can be overwritten, they do not necessitate replacing the airbag control unit.
Examples 1. A vehicle has been involved in 6 minor accidents and/or nearaccident events. Each of theseoccurs. situations has been recorded in a block. Now a severe accident The airbag control unit can still be used in this case because the severe accident overwrites the oldest minor accident or near-accident event. The control unit therefore meets the condition that at least 2 of the 6 blocks still have to be usable. Note here that minor accidents and near-accident events can be overwitten by severe accidents.
L1
S1
L2
L2
L3
L3
L4
L4
L5
L5
L6
L6
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2. A vehicle has been involved in 4 severe accidents. Each of these accidents has been recorded in a block. Now a minor accident or near-accident event occurs. The minor accident or near-accident event is recorded in a separate block. The airbag control unit can still be used because a free block is still available and the block in which the minor accident or near-accident event is recorded can be overwritten by a severe accident. Even if 4 severe accidents and 2 minor accidents or near-accident events have been stored in the 6 blocks, the 2 blocks in which the minor accidents or near-accident events are recorded can be overwritten. The control unit therefore meets the condition that at least 2 of the 6 blocks still have to be usable and can still be used.
S1
S1
S2
S2
S3
S3
S4
S4
Free block
L1
Free block
Free block
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3. A vehicle has been involved in 4 severe accidents. Each of these accidents has been recorded in a block. Now another severe accident occurs. The airbag control unit must be replaced after this accident because a further block has been used and, as a result, only 1 block is left. The control unit therefore no longer meets the condition that at least 2 of the 6 blocks still have to be usable.
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S1
S1
S2
S2
S3
S3
S4
S4
Free block
S5
Free block
Free block
Airbag control unit faulty In short, this means that an airbag control unit must be replaced after the 5th accident in which pyrotechnics deploy. In this case, the airbag control until would register the event "fault".
Airbag control unit J234 faulty
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Key: L S Free block
Minor accident or near-accident event Severe accident No accident event
Data recording
As mentioned previously, various units ofdata vehicle data are up recorded. Personal data is not recorded. Generally, is recorded to 5 s before an accident and 300 ms after an accident. This data includes: > Vehicle speed > Engine speed > Steering angle > Seat belt status (fastened/not fastened)
Data is still recordede.g. after the accident. This data includes: > Type of accident, head-on collision/rear-end collision/ rollover > Number of accidents recorded > Whether the accident event recording is complete The data can be used to analyse accident situations and obtain well-founded insights.
Diagnostics and read-out tool The EDR cannot be switched off or deactivated. The data can be read out with a CDR tool (Crash Data Retrieval).
Note Pyrotechnic charges are also ignited in the event of a rollover. For this reason, a rollover also counts as a severe accident. In this generation of control units 4 severe accidents can occur on one side of the vehicle, e.g. 4 head-on collisions, without the control unit having to be replaced. 62
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Assistance system monitor (ASM) Introduction The Audi A8 (type 4N) is, except for models for the Korean market, equipped worldwide with an assistance system monitor. The ASM is integrated in the airbag control unit J234 as a software module. The task of the ASM is to record the data from the driver assistance systems installed in the vehicle over a period of about 10 s before an accident or a near-accident event. The data is written to a ring memory. This ring memory continuously records the last 10 s of vehicle data while driving. Data which is older than 10 s is either actively cleared again or overwritten by new data. If the airbag control unit detects an accident or a near-accident event, the last approx. 10 s of vehicle data before the accident is
transferred to a read-only memory. As with the EDR, the ASM has a read-only memory consisting of 6 blocks. In this case, too, the relevant data is successively written to the blocks after an accident or a near-accident event. Generally, a distinction is made between static and dynamic data, both of which are recorded. Static data indicates whether a driver assistance system is on or off, while dynamic data indicates whether the ESC (Electronic Stability Control) has made corrective inputs or not. The ASM is able to record data from the driver assistance systems, e.g. adaptive cruise assist, ESC (Electronic Stability Control), Audi pre sense and others.
Diagnostics The ASM can be deactivated by service personnel using the "Guided Fault Finding" function. There is a special ASM deactivation form which must be followed and signed by the customer.
Note Both the Audi A3 and the Audi Q2 models are, since week 22/2017, now also equipped worldwide with EDR and ASM. However, there are 2 exceptions: 1. Models for the Korean market 2. Audi A3 models equipped with version "VW20" of the a irbag control unit J234, e.g. vehicles for the Chinese market.
Reference For further information about the EDR and ASM, refer to the owner's manual.
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Active head restraint Introduction Both front seats of the Audi A8 (type 4N) are equipped with active head restraints in combination with PR no. 6C4. The head restraints on the driver side have the designation "driver side active head restraint igniter N419" and the head restraints on the passenger side have the designation "passenger side active head
Ig n i tenr odt e p loy e d
restraint igniter N420". In the event of a rear-end collision which meets the deployment criteria, the active head restraints are ignited. After the igniters deploy, the head restraints move approx. 55 mm forwards and approx. 10 mm upwards.
Ig n i tedr e p lo ye d
6
5
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7
4
11
2
3
12
1 9 10
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8
Installation location
1 2 3 4 5 6
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Active head restraint igniter Bore Pressure chamber Pin Spring sheet Thrust bearings, opposing with jaws (2x)
7 8 9 10 11 12
Locking pin Head restraint Coil spring Carriage guide Locking device Release lever
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Function Head restraint has deployed
Basic position of the head restraint On the opposite side of the thrust bearing (6) there are jaws which apply pressure continuously to the pin (4) through a spring sheet (5). The pin (4) holds the jaws open and the thrust bearings (6), due to their geometry, wrap around the locking pin (7) and lock the head restraint (8) in its starting position.
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Head restraint has deployed
Head restraint has deployed
The igniter for the active head restraint (1) activates the pyrotechnics. The combustion of the propellant charge produces a high pressure, which escapes into the pressure chamber (3) through bores (2). The resultant overpressure in the pressure chamber pushes the pin (4) shown in the illustration to the right. The spring sheet now pushes the jaws together as the pin (4) is no longer in position (displaced). The resulting rotational movement causes the thrust bearings (6) to open and release the locking pin (7), which is securely connected to the head restraint (7). The pretensioning of the coil spring (9) displaces the head restraint along the carriage guide (10) towards the occupant's head. A locking device (11) prevents the head restraint from being pushed back again.
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Resetting the head restraints The active head restraints are reversible. This means that a deployed active head restraint can be reactivated. For this purpose, the release lever (12) must be operated. The lock is cancelled, and the head restraint must be pushed back
until it locks again in the starting position. The active head restraint igniter can no longer be used after it deploys and must be replaced.
Diagnostics
The active head restraints are pyrotechnic components. The safety instructions are the same as for other pyrotechnic components. The airbag control unit J234 continuously monitors the active head restraints for proper functioning. Faults in the system are regis-
tered as event memory entries by the airbag control unit J234. The event memory entries can be cleared using the Guided Fault Finding.
Reference Information on resetting the active head restraint can be found in the Workshop Manual. For information on removal and installation of the driver side active head restraint igniter N419 and the passenger side active head restraint igniter N420, refer to the Workshop Manual and the Guided Fault Finding. 65
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Front passenger airbag OFF warning lamp K145 Since the launch of the Audi Q7 (type 4M), signals are no longer transmitted across discrete wires to the front passenger airbag OFF warning lamp K145. Instead, the signals are transmitted from airbag control unit J234 to the data bus diagnostic interface J533 via the FlexRay data bus. From here, the information is transmitted to the electrical system control unit J519 via the convenience CAN. The electrical system control unit sends information across the LIN bus to the roof electronics control unit J528, which ultimately activates the front passenger airbag OFF warning lamp K145.
The front passenger airbag OFF warning lamp indicates whether the front passenger airbag is on or off.
ON warning lamp
Text indicating the status of the front passenger airbag
OFF warning lamp 662_020
Signal transfer Data bus diagnostic interface J533
Key-operated switch to deactivate front passenger side airbag E224
Airbag control unit J234
Electrical system control unit J519
Roof electronics control unit J528
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Front passenger airbag OFF warning lamp K145
Key: FlexRay Comfort/convenience systems CAN 2
LIN bus
Input signal Output signal
Note This concerns all vehicles which are based on the modular longitudinal platform and which use the FlexRay data bus to communicate with the airbag control unit J234. 66
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Interaction airbag Introduction The Audi A8 (type 4N) is optionally available with front and rear interaction airbags. The interaction airbags deploy in the event of a
side-on collision and can prevent vehicle occupants sitting side by side from colliding with one another.
Front and rear interaction airbags
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Design The interaction airbags are pyrotechnic hybrid gas generators. The "standard" side airbags are generally solid propellant generators. Each interaction airbag is housed in a so-called "hard cover". The internal pressure of the inflated interaction airbags is much higher than that of side airbags. Unlike "standard" side or front airbags, interaction airbags do not have an outlet orifice. Therefore, the excess pressure in the airbag escapes only through the
fabric and through the seams of the airbag. This means that the interaction airbag has a much longer useful life than a side airbag. This is necessary because it has to protect the occupants over a longer period of time. The interaction airbags are activated in all severe side-on impacts in which the side airbags a lso deploy.
Diagnostics The interaction airbags are pyrotechnic components. The safety instructions are the same as for other pyrotechnic components. After ignition, the interaction airbags are unusable and have to be replaced. The airbag control unit J234 continuously monitors the
interaction airbags for proper functioning. Faults in the system are registered as event memory entries by the airbag control unit J234. These faults can be cleared using the "Guided Fault Finding".
Reference For information on installation and removal of the interaction airbags, please refer to the Workshop Manual and the Guided Fault Finding. For further information on the hybrid gas generators and solid propellant generators, refer to Self Study Programme 605 "Audi occupant protection – Passive systems II Audi pre sense". 67
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Front interaction airbag
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Installation location
The front interaction airbag - igniter for interaction airbag for occupant collision protection, driver side N737 - can be ordered with PR no. 6C4. It is integrated in the driver seat backrest. The pressure in the interaction airbag is, in principle, discharged at the same backrest cover seam as the side airbag, but inversely on the other side of the backrest. The interaction airbag is a head-thorax airbag, similar to the side airbags used in convertibles. It can therefore protect both the body and the head of the occupants.
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Rear interaction airbag The rear interaction airbag - igniter for interaction airbag for occupant collision protection, passenge side N738 - can be ordered with PR no. 6C5. If the rear interaction airbag module is installed, the vehicle must be equipped with electrically adjustable individual seats. It is installed in the centre of the parcel shelf between the two rear occupants. The interaction airbag has a cover facing the parcel shelf. The cover forms a unit with the interaction airbag and
Installation location
must not be removed. No objects may be placed on the cover. Otherwise, objects can fly around inside the occupant cell in an uncontrolled way when the interaction airbag deploys. In addition, the interaction airbag may not be able to inflate properly due to these objects. After the rear interaction airbag is installed, the cover is aligned with the parcel shelf and attached to the parcel shelf with clips.
Cover
Electricalconnectorplug
Airbag module 662_026
Note: No objects may be placed on and above the rear interaction airbag cover.
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Automatic belt retractor Front and rear automatic seat belt retractors The front automatic belt retractors are equipped as standard with pyrotechnic belt tensioners, with reversible belt tensioners with electric motors and with active belt force limiters. In combination with PR no. 6C5, the rear outer automatic belt retractors are equipped with pyrotechnic belt tensioners and additionally with reversible belt tensioners with electric motors. The four reversible belt tensioners: > Control unit for front left seat belt tensioner J854 > Control unit for front right seat belt tensioner J855 > Rear left seat belt tensioner control unit J1097 > Rear right seat belt tensioner control unit J1098 are connected to the airbag control unit J234 by a sub-bus system. The seat belt tensioner control units are actuators and are activated by the airbag control unit.
When Audi pre sense basic detects specific driving situations, corresponding signals are sent to the data bus. The airbag control unit evaluates the signals and, if necessary, instructs the seat belt tensioner control unit to partially or fully tension the seat belts via an electric motor. For further information about Audi pre sense, refer to the chapter on "Active safety" onpage 74. If an automatic seat belt retractor with reversible seat belt tensioners is replaced, the basic setting procedure must be performed using the "Guided Fault Finding" function. In this process defined information is written to the airbag control unit. If the basic setting procedure has not been carried out, an entry is made in the event memory of the airbag control unit.
Belt park function (convenience function) The reversible seat belt tensioners are also equipped with a "belt park function". With the belt park function, the seat belt is retracted by the electric motors of the reversible seat belt tensioners. The belt park function is activated when the buckle on a fastened seat belt is opened, and the seat belt is slowly retracted by the automatic retractor. The seat belt may retract slowly at low temperatures or when the retractor mechanism has lost tension.
If movement of the seat belt is detected (occupant still fastened in the vehicle), this time can be extended to a maximum of 20 min. If a reversible seat belt tensioner detects the seat belt retracting in sleep mode, it wakes up the airbag control unit. The airbag control unit can then initiate the retraction of the seat belt by the corresponding belt tensioner control unit. As mentioned previously, the seat belt is only retracted by the electric motors when the seat belt
The seat belt belt has retracts aboutabout 5 s after belt buckle opens or belt if the seat retracted 30%seat relative to the fastened buckle. The belt park function can be activated when the ignition is turned on or off. If the vehicle is already in sleep mode, the reversible seat belt tensioners are active for about 5 s after the seat belt is fastened and monitor the seat belt.
buckle hasseat beenbelt opened and the seat is retracting reversible tensioners have a belt Hall-effect sensorslowly. which The measures the extension of the seat belt based on the rotation of the belt retractor shaft. The seat belt retraction time is determined by the airbag control unit.
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Front reversible belt tensioner Front reversible belt tensioner
If the vehicle is equipped with emergency assist, thedriver's reversible belt tensioner can issue 2 tactile warnings. Both tactile warnings serve to divert the driver's attention back to the traffic situation and to indicate that the driver should continue steering the vehicle. > When a tactile warning is issued, the seat belt is tensioned 3x in quick succession and then released again. This produces a "tug" on the seat belt. > When the other tactile warning is given, the reversible seat belt tensioner is fully tensioned. This eliminates belt slack completely, and the seat belt is tensioned.
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Rear reversible seat tensioner
Rear reversible seat tensioner
In combination with PR no. 6C5, the Audi A8 (type 4N) is equipped with reversible seat tensioners on the rear outer seats in addition to the front reversible seat tensioners.
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Reference For further information about emergency assist, refer to Self Study Programme 668 "Audi A8 (type 4N) Driver assistance systems". For further information about seat belt slack, refer topage 77. 70
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Rear lap belt tensioner Introduction
Installation position
If the Audi A8 (type 4N) is equipped with electrically adjustable individual rear seats (PR no. 3NL/5KF), lap belt tensioners are installed in the rear outer seats. The lap belt tensioners on the driver's side have the designation "seat belt tensioner igniter 2, rear driver side N749" and the lap belt tensioners on the passenger's side have the designation "seat belt tensioner igniter 2, rear passenger side N750". In an accident, if the occupants are wearing their seat belts, the lap belt tensioners have the following effect: > Reduced chest compression > Reduced upper thigh load > Reduced forward displacement of the pelvis > Improved interfacing between the pelvis and seat > Reduced submarining
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Seat belt travel
Accident response sequence In the event of an accident which meets the criteria for deployment, the airbag control unit J234 deploys the belt tensioners and the lap belt tensioners. The seat belt is tensioned by the belt tensioner on the automatic belt retractor. For safety reasons, the belt force is limited by the active belt force limiter. The lap belt tensioner tensions the part of the seat belt in the region of the occupant's pelvis.
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Submarining Submarining occurs if an occupant slides down underneath the lap belt towards the footwell during a head-on collision. This can potentially cause serious injury. The adjustability of the rear seats allows submarining to be reduced depending on seat setting. The
lap belt tensioners counteract submarining by tensioning the lap belts and holding the vehicle occupants in a set position in the seat.
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P os i ti on o f o c cu p a n t b e f o re ac c i d e n t
O c c u p a n t b e g i n s t o s li d e d o w n w a r d
O c c u p a n t s l i d e s d o w n u n d e r n e a t h t h e s e a t b e lt
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Installation location The lap belt te nsioner is engaged and bolted to the rear bulkhead at the rear left and right.
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Coupling The seat belt is diverted at the seat belt end fitting in the seat frame area and, unlike in other vehicles, is movable without lap belt tensioners. A coupling is stitched to the end of the seat belt. The lap belt tensioner coupling is inserted into the seat belt coupling and clipped into place.
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Diagnostics The lap belt te nsioner is a pyrotechnic component. The safety instructions are the same as for other pyrotechnic components. The lap belt te nsioner becomes unusable after its pyrotechnic charge has ignited and has to be replaced as a unit. The airbag
control unit J234 continuously monitors the lap belt tensioners for proper functioning. Faults in the system are registered as event memory entries by the airbag control unit J234. These faults can be cleared using the "Guided Fault Finding".
Buckle The layout of the seat belt end fitting and the coupling point means that no additional buckle is required at the seat belt tensioner in the Audi A8 (type 4N).
Reference The basic working principle of a lap belt tensioner is explained in Self Study Programme 625 "Audi A3 saloon".
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Illuminated seat belt buckles Introduction The Audi A8 (type 4N) is optionally available with illuminated seat belt buckles. Illuminated seat belt buckles help the vehicle occupants to locate their seat belt buckle in the dark. The PR no. 6C5 for the illuminated seat belt buckles is part of the Plus safety package. The illuminated seat belt buckles are fitted at the front and rear on the driver and front passenger sides. The electrical system control unit J519 is responsible for the illumination of the seat belt buckles. For this reason, the electrical system control unit is wired to the seat belt buckle lighting units. For further information
about the illumination function of the seat belt buckles (e.g. switch-on point, run-on time etc.), please refer to page 49 of Self Study Programme 664 "Audi A8 (type 4N) - Electrics and electronics". The actual seat belt function is unchanged. This means that the seat belt buckles are still a component part of the occupant protection system and are wired to the airbag control unit J234. The electrical seat belt buckles use 4 pins instead of 2 lighting due to the fact that they are illuminated.
Design of the lighting unit The design of the lighting unit is based on the components listed below.
LED unit with housing
Optical fibre
Luminous ring
Cap
Seat belt buckle
Cable with 4-pin plug
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Reference The basic design of the seat belt buckles is explained in Self Study Programme 410 "Audi occupant protection – Passive systems". 73
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Active safety Audi pre sense Working within its system limitations, Audi pre sense is able to initiate actions to protect the occupants and other road users in certain critical situations. For this purpose, the vehicle and its occupants are prepared for a potentially imminent collision. This is made possible by the connectivity of the various in-car systems. The systems send data continuously to the data bus. Other control units are able to evaluate this information and take appropriate action. Depending on the Audi pre sense package (rear, side, front, evasion assist and turn-off assist), trucks, passenger cars, motorcycles, bicycles and pedestrians can be detected. Please note that Audi pre sense cannot prevent collisions. It serves only to assist the driver and it can reduce the severity of the collision.
It should also be noted that not all objects or lane makings can be detected by the sensor or by the camera. The following Audi pre sense functions are available for the Audi A8 (type 4N).
Audi pre sense basic
PR no. 7W1
Audi pre sense side
PR no. JX1+7Y1
Audi pre sense front1)
PR no. 6K8
Audi pre sense rear inclusive of pre sense basic
PR no. 7W3
Audi pre sense turn-o assist
PR no. 8T3 / 8T8
Audi pre sense evasion assist
PR no. 8T3 / 8T8
Airbag control unit The airbag control unit J234 has been modified extensively with
In consequence of the above-mentioned modifications, the various
regard Audi sense. These modifications meanwhich that the airbag controlto unit canpre now initiate Audi pre sense actions were previously initiated by other control units. For example, the front camera for driver assistance systems R242 in the Audi Q7 (type 4M) evaluates the "image data" which it has acquired. Depending on the severity of the critical situation, the front camera then instructs other systems to initiate actions. Such actions can include an acute warning (brake warning) or automatic and/or assistive braking by the ABS control unit J104. The ACC control unit and the side assist control units behave similarly. These control units also register and evaluate driving situations. If necessary, they can instruct other systems to initiate actions, depending on the driving situation.
control units now send theirunit driving situation data to the(data) driveris assistance systems control J1121. This information collated in the driver assistance systems control unit. This merging of information (data) from different sources is termed "data fusion". The advantage of data fusion is that it provides a comprehensive picture of the vehicle periphery. The driver assistance systems control unit sends this data via the bus systems to recipients such as the airbag control unit. The airbag control unit evaluates this data and can instruct other systems to initiate actions appropriate to the situation. The individual functions of Audi pre sense are described in greater detail below.
Note 1) A further Audi pre sense front function will be introduced at a later date.
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Audi pre sense settings Setting and switching off the early warning The early warning function of Audi pre sense front can be set and deactivated in the MMI. The following setting options are available: off The audible and visual early warning function is off. early The audible and visual early warnings are set to earlier. medium The visual and audible early warnings are included here in the basic setting. late The audible and visual early warnings are set to later.
> The settings for the "early", "medium" or "late" early warning are active until another selection is made in the MMI. > If the early warning has been set to "off", the early warning is switched on again after the ignition is turned back on1). The system reactivates the setting which was active before the early warning was switched off.
Car Individual profile Information on Audi pre sense Early warning Turn-off assist Evasion assist
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Car Individual profile off early medium late
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1)
Not available in all countries. 75
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Switching off off Audi pre sense Audi pre sense can be switched off in the MMI. All functions of Audi pre sense front, side, rear as well as evasion assist and turnoff assist are deactivated. When Audi pre sense is switched off, the partial tensioning of the reversible seat belt tensioners by Audi pre sense basic is deactivated. The full tensioning function remains active.
Car · Driver assist
Traffic light information Adaptive cruise assist Distance warning Audi pre sense Active lane departure warning
Activating Audi pre sense
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If Audi pre sense is off, it can be reactivated in the MMI. Here, all functions of Audi pre sense are reactivated. When the ignition is turned off and on again, Audi pre sense, if off, is reactivated automatically1).
Turn-off assist / evasion assist The turn-off assist and evasion assist functions of Audi pre sense can be switched off separately in the MMI. Once they have been switched off, turn-off assist and evasion assist remain switched off until the functions are reactivated in the MMI. Switching the ignition off and on again does not activate the turn-off assist and evasion assist functions.
Audi pre sense and profile master for driver assistance systems Audi pre sense can also be switched off in the profile master for driver assistance systems under "Individual". All functions of Audi pre sense front, side, rear as well a s evasion assist and turnoff assist are deactivated. In this case, the partial tensioning of the reversible seat belt tensioners is also switched off. The full tensioning of the reversible seat belt tensioners is not switched off and
remains active. Once it has been switched off, Audi pre sense remains switched off until it is reactivated in the profile master for driver assistance systems. When the ignition is turned off and on again, Audi pre sense, if switched off in the profile master for 1) driver assistance systems, is reactivated automatically .
Profile master for driver assistance systems
Audi pre sense off
Car · Driver assist
Car · Individual profile
Night vision assist Distance warning
Basic Maximum
Audi pre sense Side assist
Indivual
Intersection assist 662_125
1)
Not available in all countries.
Reference For further information about the profile master for driver assistance systems, refer to Self Study Programme 668 "Audi A8 (type 4N) Driver assistance systems." 76
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Pre sense basic Reversible belt tensioners If the Audi A8 (type 4N) is equipped with the PR no. 6C5, the rear outer seats are equipped with reversible seat belt tensioners2) in addition to the front reversible seat belt tensioners. The functions of the front and rear reversible seat belt tensioners are identical. The following information therefore refers to both the front and rear reversible seat belt tensioners.
With Audi pre sense basic, the following actions can be taken: > Belt slack reduction > Partial tensioning of the electrically reversible seat belt tensioners > Full tensioning of the electrically reversible seat belt tensioners > Closing of the panoramic glass sunroof2) > Closing of the side windows apart from a residual gap > Inflation of the side bolsters in the seats and backrests2). > Activation of the hazard warning flashers1) > Display of corrective action by Audi pre sense in the instrument cluster
Definition and function of the belt slack reduction system for reversible seat belt tensioners In certain situations, e.g. when wearing a thick winter jacket, it may be the case that after fastening the seat belt with reversible seat belt tensioners the seat belt does not tight against the body. In such a case, the wind-up force of the automatic seat belt retractor is less than the force required to compress the thick winter jacket. The distance which the seat belt can travel until it fits the front occupants perfectly is termed "belt slack".
The seat belt is unreeled with defined force by the reversible seat belt tensioners under the following conditions. This enables any existing belt slack to be reduced. > If the vehicle reaches a speed of about 15 kph after starting the engine and travelling forwards. > If the vehicle has not reached a speed of 15 kph about 10 s after starting the engine and travelling forwards.
Seat belt fitting tightly (low belt slack)
Seat belt on "thick" clothing (greater belt slack)
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1) 2)
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System characteristics of the reversible seat belt tensioners > After reducing seat belt slack, the seat belt is released again. > If a seat belt is not worn, the slack is not reduced for this seat belt. > The 4 reversible seat belt tensioners: > Control unit for front left seat belt tensioner J854 > Control unit for front right seat belt tensioner J855 > Rear left seat belt tensioner control unit J10972) > Rear right seat belt tensioner control unit J10982), are connected to the airbag control unit J234 via a sub-bus system. The airbag control unit instructs the seat belt tensioners to reduce the belt slack.
Tensioning of the reversible seat belt tensioners In the case of Audi pre sense basic, tensioning of the reversible seat belt tensioners can be carried out at a speed of higher than 30 kph when the longitudinal and transverse dynamics functions are active. To activate longitudinal dynamics, the vehicle must be moving forwards. An exception here is the crash function in the low relative speed range (refer topage 81).
Longitudinal dynamics function Hazard braking If the brake pressure reaches a defined value during a hazard braking manoeuvre, Audi pre se nse basic initiates electricalp artial tensioningof the reversible seat belt tensioners.
A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given.
Emergency braking During an emergency braking manoeuvre, the reversible seat belt tensioners are fully tensioned . Depending on the situation, the ABS control unit J104 can instruct the hazard warning flashers1) to be activated. A distinction is made between the following 3 criteria for emergency braking. > An emergency braking situation exists if the ABS control unit J104 detects that brake pressure had reached a specific value within a defined period of time. If the conditions are met, Audi pre sense basic initiates electricalfull tensioningof the reversible seat belt tensioners. A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given. > An emergency braking situation exists if the given conditions are not met, but if the ABS control unit J104 has detected an emergency braking manoeuvre based on the pedal rates. If the conditions are met, Audi pre sense basic initiates electricalf ull tensioningof the reversible seat belt tensioners. A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given.
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Not available in all countries. Optional equipment.
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> An emergency braking maneouvre also exists if the electromechanical brake is applied when travelling forwards at a speed of approx. 30 kph or higher. Audi pre sense basic then initiates the full tensioning of the reversible seat belt tensioners. In this case, no Audi pre sense message appears in the instrument cluster. The seat belts are released again under the following conditions: > When the electromechanical parking brake button is released. > When the vehicle comes to a standstill. > When the driver presses his foot down heavily on the accelerator and thus overrides the emergency braking of the electromechanical parking brake.
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Process diagram of the Audi pre sense basic longitudinal dynamics function
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Key:
Belt slack reduction
Visual advance warning and/or indication of corrective action
Partialtensioning
Fulltensioning
System characteristics of the longitudinal dynamics function > If Electronic Stability Control (ESC) is set to "sport" or "off" using the TCS/ESP button E256, the seat belts arenot partially tensioned. > If Audi drive select is set to "dynamic", the seat belts arenot partially tensioned . > If Audi pre sense is deactivated in the MMI, the seat belts are not partially tensioned either.
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Drive profile selection switch module E592
TCS/ESP button E256
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Transverse dynamics function If the vehicle oversteers or understeers, the Electronic Stability Control (ESC) will try to stabilise the vehicle. If the vehicle becomes unstable because certain physical limits have been exceeded, the airbag control unit J234 initiatespartial tensioning of the electrically reversible seat belt tensioners. A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given.
If the vehicle can no longer be stabilised, the following actions are initiated:
> The electrically reversible seat belt tensioners are fully tensioned. A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given. > The side bolsters of the seats and backrests are inflated when the seat belts are fully and partially tensioned2). > The side windows and the panoramic glass sunroof2) are closed when the seat belts are fully and partially tensioned. > As long as the vehicle is unstable, the hazard warning flashers1) Process diagram of the Audi pre sense basic transverse dynamics are switched on for up to 15 s when the seat belts are fully and function partially tensioned.
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Key:
Belt slack reduction
Visual advance warning and/or indication of corrective action
Partial tensioning
Full tensioning
Inflation of the seat side bolsters
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Hazard warning lights
System characteristics of the transverse dynamics function > If Audi drive select is set to "dynamic", the seat belts arenot partially tensioned . > If Audi pre sense is deactivated in the MMI, the seat belts are not partially tensioned either.
> If the vehicle is unstable, Electronic Stability Control is set to "sport" or "off" and the driver actively a pplies the brakes, the seat belts are fully tensioned . A message indicating that Audi pre sense is active appears in the instrument cluster. No audible signal is given. The side windows and the panoramic glass sunroof2) are closed. As long as the vehicle is unstable, the hazard warning flashers1) are switched on for up to 15 s when the seat belts are fully and partially tensioned.
Note In case of vehicle instability, a time limit on the hazard warning flashers is implemented in all vehicles in which the airbag control unit J234 is connected to the FlexRay data bus. 80
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Crash function in the low relative speed range If the airbag control unit J234 detects a head-on collision at a low relative speed3) and at a low rate of vehicle deceleration, the airbag control unit decides situationally on the basis of the control unit algorithm whether to initiate electricalfull tensioning .
A condition is that no pyrotechnic components, such as the airbags, deploy during these head-on collisions. In addition to this, the closing of the side windows and the panoramic glass sunroof2) as welll as the inflation of the seat and backrest side bolsters2) are initiated at speeds of 50 kph or higher. The hazard warning flashers are not switched on.
Pre sense rear With Audi pre sense rear, the following actions can be initiated: > RECAS alert (Rear End Collision Avoidance System)1). > The electrical upper backrests2) move into an upright position. > The electrical head restraints2) move into an elevated position. > Inflation of the side bolsters in the seats and backrests2). > Closing the panoramic glass sunroof2). > Closing of the side windows apart from a residual gap. > Speed-dependent partial or full tensioning of the electrically reversible seat belt tensioners. > Display of corrective action by Audi pre sense in the instrument cluster.
Overview of the radar sensors
Installation location Audi pre sense rear is only possible if the vehicle has Audi side assist. Audi side ass ist utilises 2 "mid-range" radar sensors which are able to detect objects within a distance of about 0 to 70 m behind the vehicle. The Audi side assist control unit J769 is installed in the rear bumper on the right-hand side in of the vehicle. The Audi side assist control unit 2 J770 is installed the rear bumper on the left-hand side of the vehicle. Each control unit combines with a radar sensor to form a unit. Audi pre sense rear utilises the control units including the radar sensors of Audi side assist.
Audi side assist control unit 2 J770
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Lane change assist control unit J769 is installed analogously on the right-hand side of the vehicle. 662_091 1)
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Function The radar sensors continuously monitor the traffic following the vehicle whenever Audi side assist is inactive. Control units J769 and J770 send signals they receive as data to the airbag control unit J234 via FlexRay data bus (channel "B"). The information supplied by the ABS control unit J104 tells vehicle how fast it is travelling. The airbag control unit calculates the speeds of the following vehicles on the basis of this information. The following information is therefore available to Audi pre sense rear4): > Distance of following vehicles. > Speed of following vehicles. > Speed of own vehicle.
A critical situation is defined as a situation in which a following vehicle would collide with the rear end of one's own vehicle unless further action is taken by the driver of the following vehicle. Taking the available information as a basis, the airbag control unit decides which actuators to activate. It relays this information to different control units such as the sliding sunroof control unit J2452). The other control units receive this data and activate the relevant actuators.
Audi pre sense rear now initiates the following actions, which can be subdivided into two phases.
RECAS warning
Phase 1 1. Initially, the indicators flash rapidly for about 3 s1). This flashing cycle is known as a RECAS alert, RECAS being the abbreviation for Rear End Collision Avoidance System. Due to the high frequency at which the indicators are activated, humans see these signals as flashes of light. The flashing of the indicators alerts the drivers in following vehicles to a critical situation ahead and animates them to take appropriate action, e.g. initiate braking. The time of activation of the RECAS alert depends on the severity of the critical situation and the relative speed3) of the following vehicles. The electrical system control unit J519 activates the RECAS alert. 2. If the driver in the following vehicle reacts during this phase, e.g. brakes or takes evasive action, and Audi lane assist control units J769 and J770 no longer detect a critical situation, then no further action, e.g. closing of the side windows, is taken.
Phase 2
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Audi pre sense rear
1. If the critical situation still exists, the side windows and the panoramic glass sunroof2) are closed. If installed, the electrical head restraints2) on the seats move upward and the electrical upper backrests2) (seat adjustment) move forward. If the vehicle is equipped with pneumatic seats2), the seat and backrest side bolsters are inflated.
1)
Not available in all countries. Optional equipment. 3) The relative speed is the difference in speed between one's own vehicle and the other vehicle involved in the rear-end collision. 4) A precondition is that the following vehicles are within the detection range of the radar sensors. 2)
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2. Approximately 1 second after the side windows, the panoramic glass sunroof2), the seat adjustment2) and the side bolsters2) are activated, the instrument cluster indicates that Audi pre sense is active.
Audi pre sense display
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3. If the vehicle continues to approach and the danger of a rearend collision increases, the reversible seat belt tensioners are partially and fully tensioned depending on how fast one's own
The reversible seat belt tensioners are: > Control unit for front left seat belt tensioner J854 > Control unit for front right seat belt tensioner J855 2)
vehicle travelling.ifThe seat belt tensioners partiallyistensioned thereversible vehicle is travelling at a higherare speed and fully tensioned if the vehicle is travelling at a lower speed. If one's own vehicle exceeds a preset speed, reversible seat belt tensioners are not tensioned. The 4 reversible seat belt tensioners are connected to the airbag control unit J234 by a sub-bus system.
> > Rear Rear left rightseat seatbelt belttensioner tensionercontrol controlunit unitJ1097 J10982)
System characteristics of Audi pre sense rear > If a trailer is detected coupled to the vehicle via a factory fitted tow bar, Audi pre sense rear is not active.
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Process diagram of Audi pre sense rear
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Key:
RECAS alert
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Movement of the electrical head restraints into the upright position
Movement of the upper backrests into the upright position
Inflation of the seat side bolsters
Visual advance warning and/or indication of corrective action
Partialtensioning
Fulltensioning
Pre sense side Audi pre sense side can initiate measures for the protection of the vehicle occupants in the event of a side-on collision with another vehicle. Audi pre sense side will be introduced at a future date. In models equipped with Audi pre sense side, the following actions can be initiated: > Raising2) of the vehicle in the event of an imminent side-on impact on the collision-facing side. In this way, the forces occurring during a collision can be redirected toward crash-
> The electrical upper backrests2) move into an upright position. > The electrical head restraints2) move into an elevated position. > The doors are locked (to be implemented at a future date). 1)
active body structures. > Full tensioning of the electrically reversible seat belt tensioners. > Closing of the side windows apart from a residual gap. > Closing the panoramic glass sunroof2).
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Not available in all countries. Optional equipment.
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> Activation of the hazard warning flashers . > Display of corrective action by Audi pre sense in the instrument cluster.
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Installation location Audi pre sense side is only possible if the vehicle is equipped with Audi side assist and intersection assist. Audi side assist utilises 2 "mid-range" radar sensors which are able to detect objects within a distance of 0 – 70 m behind and to the side of one's own vehicle. The Audi side assist control unit J769 is installed in the rear bumper on the right-hand side of the vehicle. The Audi side assist control unit 2 J770 is installed in the rear bumper on the left-hand side of the vehicle. Intesection assist also utilises 2 "mid-range" radar sensors which are able to detect objects within a distance of 0 – 70 m behind and to the side of one's own vehicle. The control unit for front left radar sensor for object detection J1088 is
installed in the front bumper on the left-hand side of the vehicle. The control unit for front right radar sensor for object detection J1089 is installed in the front bumper on the right-hand side of the vehicle. Each of these 4 control units combines with a radar sensor to form a unit. The radar beam angle of the radar sensors is approx. 150°. Audi pre sense side utilises the control units including the radar sensors of Audi side assist and the intersection assist system for the purposes of object recognition.
Overview of the corner radar sensors
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Control unit for front left radar sensor for object detection J1088
Audi side assist control unit 2 J770
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The control unit for front radar sensor for object detection J1089 and the rear side assist control unit J769 are installed analogously on the right-hand side of the vehicle.
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Function The 4 radar sensors continuously monitor the traffic to the side of as well as in front of and behind one's own vehicle, even when Audi side assist and intersection assist are inactive. The signals recorded by the radar sensors are sent to the driver assistance systems control unit J1121 as data. The driver assistance s ystems control unit merges the data so that an exact map the vehicle periphery can be obtained and evaluated. If critical objects are detected on either side of one's own vehicle, this information is sent to the airbag control unit J234. The airbag control unit evaluates the data and can instruct other systems to initiate actions appropriate to the situation. In the case of Audi pre sense side, a critical situation is when a vehicle approaching from the side will, with a high degree of probability, collide sideways with one's own vehicle.
If the airbag control unit detects a critical situation, it takes the following measures almost simultaneously: > Raising2) of the vehicle on the collision-facing side (to be implemented at a future date). > Full tensioning of the reversible seat belt tensioners. > Closing of the side windows apart from a residual gap. > Closing of the panoramic glass sunroof2). > The electrical upper backrests2) move into an upright position. > The electrical head restraints2) move into an elevated position. > Locking of the doors. > Activation of the hazard warning flashers1). > In addition, a visual message indicating that Audi pre sense is active appears in the instrument cluster.
Process diagram of Audi pre sense side
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Key: Visual advance warning and/or indication of corrective action Closing of the side windows apart from a residual gap
Hazard warning lights
1) 2)
Not available in all countries. Optional equipment.
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Raising of the vehicle on the collision-facing side
Full tensioning
Closing the panoramic glass sunroof
Locking of the doors
Movement of the upper backrests into the upright position
Movement of the electrical head restraints into the upright position
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System characteristics of Audi pre sense side > Audi pre sense side is available while travelling forward at speeds of between about 0 and 60 kph. It is also available at speeds of between about 0 and 20 kph while reversing.
> To be able to detect vehicles from the side, these vehicles must be approaching one's own vehicle from the side at below a defined angle.
Note: To avoid the danger a vehicle being raised automatically while working on the vehicle, refer to the safety instructions for deactivating the vehicle raise function in the Workshop Manual.
Pre sense front Audi pre sense front can, in the event of possible head-on collisions, assist the driver different by taking a variety of measures. In models equipped with Audi pre sense front, the following action can be taken: > > > > > > > >
Visual prewarning. Audible prewarning. Prefilling of the brake system. Reconfiguration of hydraulic brake assist. Acute warning by braking impulse. Automatic braking to emergency braking level. Target braking. The electrical head restraints2) move into an elevated position.
Inflation of the side bolsters in the seats and backrests2). Closing the panoramic glass sunroof2). Closing of the side windows apart from a residual gap. Partial tensioning of the electrically reversible seat belt tensioners. > Full tensioning of the electrically reversible seat belt tensioners. > Display of corrective action by Audi pre sense in the instrument cluster. > Driver take-over prompt. > > > >
Installation location
To Audi sense front, the vehicleR242. requires: > implement Front camera forpre driver assistance systems
Front camera for driver assistance systems R242
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Optional equipment.
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Function The front camera for driver a ssistance systems R242 continuously monitors the traffic in front of one's own vehicle. The resulting signals are sent to the driver assistance systems control unit J1121 as data. The driver assistance systems control unit sends the data to the airbag control unit J234. The airbag control unit evaluates the data and can instruct other systems to initiate actions appropriate to the situation.
The system can, under certain conditions, detect the following scenarios: > Vehicles in front of one's own vehicle (passenger cars, trucks, motorcycles) > Cyclists in the same lane in the same lane as the vehicle or moving into the same lane as the vehicle. > Pedestrians in the same lane as the vehicle or moving into same lane as the vehicle.
Response to vehicles The following preconditions must be met in order to activate the system: > Audi pre sense front is able to respond to vehicles which are travelling in the same direction and which have stopped or are stationary. > Audi pre sense front does not respond to crossing or oncoming traffic. > Audi pre sense front is active at a speed of approx. 10 kph or higher.
> Audi pre sense front can warn against vehicles up to a speed of 250 kph. > Audi pre sense front can initiate braking up to a speed of 250 kph.
Advance warning phase If the vehicle approaches another vehicle which is travelling in the same direction at speeds of between about 30 and 250 kph resulting in a critical driving situation, the instrument cluster gives the driver audible and visual early warnings when set limits are
pedal and turn signal inputs, the system classifies the driver as active or inactive and, consequently, as attentive or inattentive. If the driver is deemed to be "attentive", warnings are issued later than for a driver deemed to be "inattentive". At the same time, the
exceeded. These are given within a certain time frame ahead of the last warnings braking opportunity for braking or collision avoidance before the actual collision occurs. The timing of warnings depends on the driver's activity level. Depending on steering,
ABS control unitassist J104 initiates prefilling of the brake and hydraulic brake is reconfigured. Hydraulic brakesystem, assist reacts more sensitively to pedal operations by the driver.
Acute warning phase If driver does not respond to the warnings, however, the ABS control unit J104 generates an acute warning by initiating a brake warning. At the same time, a visual warning is issued via the instrument cluster display. The brake warning is a very brief but easily noticeable braking impulse which does not slow the vehicle down directly. It alerts the driver to the traffic situation and
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indicates to the driver that he must react immediately in order to prevent an impending collision. Depending on how attentive the driver is deemed to be, the brake warning is produced within a certain time window ahead of the last opportunity to brake or take evasive action in order to avoid a collision.
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Automatic brake intervention phase If the driver fails to respond to the brake warning or only takes his foot off the accelerator, the ABS control unit J104 initiates automatic braking1). Depending on the speed at which the vehicle is travelling, braking power may increase progressively to maximum level (emergency braking). Depending on the situation, the ABS control unit J104 can instruct the hazard warning flashers1) to be activated. Depending on the situation, the following additional actions may be initiated: > The electrical head restraints2) move into an elevated position. > Inflation of the side bolsters in the seats and backrests2). > Closing the panoramic glass sunroof2). > Closing of the side windows apart from a residual gap. > Partial tensioning of the electrically reversible seat belt tensioners > Full tensioning of the electrically reversible seat belt tensioners. > Display of corrective action by Audi pre sense in the instrument cluster.
If the vehicle automatically brakes itself to a standstill without driver intervention, a driver take-over prompt appears in the instrument cluster and further audible signals sound. These signals will alert the driver to the fact that he must actively take control of the vehicle (e.g. by applying braking). If the driver fails to take control of the vehicle, the system will release the brake and the vehicle will start to move.
Process diagram showing how Audi Pre sense front responds automatically to vehicles
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Key:
1) 2)
Visual advance warning and/or indication of corrective action
Audible warning beep
Reconfiguration of
Acute warning by braking
hydraulic brake assist
impulse
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Partial tensioning
Full tensioning
Inflation of the seat side bolsters
Movement of the upper backrests into the upright position
Movement of the electrical head restraints into the upright position
Driver take-over prompt
Prefilling of the brake system Automatic braking up to emergency braking intensity
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Assistive brake intervention phase When the driver applies the brakes a target braking maneouvre can be performed in all of the phases described above (prefilling of the brake system, reconfiguration of hydraulic brake assist, prewarning, acute warning, automatic braking). During the target braking manoeuvre the Audi pre sense front system calculates whether the driver has applied sufficient braking to be able to prevent a collision. If this is not the case, the required amount of braking is increased (up to maximum level depending on the situation). Depending on the situation, the ABS control unit J104 can instruct the hazard warning flashers1) to be activated. Depending on the situation, the following additional actions may be initiated: > The electrical head restraints2) move into an elevated position. > Inflation of the side bolsters in the seats and backrests2). > Closing the panoramic glass sunroof2). > Closing of the side windows apart from a residual gap. > Partial tensioning of the electrically reversible seat belt tensioners > Full tensioning of the electrically reversible seat belt tensioners. > Display of corrective action by Audi pre sense in the instrument cluster
If the vehicle has assistively braked itself to a standstill without driver intervention, a driver take-over prompt appears in the instrument cluster and further audible signals sound. These signals will alert the driver to the fact that he must actively take control of the vehicle (e.g. by applying braking). If the driver fails to take control of the vehicle, the system will release the brake and the vehicle will start to move.
Process diagram showing how Audi Pre sense front responds assisitively to vehicles
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Key: Visual advance warning and/or indication of cor-
Audible warning beep
Prefilling of the brake system
Reconfiguration of hydraulic brake assist
Acute warning by braking impulse
Target braking
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Partial tensioning
Full tensioning
Inflation of the seat side bolsters
Movement of the upper backrests into the upright position
Movement of the electrical head restraints into the upright position
Driver take-over prompt
rective action
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Response to pedestrian or cyclist The following preconditions must be met in order to activate the system: > Audi pre sense city responds to pedestrians and cyclists in the same lane as the vehicle or moving into the same lane as the vehicle. > Audi pre sense front is active at a speed of approx. 10 kph or higher.
> Audi pre sense front can warn against pedestrians and cyclists up to a speed of 85 kph. > Audi pre sense front can initiate braking up to a speed of 85 kph.
Advance warning phase If the vehicle is travelling at speeds of between about 10 and 85 kph and a pedestrian or cyclist is in the same lane as the vehicle or moving into the same lane as the vehicle resulting in a crtitical driving situation, the instrument cluster alerts the driver by issuing audible and visual warnings. These warnings are given within a certain time frame ahead of the last braking opportunity for braking or collision avoidance before the actual collision occurs. The timing of warnings depends on the driver's activity level.
Depending on steering, pedal and turn signal inputs, the system classifies the driver as active or inactive and, consequently, as attentive or inattentive. If the driver is deemed to be "attentive", warnings are issued later than for a driver deemed to be "inattentive". At the same time, the ABS control unit J104 initiates prefilling of the brake system, and hydraulic brake assist is reconfigured. Hydraulic brake assist reacts more sensitively to pedal operations by the driver.
Acute warning phase If driver does not respond to the warnings, however, the ABS control unit J104 generates an acute warning by initiating a brake warning. At the same time, a visual warning is issued via the instrument cluster display. The brake warning is a very brief but
indicates to the driver that he must react immediately in order to prevent an impending collision. Depending on how attentive the driver is deemed to be, the brake warning is produced within a certain time window ahead of the last opportunity to brake or take
easily noticeable braking which does not slow the vehicle down directly. It alerts theimpulse driver to the traffic situation and
evasive action in order to avoid a collision.
Automatic brake intervention phase If the driver fails to respond to the brake warning or only takes his foot off the accelerator, the ABS control unit J104 initiates automatic braking1). Depending on the speed at which the vehicle is travelling, braking power may increase progressively to maximum level (emergency braking). Depending on the situation, the ABS control unit J104 can instruct the hazard warning flashers1) to be activated. Depending on the situation, the following additional actions may be initiated: > Closing the panoramic glass sunroof2). > Closing of the side windows apart from a residual gap.
If the vehicle automatically brakes itself to a standstill without driver intervention, a driver take-over prompt appears in the instrument cluster and further audible signals sound. These signals will alert the driver to the fact that he must actively take control of the vehicle (e.g. by applying braking). If the driver fails to take control of the vehicle, the system will release the brake and the vehicle will start to move.
> Partial tensioning of the electrically reversible seat belt tensioners > Display of corrective action by Audi pre sense in the instrument cluster.
1) 2)
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Process diagram showing how Audi Pre sense front responds automatically to pedestrians/cyclists
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Key: Visual advance warning and/or indication of corrective action
Audible warning beep
Prefilling of the brake system
Reconfiguration of hydraulic brake assist
Acute warning by braking impulse
Automatic braking up to emergency braking intensity
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Partial tensioning
Driver take-over prompt
Assistive brake intervention phase When the driver applies the brakes a target braking maneouvre can be performed in all of the phases described above (prefilling of the brake system, reconfiguration of hydraulic brake assist, prewarning, acute warning, automatic braking). During the target braking manoeuvre the Audi pre sense front system calculates whether the driver has applied sufficient braking to be able to prevent a colli-
If the vehicle has assistively braked itself to a standstill without driver intervention, a driver take-over prompt appears in the instrument cluster and further audible signals sound. These signals will alert the driver to the fact that he must actively take control of the vehicle (e.g. by applying braking). If the driver fails to take control of the vehicle, the system will release the brake and the vehicle will
sion. If this is not the case, the required amount of braking is increased (up to maximum level depending on the situation). Depending on the situation, the ABS control unit J104 can instruct the hazard warning flashers1) to be activated. Depending on the situation, the following additional actions may be initiated: > Closing the panoramic glass sunroof2). > Closing of the side windows apart from a residual gap. > Partial tensioning of the electrically reversible seat belt te nsioners > Display of corrective action by Audi pre sense in the instrument cluster
start to move.
1) 2)
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Process diagram showing how Audi Pre sense front responds assistively to pedestrians/cyclists
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Key: Visual advance warning and/or indication of corrective action
Audible warning beep
Prefilling of the brake system
Reconfiguration of hydraulic brake assist
Acute warning by braking impulse
Target braking
Closing of the side windows apart from a residual gap
Closing the panoramic glass sunroof
Partial tensioning
Driver take-over prompt
System characteristics of Audi pre sense front > In towing mode, the braking behaviour of the vehicle/trailer combination may be different to what one is used to, due to the increase in mass and the effect this has on braking and stabilisation behaviour under automatic braking. > If an emergency braking manoeuvre is initiated by the vehicle, Audi pre sense city can help reduce the vehicle's speed by up to 60 kph. > Depending on the situation, the ABS control unit J104 can
> If ESC is set to "off", certain functions of Audi pre sense front will only be available to a limited extent or will be unavailable. > If the functionality of the front camera for driver assistance systems R242 is impaired due to bad visibility and light conditions such as darkness or fog, Audi pre sense front will only be available to a limited extent or will be unavailable. > If driver is not wearing a se at belt, certain functions of Audi pre sense front will only be available to a limited extent or
instruct the hazard warning flashers (emergency braking warning) 1) to be activated. > If the driver takes clear evasive action or applies the brakes during the collision warning or corrective braking phases of an Audi pre sense front action, the current actions of Audi pre sense front (e. g. early warning) will be suppressed or cancelled. If the obstacle is no longer relevant after this, Audi pre sense front will cease to provide driver assistance. > If Audi pre sense is deactivated in the MMI, the warning and braking functions of Audi pre sense front will be deactivated, too.
will be unavailable. > The front camera for driver assist systems self-initialises after the ignition is switched on. It may, therefore, be the case that Audi pre sense front is not available for up to 20 s after turning on the ignition. The non-availability Audi pre sense front is indicated by the initialisation lamp.
Note A further version of Audi pre sense front will be introduced at a future date.
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Pre sense turn-off assist Audi pre sense turn-off assist can help the driver with turn-off manoeuvres. In models equipped with Audi pre sense turn-off assist, the following actions can be taken: > Reconfiguration of hydraulic brake assist. > Automatic emergency braking1). > Display of corrective action by Audi pre sense in the instrument cluster (visual and audible)
Installation location To implement Audi pre sense turn-off assist, the vehicle requires: > Adaptive cruise assist with the ADR sensor, right G259 and the ACC control unit J428. > Front camera for driver assistance systems R242. > The control unit for laser distance control J1122.
Front camera for driver assistance systems R242
Adaptive cruise assist with ADR sensor, right G259 and ACC control unit J428
Control unit for laser distance control J1122 662_166
Function Turn-off assist is explained using a left turn-off situation in righthand traffic. In driving situations involving left-hand traffic, the function helps to driver to turn off to the right. The radar sensor of adaptive cruise assist, the front camera for driver assistance systems and the laser scanner of the laser distance control function continuously monitor the traffic in front of one's own vehicle. The front camera for driver assistance systems
and the laser scanner of the laser distance control function send the data they have acquired to the ACC control unit J428. The ACC control unit merges the data and can instruct other systems to initiate actions appropriate to the situation. The merging of data from various sources provides a very exact map of the vehicle periphery.
Switching turn-off assist off and on When Audi pre sense is off, turn-off assist is also off. In addition, turn-off assist can be switched off separately in the MMI menu. If
function is reactivated in the MMI. Turning the ignition off and on does not activate turn-off assist if it has been switched off sepa-
turn-off assist is switched off separately, it stays off until the
rately.
1)
Not available in all countries. Reference For further information about turning Audi pre sense on and off, refer to "Audi pre sense settings", page 76 ff.
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Turning off to the left The driver wants to turn off to the left with his vehicle (1). Turn-off assist can only assist the driver with turning off to the left if the vehicle (1) is travelling at a speed of less than 10 kph. As described under "Function", the radar sensor, the front camera and the laser scanner continuously monitor the traffic in front of one's own vehicle (1). When the turn signal is switched to the left position, the oncoming traffic is also monitored. When the turn signal is switched to the left position, the ACC control unit knows that the driver intends to turn off to the left. If the ACC control unit J1122 detects that turning off now would result in a critical situation involving oncoming traffic (2), it instructs the ABS control
unit J104 to reconfigure hydaulic brake assist. If the driver (1) were now to continue with the turn-off manoeuvre and start to drive away, this will be detected by the ACC control unit through the wheel speed sensors of the ABS control unit J104. In this case, the ACC control unit instructs the ABS control unit J104 to initiate an automatic emergency braking manoeuvre. The vehicle (1) comes to a standstill in its own lane due to the emergency braking manoeuvre. Visual and audible messages indicating that Audi pre sense is active appear in the instrument cluster.
Process diagram showing the working principle of Audi pre sense turn-off assist
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Key:
Reconfiguration of hydraulic brake assist
Automatic braking up to emergency braking intensity
Visual advance warning and/or indication of corrective action
Audible warning beep
System characteristics of the turn-off assist function > Turn-off assist is only available while turning off to the le ft or travelling at speeds below 10 kph. > The turn signals must be activated before turning off. > In right-hand-drive vehicles the system is only active when turning off to the left.
> In left-hand-drive vehicles the system is only active when turning off to the right. > If turn-off assist is active, this is indicated both visually and audibly.
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Pre sense evasion assist Audi pre sense evasion assist can aid the driver with an e vasion manoeuvre while approaching another vehicle. In models equipped with Audi pre sense evasion assist, the following actions can be taken: > Steering torque (corrective steering inputs). > Braking of individual wheels. > Display of corrective action by Audi pre sense in the instrument cluster (visual and audible).
Installation location To implement Audi pre sense evasion assist, the vehicle requires: > Adaptive cruise assist with the ADR sensor, right G259 and the ACC control unit J428. > Front camera for driver assistance systems R242. > The control unit for laser distance control J1122.
Front camera for driver assistance systems R242
Adaptive cruise assist with ADR sensor, right G259 and ACC control unit J428
Control unit for laser distance control J1122 662_166
Function Evasion assist is explained using an example in which one's own vehicle wants to pass by a vehicle on the left. Evasion assist behaves analogously when passing by a vehicle on the right. The radar sensor of adaptive cruise assist, the front camera for driver assistance systems and the laser scanner of the laser distance control function continuously monitor the traffic in front of one's own vehicle. The front camera for driver assistance systems
and the laser scanner of the laser distance control function send the data they have acquired to the ACC control unit J428. The ACC control unit merges the data and can instruct other systems to initiate actions appropriate to the situation. The merging of data from various sources provides a very exact map of the vehicle periphery.
Switching evasion assist off and on When Audi pre sense is off, evasion assist is also off. In addition, evasion assist can be switched off se parately in the MMI menu. If
function is reactivated in the MMI. Turning the ignition off and on does not activate evasion assist if it has been switched off sepa-
evasion assist is switched off separately, it stays off until the
rately.
Reference For further information about turning Audi pre sense on and off, refer to "Audi pre sense settings", page 76 ff. 96
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Evasion maneouvre The vehicle (1) wants to evade the vehicle (2) travelling ahead. As described under "Function", the radar sensor, the front camera and the laser scanner continuously monitor the traffic in front of one's own vehicle (1). Before evasion assist can provide the driver with assistance, Audi pre sense front has already identified a critical situation and initiated the following actions: > Visual prewarning. > Audible prewarning. > Prefilling of the brake system. > Adaptation of hydraulic brake assist. > Acute warning by braking impulse.
Evasion assist computes a suitable evasion l ine based on various items of information, such as one's own speed and the lane in which the vehicle ahead in driving. If vehicle (1) deviates too far from the evasion line within certain bounds, evasion assist will, after the acute warning is issued, try to guide the vehicle (1) along the evasion line by providing steering assistance along the evasion line of the vehicle (2). The vehicle (1) is additionally stabilised by braking individual wheels. Evasion assist can only help the driver (1) when the driver (1) carries out the evasion process actively by making corrective steering inputs himself. Visual and audible messages indicating that Audi pre sense is active appear in the instrument cluster. If the last possible evasion point has been surpassed, no assistance is provided by evasion assist.
Process diagram showing the working principle of Audi pre sense evasion assist
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Key:
Assistive steering torque
Braking of individual wheels
Visual advance warning and/or indication of corrective action
Audible warning beep
System characteristics of the evasion assist function > Evasion assist is active after the acute warning (brake warning) is issued. > Evasion assist is not active if the last possible evasion point has been surpassed. > Evasion assist does not provide assistance unless the driver is actively steering the vehicle.
> Evasion assist is available at speeds of between about 30 to 150 kph. > and helps the driver to steer around an obstacle on the left or right.
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Driver assistance systems Adaptive cruise assist Introduction Adaptive cruise assist is a new driver assist system which is offered for the first time in the Audi A8 (type 4N) as optional equipment. It combines 3 formerly independent systems - adaptive cruise control, Audi active lane assist with "early" corrective steering point and traffic jam assist - in a single driver assist system.
System configuration in the Audi Q7 (type 4M) and Audi A4/A5 (type 8W)
Adaptive cruise control(ACC)
Audi active lane assist "early" corrective steering point
Traffic jam assist
Adaptive cruise assist
System configuration in the Audi A8 (type 4N)
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With adaptive cruise assist, a combined longitudinal and lateral control assistance function is available for the first time at speeds ranging from 0 to 250 kph. "Longitudinal control" involves accelerating and braking the vehicle, while "lateral control" involves steering the vehicle. However, the driver must keep his hands on the steering wheel. With adaptive cruise assist, both longitudinal and late ral control functions are available to the driver. However, the driver can also deactivate the lateral control function so that only the longitudinal control function stays active. The vehicle behaves in much the same way as previously when driving with ACC. The longitudinal control function in the Audi A8 (type 4N) is largely identical to the 4th generation ACC system used in the Audi Q7 (type 4M) and in the Audi A4/A5 (type 8W). With adaptive cruise assist, it is not possible to deactivate the longitudinal control function while the lateral control function is active.
With the introduction of adaptive cruise assist, active lateral control of the vehicle is available at all speeds up to 250 kph. In the Audi Q7 (type 4M) or the Audi A4/A5 (type 8W), lateral control is the task of Audi active lane assist at 65 kph or higher. At speeds of less than 60 kph, it is the task of traffic jam assist if a traffic jam situation has been detected by the system. Lateral control may be interrupted for several seconds at the transition from active lateral control by Audi active lane assist to active lateral control by traffic jam assist, and vice versa. This interruption does not apply to adaptive cruise assist, where lateral control is provided continuously. As adaptive cruise assist is a driver assistance system, the driver is still fully responsible for operating the vehicle. The driver's hands must stay on the stee ring wheel. The system assists the driver, but does not relieve the driver of responsibility. Adaptive Drive Assist reduces the driver's workload and makes for more comfortable driving.
Reference For further information about adaptive cruise assist, refer to Self Study Programme 668 "Audi A8 (type 4N) Driver assistance systems." 98
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Intersection assist Functional description
Complex traffic situation at an intersection
Intersection assist is a new driver assist system, which is offered for the first time in the Audi A8 (type 4N). It helps the driver to avoid collisions with cross traffic ahead of the vehicle.
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Passing an narrow driveway exit with impaired visibility
Intersection assist helps the driver in situations in which cross traffic ahead of the vehicle can only be seen late due to impaired visibility. Impaired visibility situations such as this can occur at street intersections or when passing narrow entrances and exits.
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Complex situation when passing a main road In heavy traffic
Intersection assist also aids the driver in complex traffic situations in which, for instance, a road user crossing ahead of the vehicle is overlooked because the driver is concentrating on other traffic.
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Intersection assist only responds to cross traffic if the vehicle is travelling at a speed of at least 10 kph. Cross traffic can be a normal vehicle, a bus or a truck, but also a cyclist or motorcyclist.
If the cyclist or motorcyclist is recognised by the system, the system responds in exactly the same way as to a vehicle.
Intersection assist sensors
To implement intersection assist, the vehicle requires two additional radar sensors, which are located behind the front bumper. These radar sensors are identical in design to the rear radar sensors of the Audi A8 and are installed for the first time at this position in the Audi. Both radar sensors monitor the area to the front left and right of the vehicle. Due to the positioning of the two
radar sensors at the extreme front left and front right of the vehicle, the system can, in certain situations, detect cross traffic even before the driver sees it. Intersection assist utilises this lead time to provide the driver with feedback on critical cross traffic as early as possible so that the driver can respond to this situation.
Reference For further information about intersection assist, refer to Self Study Programme 668 "Audi A8 (type 4N) Driver assistance systems." 99
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Driver assistance systems control unit J1121 Introduction The driver assistance systems control unit J1121 is a new control unit, which is used for the first time in the Audi A8 (type 4N). The control unit will be available in a total of 4 different versions at the launch of the Audi A8. The versions have the following designations: > Version A0 (basic version) > Version A > Version B > Version C (version with widest range of functions)
in the vehicle, version A0 is sufficient. If, for example, the optional surround view cameras are ordered, this requires the installation of version C. The optional surround view cameras are currently the only option which necessitates the installation of version C. Version C will in future also be required by other park assistance systems in the Audi A8 (type 4N), but these systems will not be introduced until a later date.
Which versions are required in a specific Audi A8 (type 4N) depends on which driver assistance systems are ordered. If only the standard driver assistance systems are installed
Th individual versions are based on each other. The higher the version number, the more hardware and software are integrated in the control unit. However, an external analysis of the control unit shows that it is only possible to differentiate visually between 2 different versions.
Control unit of versions A0 and A
Control unit of versions B and C
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The driver assistance systems control unit J1121 is the master control unit for the following driver assistance systems: > > > > >
Basic version of main beam assist Matrix LED main beam assist Intersection assist Surround view cameras Parking system plus (in version C only, otherwise electrical system control unit J519)
> Active lane departure warning > Emergency assist > Camera-based traffic sign recognition
Reference For further information about the driver assistance systems control unit J1121, refer to Self Study Programme 668 "Audi A8 (type 4N) Driver assistance systems." 100
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Control unit for laser distance control J1122 Installation location A laser scanner is used in the Audi A8 (type 4N) to implement complex driver assistance functions. It is installed in the centre of the bumper under the number plate carrier.
Function The general functional principle is similar to that of a radar sensor: instead of radar waves, the laser scanner emits laser beams which are reflected when they impinge on the surfaces of other objects. It is possible to measure the distance to an object by determining the elapsed time from emittance to reception of the reflected radiation components. The type of object is also determined. The reflection received by the scanner is made up of a multiplicity of dots known as dot clouds. The contours of the object are more well-defined than those acquired with radar technology, making it easier to classify objects.
Laser unit with control unit for laser distance control J1122 662_188
The horizontal detection zone covers an angular range of about 145°. The range is approx. 80 m on average, and object recognition is possible from a distance of 10 cm. The laser scanner is, therefore, the ideal complement to the long-range radar. Although the radar system has a much longer range (250 m), the coverage angle of approx. 35° is much less than that of the laser scanner.
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Object contours are recognisable in detail
Calibration The installation position of the laser scanner can be adjusted by service personnel as it is subject to tolerances. Provision has been made for vertical adjustment only. The adjustment is similar to that of the ACC and is carried out using a new optical target (calibration board). 662_190
Laser scanner calibration board VAS 6430/12
ACC unit To accommodate the laser scanner, an ACC unit is used on the right-hand side of the Audi A8 (type 4N). The laser scanner assumes the function of the second ACC unit. ACC is no longer available as a separate option in the Audi A8 (type 4N), but rather is an optional feature of "Adaptive Cruise Assist" (ACA) in the Tour assistance package. The 4th generation ACC system is identical in design and basic functions to the ACC of the Audi Q7 (type 4M).
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4th generation ACC unit
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Infotainment and Audi connect Overview of versions The Audi A8 (type 4N) comes equipped with the latest-generation modular infotainment system (version MIB2+). The customer can choose between 2 MMI versions: MMI Radio plus and MMI Navigation plus. Both versions are based technically on MIB2+ High.
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1)
7UH for countries without navigation map data
2)
EL0 for markets without Audi connect IT0 means without Audi connect licence without Audi connect SIM IT1 means with Audi connect licence without Audi connect SIM IT2 means without Audi connect licence with Audi connect SIM IT3 means with Audi connect licence with Audi connect SIM 4) If a single-DVD player (7D5) and a DVD changer (6G0) are ordered together, the PR. No. is 6G2 5) The Audi connect data module becomes a fully fledged telephone module in combination with SAP 6) For markets in which no coupling box (external aerial connection for smartphone) is available 7) If a digital radio (QV3) and a TV tuner (QV1) are ordered together, the PR no. is QU1 If a digital radio (QV3) and a TV tuner with CI card reader (Q0A) are ordered together, the PR no. is Q0B 8) Auto SOS only (IW1) or Auto SOS and Service (IW3) depending on country 9) IW3 is mandatory 10) The Comfort key (4F2/4I3) is mandatory 3)
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MMINavigationplus(I8T+7UG)
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10.1" touchscreen with 1540 x 720 pixel resolution
10.1" touchscreen with 1540 x 720 pixel resolution
8.6" touchscreen with 1280 x 660 pixel resolution
8.6" touchscreen with 1280 x 660 pixel resolution
Audivirtualcockpit(9S8)
Audivirtualcockpit(9S8) 3D SSD navigation system (7UG)1))
AM/FM radio
AM/FM radio Audi connected Radio (Internet radio) Satellite radio for North America (Sirius) (QV3)
Audi music interface with 2 USB ports and 1 SDXC card reader (UF7) Audisoundsystem(9VD)
Audi music interface with 2 USB ports, 1 SDXC card reader and (depending on market) 1 SIM card reader (UF7) Audisoundsystem(9VD)
Bluetoothinterface(9ZX)
Bluetoothinterface(9ZX) UMTS/LTE data module (EL3)² including Audi connect (IT3)3)
Optional equipment Single DVD drive (7D5)4)
Single DVD drive (7D5)4)
DVD changer (6G0)4)
DVD changer (6G0)4)
Audi music interface in the rear with 2 USB ports (UF8)
Audi music interface in the rear with 2 USB ports (UF8) Audi smartphone interface (IU1)
RearSeatRemote(QW5)
RearSeatRemote(QW5) 5)
Audi phone box (including wireless charging) (9ZE)
Audi phone box (including wireless charging) (9ZE)
Audi phone box light (for wireless charging only) (9ZV)5), 6)
Audi phone box light (for wireless charging only) (9ZV)5), 6)
Audi phone box light rear only for 4 seater models (for wireless charging only) (QF6) (for China only)
Audi phone box light rear only for 4 seater models (for wireless charging only) (QF6) (for China only)
Phone connectivity in the rear cabin including Audi phone box rear (QF7 for 4-seater models/QF8 for 5-seater models without wireless charging)
Phone connectivity in the rear cabin including Audi phone box rear (QF7 for 4-seater models/QF8 for 5-seater models without wireless charging)
Bang & Olufsen Premium Sound System with 3D sound (9VS)
Bang & Olufsen Premium Sound System with 3D sound (9VS)
Bang & Olufsen Advanced Sound System with 3D sound (8RF)
Bang & Olufsen Advanced Sound System with 3D sound (8RF)
)
) DAB digital radio (QV3)⁵
DAB digital radio (QV3)⁵
TV tuner (QV1/Q0A)7) 8)
Auto SOS & connect vehicle-specific services (IW3)
Auto SOS & connect vehicle-specific services (IW3)8) Audi connect key (2F1)9), 10) Integrated Rear Seat Entertainment including 2 Audi tablets (9WF) Audi connect anti-theft vehicle locating system (7I1 / with driver card 7I2)
Reference For further information about the infotainment systems and Audi connect, refer to Self Study Programme 666 "Audi A8 (type 4N) Infotainment". 103
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Inspection and maintenance Overview The following service intervals are displayed:
> Oil change service > Mileage-based service events > Time-based service events
Example of a service interval display in the Audi virtual cockpit
Car
·
Service intervals
Next oil change in Flexible service event
---- km
/ 730 days
Next inspection in 30,000 km / 730 days
Mileage-based service event
Time-based service event
Reset oil change interval 662_097
In new vehicles, the next oil change due field (flexible servicing event) is initially blank. This interval has to be computed from the driving profile and engine load and is not displayed until about 500 km have been
The value displayed in the mileage-based servicing events field is now 30,000 km for new vehicles and is decremented in increments of 100 km. The value in the field for the time-based servicing events is now 730 days (2 years) for new vehicles and is updated on a daily basis (upwards of a total mileage of about 500 km).
covered.
3.0lTFSIengine
3.0lTDIengine
Engine oil change
According to service interval display, between 15,000 km / 1 year and 30,000 km / 2 years depending on driving style and conditions of use.
Inspection
30,000km/2years
30,000km/2years
Pollen flter change interval
60,000km/2years
60,000km/2years
Air flter change interval
90,000 km
Brake uid change interval
Change after 3, 5, ... years
Spark plug change interval
60,000 km
Fuel flter change interval
–
60,000 km
Timing assembly
Chain (maintenance free)
Chain (maintenance free)
Gear oil change
No maintenance interval applies
No maintenance interval applies
Read out ash mass in the diesel particulate flter (in km)
–
at210,000km/thenevery30,000km
Oil standard
VW50800/VW50900
VW50400/VW50700
Air improvement system Flacons in the cabin fragrance system function unit GX43
30,000km/2years
30,000km/2years
Note The values given in the current service literature generally apply.
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60,000 km Change after 3, 5, ... years –
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Overview of service intervals for vehicles in the USA The Audi A8 (type 4N) is subject to fixed inspection and maintenance intervals in the USA.
USA e c i v r e s e g n a h c li O
10,000 miles / 1 year
e g n a h c li o h it w n io t c e p s n I
e g n a h c li o h it w n io t c e p s n I
e ic v r e s e g n a h c il O
20,000 miles / 2 years
30,000 miles / 3 years
40,000 miles / 4 years
e ic v r e s e g n a h c il O
50,000 miles / 5 years 662_098
Overview of maintenance intervals for vehicles in Canada The Audi A8 (type 4N) is subject to fixed inspection and maintenance intervals in Canada.
Canada e c i v r e s e g n a h c li O
15,000 km / 1 year
e g n a h c li o h it w n o i t c e p s n I
e g n a h c li o h it w n o i t c e p s n I
e ic v r e s e g n a h c li O
30,000 km / 2 years
45,000 km / 3 years
60,000 km / 4 years
e ic v r e s e g n a h c li O
75,000 km / 5 years 662_098
Overview of maintenance intervals for cars in China The Audi A8 (type 4N) is subject to fixed inspection and maintenance intervals in China.
China e g n a h c li o h it w n io t c e p s n I
10,000 km / 1 year later
e g n a h c li o h it w n io t c e p s n I
20,000 km / 1 year later
e g n a h c li o h it w n io t c e p s n I
30,000 km / 1 year later
e g n a h c li o h it w n io t c e p s n I
40,000 km / 1 year later 662_098
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Special tools and workshop equipment T40385 Removal tool
Usage: For removing the door mirror.
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Door mirror removal tool
AC service unit VAS 581 009
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Appendix Self study programmes For more information about the technology of the Audi A8 (type 4N), please refer to the following self study programmes.
SSP 410 Audi occupant protection – Passive systems
SSP 655 – Audi 3.0l V6 TFSI engine EA839 series
SSP 656 3.0l TDI engine series EA897evo2
SSP 663 Audi A8 (type 4N) Suspension
SSP 664 Audi A8 (type 4N) Electrics and electronics
SSP 665 Audi A8 (type 4N) New air conditioning features and introduction of refrigerant R744
SSP 666 Audi A8 (type 4N) Infotainment and Audi connect
SSP 668 Audi A8 (type 4N) Driver assistance systems
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All rights reserved. Subject to revision. Copyright AUDI AG
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[email protected] AUDI AG
D-85045 Ingolstadt Technical status 08/17
