Automatic A245E,A246E

CH-6

CHASSIS – AUTOMATIC TRANSAXLE

A246E AUTOMATIC TRANSAXLE 1. General The compact, lightweight, and high-capacity 4-speed A246E automatic transaxle [ECT (Electronically Controlled Transaxle)] is used. The basic construction and operation are the same as A245E automatic transaxle on the ’02 Corolla. However, the gear ratio and fluid type have been changed.

Specification Model

’03 Corolla Matrix

’02 Corolla

Transaxle Type

A246E

A245E

1st

4.005

3.643

2nd

2.208

2.008

3rd

1.425

1.296

4th

0.981

0.892

Reverse

3.272

2.977

2.962

2.655

7.3 (7.7, 6.4) *2

7.6 (8.0, 6.7) *2

ATF Type T-IV

ATF D-II or equivalent

73.0 (160.9)

73.3 (161.6)

Gear Ratio*1

Differential Gear Ratio Fluid Capacity Liters (US qts, Imp.qts) Fluid Type Dry Weight *1: Counter Gear Ratio Included *2: Differential Included

kg (lb.)

CH-7


Front Planetary Gear

Rear Planetary Gear

B2

B3 F2

B1

C2

Counter Drive Gear C1

F1

Input Shaft

Differential Drive Pinion Counter Driven Gear B4 Counter Shaft

C3 F3

221CH01

U/D Planetary Gear

Specification C1

Forward Clutch

C2

Direct Clutch

C3

U/D Direct Clutch

B1

2nd Coast Brake

B2

2nd Brake

B3

1st & Reverse Brake

B4

U/D Brake

3

F1

No.1 One-Way Clutch

18

F2

No.2 One-Way Clutch

F3

U/D One-Way Clutch

Front Planetary y Gear

Rear Planetary y Gear

U/D Planetary y Gear

4 3

The No. of Discs

3 Band Width

mm (in.)

25 (0.98) 3

The No. of Discs

The No. of Sprags p g

6

20 24

The No. of Sun Gear Teeth

39

The No. of Pinion Gear Teeth

16

The No. of Ring Gear Teeth

71


27


18


62


33


20


73

CH-8


2. Torque Converter This torque converter has optimally designed fluid passages and impeller configuration resulting in substantially enhanced transmission efficiency to ensure better starting, acceleration and fuel economy. Furthermore, a hydraulically operated lock-up mechanism which cuts power transmission losses due to slippage at medium and high speeds is used.

Specification

Torque Converter Type

3-Element, 1-Step, 2-Phase (with Lock-up Mechanism)

Stall Torque Ratio

1.95

Turbine Runner Pump Impeller

Lock-up Clutch Stator

One-way Clutch

218CH02

3. Oil Pump The oil pump is driven by the torque converter. It lubricates the planetary gear units and supplies operating pressure for the hydraulic control system.

Specification Gear

Gear Teeth

Drive Gear

9

Driven Gear

11

Pump Body

Driven Gear

Stator Shaft

Drive Gear 2180H03

CH-9


4. Planetary Gear Unit Construction The gear train consists of three multi-plate clutches, three multi-plate brakes, a single band type brake, three one-way clutches, and three planetary gear units each containing a sun gear, pinion gears and a ring gear. Counter Drive Gear

Rear Planetary Gear

Front Planetary Gear C1

UD Planetary Gear

Intermediate Shaft

C2 F1

Input Shaft

B1 B3 B2

B2

C3

F3

Counter Driven Gear

F2

Ring Gear

Differential Drive Pinion

218CH04

Function of Component Component

Function

C1

Forward Clutch

Connects input shaft and front ring gear.

C2

Direct Clutch

Connects input shaft and front & rear planetary sun gear.

C3

U/D Direct Clutch

Connects U/D sun gear and U/D planetary carrier.

B1

2nd Coast Brake

Prevents front & rear planetary sun gears from turning either clockwise or counterclockwise.

B2

2nd Brake

Prevents front & rear planetary sun gears from turning counterclockwise when F1 operates.

B3

1st & Reverse Brake

Prevents rear planetary carrier from turning either clockwise or counterclockwise.

B4

U/D Brake

Prevents U/D sun gear from turning either clockwise or counterclockwise.

F1

No.1 One-Way Clutch

When B2 is operating, prevents counterclockwise rotation of front & rear planetary sun gear.

F2

No.2 One-Way Clutch

Prevents rear planetary carrier from turning counterclockwise

F3

U/D One-Way Clutch

Prevents U/D sun gear from turning clockwise.

Planetary Gears

These gears changes the route through which driving force is transmitted, in accordance with the operation of each clutch and brake, in order to increase or reduce the input and output speed.

CH-10


Transaxle Power Flow Shift Lever Position

Gear

P

Solenoid Valve C1

C2

S1

S2

Park

ON

OFF

R

Reverse

ON

OFF

N

Neutral

ON

OFF

1st

ON

OFF

2nd

ON

ON

3rd

OFF

ON

4th

OFF

OFF

1st

ON

OFF

2nd

ON

ON

3rd*

OFF

ON

1st

ON

OFF

2nd*

ON

ON

D

2

L

C3

B1

B2

B3

B4

F1

F2

F3

1st Gear (D or 2 Position)

C1

C2 F1 B1

B4

F3

F2

: Operating *: Down-shift only in the 3rd gear for the 2 range and 2nd gear for the L range no up-shift

B3

B2

C3

218CH05

CH-11

CHASSIS – AUTOMATIC TRANSAXLE 2nd Gear (D Position) C1

C2 F1

B1 B3 B4

F3

F2

B2

C3

218CH06

3rd Gear (D Position) C1

C2 F1

B1 B3 B4

F3

F2

B2

C3

218CH07

4th Gear (D Position) C1

C2 F1

B1 B3 B4

F3

F2

B2

C3

218CH08

CH-12


1st Gear (L Position) C1

C2 F1

B1 B3 B4

F3

F2

B2

C3

218CH09

2nd Gear (2 Position) C1

C2 F1

B1

B3 B4

F3

F2

B2

C3

218CH10

Reverse Gear (R Position) C1

C2 F1

B1 B3

B4

F3

F2

B2

C3

218CH11

CH-13


5. Valve Body Unit General The valve body consists of the upper and lower valve bodies and four solenoid valves. Solenoid Valve SLT

Upper Valve Body Solenoid Valve S1 Solenoid Valve S2

Lower Valve Body

Solenoid Valve SL 218CH12

Upper Valve Body Lock-up Relay Valve

3-4 Shift Valve

2nd Regulator Valve

3-way Check Valve

B-4 Orifice Control Valve

218CH13

CH-14


Lower Valve Body

Primary Regulator Valve

C-1 Orifice Control Valve

SLT Damper 2-3 Shift Valve

2nd Coast Modulator Valve Solenoid Modulator Valve Low Coast Modulator Valve

1-2 Shift Valve

Reverse Control Valve

Accumulator Control Valve 218CH14

Function of Solenoid Valve Solenoid Valve

Function

S1

Controls hydraulic pressure applied to 2-3 shift valve.

S2

Controls hydraulic pressure applied to 1-2 and 3-4 shift valve.

SL

Controls hydraulic pressure to the rear side of the lock-up clutch.

SLT

Controls line pressure.

CH-15


6. Electronic Control System General The electronic control system of the A246E automatic transaxle is listed below.

System

Function

’03 Corolla Matrix

’02 Corolla

A246E

A245E

Line Pressure Optimal Control

Actuates the solenoid valve SLT to control the line pressure in accordance with information from the ECM and the operating condition of the transaxle.

—

Shift Control in Uphill/Downhill Traveling

Restricts the 4th upshift or to provide appropriate engine braking by using the ECM to determine whether the vehicle is traveling uphill or downhill.

—

Shift Timing Control

The ECM sends current to the solenoid valve S1 and/or S2 based on signals from each sensor and shifts the gear.

Lock-up Timing Control

The ECM sends current to the solenoid valve SL based on signals from each sensor and engages or disengages the lock-up clutch.

Engine Torque Control

Temporarily retards the engine ignition timing to improve shift feeling during up or down shifting.

“N” to “D” Squat Control

When the shift lever is shifted from “N” to “D” range, the gear is temporarily shifted to 2nd and then to 1st to reduce vehicle squat.

CH-16


Construction The configuration of the electronic control system in the A246E automatic transaxle is as shown in the following chart. SENSORS CRANKSHAFT POSITION SENSOR

ENGINE COOLANT TEMP. SENSOR

THROTTLE POSITION SENSOR

ACTUATORS NE

S1

THW S2

R, 2, L ECM

SENSOR*1

SKID CONTROL ECU*1 COMBINATION METER

ODLP SPD

VEHICLE SPEED SENSOR*2 STOP LIGHT SWITCH

OVERDRIVE SWITCH

SOLENOID VALVE SLT

NSW SL

ABS SPEED

SOLENOID VALVE S2

VTA SLT

PARK/ NEUTRAL POSITION SWITCH

SOLENOID VALVE S1

W STP

ODMS

SIL

SOLENOID VALVE SL

O/ D OFF INDICATOR LIGHT

MALFUNCTION INDICATOR LAMP

DATA LINK CONECTOR 3

TC, WFSE 221CH02

*1: Models with ABS *2: Models without ABS


CH-17

Layout of Component O/D OFF Indicator Light

MIL

ECM

DLC3 Stop Light Switch Overdrive Switch

Park/Neutral Position Switch

Solenoid Valve S1 Solenoid Valve S2 Solenoid Valve SL

Solenoid Valve SLT 222CH01

CH-18


Line Pressure Optimal Control The line pressure is controlled by using a solenoid valve SLT. Through the use of the solenoid valve SLT, the line pressure is optimally controlled in accordance with the engine torque information, as well as with the internal operating conditions of the torque converter and the transaxle. Accordingly, the line pressure can be controlled minutely in accordance with the engine output, driving condition, thus realizing smooth shift characteristics and optimizing the workload on the oil pump. Primary Regulator Solenoid Valve SLT

Line Pressure

Solenoid Drive Signal Fluid Pressure

ECT

Shift Position Shift Range

Engine

Throttle Valve Opening Engine Speed

Current

Pump

Throttle Pressure

ECM

178CH09

CH-19

CHASSIS – AUTOMATIC TRANSAXLE Shifting Control in Uphill/Downhill Driving 1) General

With shifting control in uphill/downhill driving, the ECM calculates the throttle opening angle and the acceleration rate to determine whether the vehicle is in the uphill or downhill state. While driving uphill on a winding road with ups and downs, the 4th upshift is restricted to ensure a smooth drive. Also, if a brake application is detected while the ECM judges a downhill travel in 4th, the transmission automatically downshifts to 3rd in order to provide an appropriate engine brake.

Uphill Corner

3rd

4th

3rd

4th

Without Control 3rd

4th

3rd

4th

With Control Brake operation

Shifting up to 4th gear after down shifting to 3rd is prohibited when uphill driving is judged by the ECM.

The down-shift to 3rd gear occurs upon braking when downhill driving is judged by the ECM. 162CH09

2) Uphill/Downhill Judgment The actual acceleration calculated from the speed sensor signal is compared with the reference acceleration stored in the ECM to judge uphill or downhill driving. The ECM judges an uphill condition if the actual acceleration is smaller than the reference acceleration, and restricts the 3rd to 4th upshift after a 4th to 3rd downshift has occurred. Also, the ECM judges a downhill condition if the actual acceleration is greater than the reference acceleration, and restricts the 4th upshift while traveling in 3rd. If a brake application is detected while traveling in 4th, it downshifts to 3rd. Actual Acceleration < Reference Acceleration

Actual Acceleration > Reference Acceleration

Reference acceleration Actual acceleration Smaller Greater Uphill

Downhill 162CH10

CH-20


Diagnosis When the ECM detects a malfunction, It makes a diagnosis and memorizes the failed section. Furthermore, the MIL (Malfunction Indicator Lamp) in the combination meter illuminates or blinks to inform the driver. At the same time, the DTCs (Diagnosis Trouble Codes) are stored in memory. The DTCs can be read by connecting a hand-held tester. For details, see the 2003 Corolla Matrix Repair Manual (Pub. No. RM940U). Fail Safe This function minimizes the loss of operability when any abnormality occurs in each sensor or solenoid.

Fail Safe List Malfunction Part

Function

Vehicle Speed Signal

During a speed sensor malfunction, the vehicle speed is detected through signals from the crankshaft position sensor and shift position signal to maintain normal control.

Solenoid Valve SL

If the ECM detects a malfunction, it turns the SL solenoid valve OFF.

Solenoid Valve S1 or S2

During a malfunction of solenoid valve S1 or S2, the current to the faulty solenoid valve is cut off and control is achieved by operating the normal solenoid valve. Shift control is opened as described in the table below, depending on the failed solenoid.

Normal Position

D

2

L

Solenoid Valve

Solenoid Valve S1 Malfunctioning

Solenoid Valve S2 Malfunctioning

Solenoid Valve

Solenoid Valve

Both Solenoid Malfunctioning

Gear

Gear when shift slector is manually operated

x

1st

O/D

OFF

x

O/D

O/D

3rd

OFF

x

O/D

O/D

OFF

O/D

OFF

x

O/D

O/D

x

ON

3rd

ON

x

1st

O/D

2nd

x

ON

3rd

OFF

x

O/D

O/D

ON

3rd

x

ON

3rd

OFF

x

O/D

O/D

ON

OFF

1st

x

OFF

1st

ON

x

1st

1st

ON

ON

2nd

x

ON

2nd

ON

x

1st

1st

S1

S2

ON

OFF

ON

Gear

S1

S2

1st

x

ON

ON

2nd

x

OFF

ON

3rd

OFF

OFF

ON

Gear

S1

S2

3rd

ON

ON

3rd

x

ON

O/D

x

OFF

1st

ON

ON

OFF

x: Malfunctions

CH-21


7. Shift Control Mechanism General The overdrive switch is a momentary type. A shift lock system consists of the key interlock device and shift lock mechanism, has been adopted. An EA (Energy Absorbing) mechanism has been adopted in the shaft of the shift lever to dampen the impact that is directed to the driver during a collision. When an impact is applied to the shift lever, this mechanism causes the tip of the lever to break the plastic portion in order to dampen the impact.

Impact

Break Portion Before Collision

Plastic Portion Break After Collision 221CH29

Overdrive Switch The O/D (Overdrive) switch is the momentary type. The operation of this switch is described below: a) Turn the ignition switch from OFF to ON turns the overdrive ON. b) Pressing the O/D switch closes the contact points, and releasing the switch opens the contact points. c) Accordingly, pressing the switch causes the signal to be input into the ECM. d) The ECM turns OFF the overdrive (O/D OFF indicator light turn ON). e) Pressing the O/D switch again turns the overdrive back ON (O/D OFF indicator light turns OFF).

(d) ECM

ODLP ODMS (c)

O / D OFF Indicator Light

(d)

O/D OFF Indicator ON Light OFF

(b) O/D Switch

(e)

ON OFF

O/D Switch (Momentary Type)

Ignition Switch

ON OFF

(a)

(a) 172GN01

CH-22


Shift Lock System A shift lock system consists of the key interlock device and shift lock mechanism, that prevents the unintended operation of the shift lever has been provided. A mechanical key interlock device using a key lock cable has been adopted. An electrical shift lock mechanism, in which a shift lock solenoid and a shift lock ECU are integrated is used.

Shift Lock Override Button Shift Lock Unit Shift Lock Solenoid Shift Lock ECU Stop Light Switch Key Lock Cable 222CH02

Automatic A245E,A246E

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