Analyze and Evaluate Electrical and Electronic Elect ronic Faults Faults in i n Engine Management Management Systems AURT575093A
Name: Hyun Hak Han Group: 108 Teacher: Brendon Couch
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Vehicle Details
Vehicle make and model Ford (Falco (Falcon n AU3 FORTE SR) Year of manufacture 2002 Engine configuration and size 4.0L (3995cc), Inline 6 cylinder Engine Performance specifications Horse power: 178 hp (102 kW) at 5200 rpm Torque: 240 KW, 5200rpm
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Engine Management System overview Function
The car running best performance and good fuel consumption.
Basic operation
It collects information from various sensors such as throttle position sensor, air flow sensor, air temperature, air mass, engine temp. , oxygen sensor, sensor, engine speed etc, then process all the information to actuate the engine part efficiently
Performance
good fuel consumption, good engine performance , and very clean emission
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Engine Management Sub Systems Air system
Function To control the air flow into the cylinder and deliver the sufficient and filtered air to the engine and signal to the ECU air flow, temp. , throttle position.
Basic operation Filter the air by the air filter and measure the air flow and temp. Also throttle position then send signals to the PCM
Performance No impurities in the air, air, signal correct sensor s ensor readings
Diagnostic equipment Scan tool, test light
Test procedures Firstly visual inspection, resistance and voltage test by a multi meter at sensors – instruction is indicated Sub system s ystem components section
Fuel injection system
Function
Deliver to the correct amount of fuel which is determined by PCM to the combustion chambers
Basic Operation
Pump the fuel from the fuel tank and deliver it to the each injector then inject the fuel with the correct amount and the correct timing
Performance Delivering to the correct amount of fuel which is calculated by PCM
Diagnostic equipment Multi meter, test light, Scan Tool
Test procedures Visual and smelling check for any leaks, sensor check
Ignition system
Function To provide the sufficient s ufficient voltage of spark at the correct timing
Basic Operation Transform the low voltage to the required high voltage and provide the sparks in the combustion chambers by the spark plugs
Performance Sufficient voltage of sparks, sparks at the right timing
Diagnostic equipment Multi meter, test light, test spark plug
Test procedures Voltage test by using the test spark plug
Electronic Control System
Function To calculate the ideal amount of fuel and control the whole engine management system
Basic Operation It receives all the information from various sensors, by analyzing the data it could determine the ideal amount of fuel and the correct spark timing then actuate the injector to s pray the specific amount of fuel and ignition system for sparks
Performance Very good fuel consumption, engine performance, low emission
Diagnostic equipment Scan tool, Multi meter, test light
Test procedures Use the scan tool Perform the self diagnostic procedure
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Sub System components and Electrical details Air system components
Throttle Position Sensor
Function – To signal to the ECU how far the throttle valve is open
Basic Operation – It generates the different voltage depending on the throttle valve position
Performance – Signal to ECU
Diagnostic Equipment – Multi meter
Test Procedure – Touch the negative lead of the multi meter to the ground wire and the positive lead to the signal wire then start the engine. The reading should be between 1V-5V 1V-5V while you move the throttle valve.
Component’s name
Wiring color
ECU Pin number
Performance
Throttle position sensor
BW
No.91
GROUND
Throttle position sensor
GB
No.89
SIGNAL
Throttle position sensor
OB
No.90
5V
purpose
Oxygen Sensor
Function – To measure the amount of oxygen in the exhaust
Basic Operation – when oxygen touches the sensor which is the ceramic zirconium with a thin layer of platinum coating one side side it makes makes electric charges causing the voltage reading.
Performance – voltage signal to ECU
Diagnostic Equipment - Multimeter
Test Procedure – remove the oxygen sensor from the vehicle, place it on a vice then connect each terminal to the corresponding lead on the multimeter. multimeter. Heat the sensor with a flame torch the voltage reading should fluctuate between 0.1-0.9V
Component’s name
Wiring color
ECU Pin number
Performance
Oxygen sensor
SY
No.71
IGN / B+
Oxygen sensor
SW
No.4
GROUND
Oxygen sensor
BW
No.91
GROUND
Oxygen sensor
GL
No.35
SIGNAL
purpose
Fuel system components
Fuel Injector
Function – to spray proper amount of fuel at the right timing
Basic Operation – it receives signal from ECU and open the solenoid for fuel to spray into the intake manifold
Performance – Correct amount of fuel and fine spray
Diagnostic Equipment - multimeter
Test Procedure – unplug the injector wire and measure the resistance of the two injector terminals by a multimeter
Component’s name
Wiring color
ECU Pin number
Performance
Injector #6
R
No.71
IGN / B+
Injector #6
XO
No.99
GROUND
Injector #5
R
No.71
IGN / B+
Injector #5
AB
Injector #4
R
No.71
IGN / B+
Injector #4
NZ
No.100
GROUND
Injector #3
R
No.71
IGN / B+
No.73
GROUND
purpose
Injector #3
NY
No.74
GROUND
Injector #2
R
No.71
IGN / B+
Injector #2
W
No.101
GROUND
Injector #1
R
No.71 / No.97
IGN / B+ , IGN / B+
Injector #1
A
No.75
GROUND
Pressure regulator
Function – To keep the constant pressure in a fuel rail
Basic Operation – it keeps the fuel pressure by a diaphragm and a spring in the regulator and increase the pressure when acceleration and also returns any excessive fuel to the tank
Performance – sufficient fuel pressure , increased fuel pressure when the throttle opens far
Diagnostic Equipment -
Test Procedure –
Fuel Pump
Function – To deliver fuel from the tank to the fuel injection system
Basic Operation – it pumps fuel by a diaphragm and oneway valve then build pressure and deliver fuel to fuel injection system.
Performance – constant fuel pressure
Component’s name
Diagnostic Equipment – test light Test Procedure – have an assistant turn the ignition on, pump should operate for 2 sec making sound. If not check the EFI fuse and short in the circuit between the fuel pump relay and the fuel pump
Wiring color
ECU Pin number
Performance
FUEL PUMP
B
No.
GROUND
FUEL PUMP
BY
RELAY NO.87
SWITCH
purpose
Ignition system components
Ignition coil
Function – to transform the low voltage to high voltage
Basic Operation – it is a step-up voltage transformer which can be achieved by the different numbers of winding in the two coils.
Performance – high enough voltage
Diagnostic Equipment - Multimeter
Test Procedure – Use the multimeter, measure the resistance between the positive and negative terminals then compare the reading with the primary coil resistance specification. And measure the resistance between the positive and high-tension terminal then compare it with the secondary coil resistance specification.
Component’s name
Wiring color
ECU Pin number
Performance
Ignition coil#1<1.6>
RG
34
12V
Ignition coil#1<1.6>
YB
27
GROUND
Ignition coil#2<5.2>
RG
34
12V
Ignition coil#2<5.2>
YR
21
GROUND
Ignition coil#3<4.3>
RG
34
12V
Ignition coil#3<4.3>
YW
19
GROUND
purpose
Distributor
Component’s name
Function – to direct the high voltage to the spark plugs in order at the right timing
Basic Operation – it turns as the crankshaft turns then direct the high voltage to the right spark plug to fire in order
Performance – right firing order , correct timing
Diagnostic Equipment – multimeter and feeler gauge
Test Procedure – measure the air gap with a feeler f eeler gauge and measure the resistance between the specific terminals as listed in the specification below Wiring color
ECU Pin number
Performance
purpose
ECU components
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ECU (computer)
Function – to control the whole engine management system efficiently
Basic Operation – Collects all the information from the sensors then determines the proper amount of fuel to inject and activate the necessary parts
Performance – good engine performance , high fuel efficiency and low emission
Diagnostic Equipment – scanning tool
Test Procedure – connect a scanning tool to the OBD connector then follow the self diagnosis procedure
Engine Management System Faults Engine Check Light On, Codes indicate: Check engine coolant temperature. Check throttle position sensor Check Ignition system a)
Fault Symptoms Abnormally higher idle speed all the time, poor fuel economy, economy, hesitation under acceleration, poor engine performance
b) Causes of the fault
Faulty coolant temperature sensor, faulty thermostat, faulty throttle position sensor, sensor, faulty ignition coil or any broken wiring
c) Diagnostic Equipment and Procedures
Multimeter is used to test the sensors Checking a TPS and an ignition coil is indicated above in the sub system components part section.
Checking a thermostat can be done by putting the thermostat in hot water and seeing if it is open op en
Poor Fuel Economy a) Fault Symptoms
Excessive fuel consumption b) Causes of the fault
Dirty or clogged air filter, filter, incorrectly set ignition timing, faulty fuel injector, low tire pressure c) Diagnostic Equipment and Procedures
Visual inspection at air filter Use the timing check light to check the ignition timing, it should line up with 10-degree on the scale Check the tire pressure with a tire pressure pres sure gauge Check the injectors as indicated above in the sub system components part section.
Engine detonation / spark knock a) Fault Symptoms
Knocking noise, vibration, lack of power b) Causes of the fault
Incorrect spark timing c) Diagnostic Equipment and Procedures
Use the timing check light to check the ignition timing, it should line up with 10-degree on the scale
Hesitation under acceleration a. Fault Symptoms
Slow acceleration pedal response, poor acceleration b. Causes of the fault
Fuel filter clogged, faulty injectors, blocked exhaust system, faulty TPS c. Diagnostic Equipment and Procedures
Replace the fuel filter Check the injectors as indicated above in the sub system components part section. Test drive with the unbolted exhaust manifold
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References
http://en.wikipedia.org/wiki/Engine_management_system Relic Wiring Diagrams – Volume Volume 1 (Greg Williams, Chris Anderson and Les Gram) Electronic fuel injection diagnosis and testing manual no2. (Published by David Boyce) EFI and Powertrain Powertrain management management systems. (Published (Published by greg willams, chris Anderson and les garam.)
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COLOR CODE
A - tan
N - brown
V – violet
B - black
O - orange
W – white
G - green
P - purple
Y – yellow
K - pink
R - red
X – light green
L - blue
S - gray
Z – light blue
