Automatic A245E,A246E

CHASSIS AUTOMATIC TRANSAXLECH-6

A246E AUTOMATIC TRANSAXLE

1. General

The compact, lightweight, and high-capacity 4-speed A246E automatic transaxle [ECT (ElectronicallyControlled 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 CorollaTransaxle Type A246E A245E

1st 4.005 3.6432nd 2.208 2.008

Gear Ratio*1 3rd 1.425 1.2964th 0.981 0.892

Reverse 3.272 2.977Differential Gear Ratio 2.962 2.655Fluid Capacity

Liters (US qts, Imp.qts) 7.3 (7.7, 6.4) *2 7.6 (8.0, 6.7) *2

Fluid Type ATF Type T-IV ATF D-II or equivalentDry Weight kg (lb.) 73.0 (160.9) 73.3 (161.6)

*1: Counter Gear Ratio Included*2: Differential Included

CHASSIS AUTOMATIC TRANSAXLE CH-7

221CH01

Counter Drive Gear

Rear Planetary Gear Front Planetary Gear

Input Shaft

Differential Drive Pinion

U/D Planetary Gear

Counter Shaft

Counter Driven Gear

B3 F2

F1

B2

C1

B1 C2

C3F3

B4

Specification

C1 Forward Clutch 4C2 Direct Clutch The No. of Discs 3C3 U/D Direct Clutch 3B1 2nd Coast Brake Band Width mm (in.) 25 (0.98)B2 2nd Brake 3B3 1st & Reverse Brake The No. of Discs 6B4 U/D Brake 3F1 No.1 One-Way Clutch 18F2 No.2 One-Way Clutch The No. of Sprags 20F3 U/D One-Way Clutch

p g24

The No. of Sun Gear Teeth 39Front Planetary Gear The No. of Pinion Gear Teeth 16y

The No. of Ring Gear Teeth 71The No. of Sun Gear Teeth 27

Rear Planetary Gear The No. of Pinion Gear Teeth 18yThe No. of Ring Gear Teeth 62The No. of Sun Gear Teeth 33

U/D Planetary Gear The No. of Pinion Gear Teeth 20yThe No. of Ring Gear Teeth 73


218CH02

Lock-up Clutch

Turbine RunnerPump Impeller

Stator

One-way Clutch

2180H03

Pump Body

Drive Gear

Driven Gear

Stator Shaft

2. Torque Converter

This torque converter has optimally designed fluid passages and impeller configuration resulting insubstantially enhanced transmission efficiency to ensure better starting, acceleration and fuel economy.

Furthermore, a hydraulically operated lock-up mechanism which cuts power transmission losses due toslippage at medium and high speeds is used.

Specification

Torque ConverterType

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

Stall Torque Ratio 1.95

3. Oil Pump

The oil pump is driven by the torque converter. It lubricates the planetary gear units and supplies operatingpressure for the hydraulic control system.

Specification

Gear Gear TeethDrive Gear 9

Driven Gear 11


218CH04

Counter Drive Gear

UD Planetary Gear

Rear Planetary Gear

Front Planetary Gear

Intermediate Shaft

Input Shaft

Differential Drive PinionRing GearCounter

Driven Gear

B2 F3 C3

B3 F2

F1

B2B1

C2

C1

4. Planetary Gear Unit

Construction

The gear train consists of three multi-plate clutches, three multi-plate brakes, a single band type brake, threeone-way clutches, and three planetary gear units each containing a sun gear, pinion gears and a ring gear.

Function of Component

Component FunctionC1 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 BrakePrevents front & rear planetary sun gears from turning eitherclockwise or counterclockwise.

B2 2nd BrakePrevents front & rear planetary sun gears from turningcounterclockwise when F1 operates.

B3 1st & Reverse BrakePrevents rear planetary carrier from turning either clockwise orcounterclockwise.

B4 U/D BrakePrevents U/D sun gear from turning either clockwise orcounterclockwise.

F1 No.1 One-Way ClutchWhen B2 is operating, prevents counterclockwise rotation offront & rear planetary sun gear.

F2 No.2 One-Way Clutch Prevents rear planetary carrier from turning counterclockwiseF3 U/D One-Way Clutch Prevents U/D sun gear from turning clockwise.

Planetary GearsThese gears changes the route through which driving force istransmitted, in accordance with the operation of each clutch andbrake, in order to increase or reduce the input and output speed.


218CH05

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

Transaxle Power Flow

ShiftLever Gear

Solenoid ValveC C C B B B B F F FLever

PositionGear

S1 S2C1 C2 C3 B1 B2 B3 B4 F1 F2 F3

P Park ON OFF R Reverse ON OFF N Neutral ON OFF

1st ON OFF

D2nd ON ON

D3rd OFF ON 4th OFF OFF 1st ON OFF

2 2nd ON ON 3rd* OFF ON

L1st ON OFF

L2nd* ON ON

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

1st Gear (D or 2 Position)


218CH06

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

218CH07

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

218CH08

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

2nd Gear (D Position)

3rd Gear (D Position)

4th Gear (D Position)


218CH09

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

218CH10

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

218CH11

B4 F3 C3

B3 F2

F1

B2B1

C1

C2

1st Gear (L Position)

2nd Gear (2 Position)

Reverse Gear (R Position)


218CH12

Solenoid Valve SLT Upper Valve Body

Solenoid Valve S1

Solenoid Valve S2

Solenoid Valve SLLower Valve Body

218CH13

Lock-up Relay Valve 2nd Regulator Valve

3-way Check Valve

B-4 Orifice Control Valve

3-4 Shift Valve

5. Valve Body Unit

General

The valve body consists of the upper and lower valve bodies and four solenoid valves.

Upper Valve Body


218CH14

Primary Regulator Valve C-1 Orifice Control Valve

SLT Damper

2nd Coast Modulator Valve

Solenoid Modulator Valve

Low Coast Modulator Valve

Accumulator Control ValveReverse Control Valve

1-2 Shift Valve

2-3 Shift Valve

Lower Valve Body

Function of Solenoid Valve

Solenoid Valve FunctionS1 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.


6. Electronic Control System

General

The electronic control system of the A246E automatic transaxle is listed below.

System Function

03CorollaMatrix

02Corolla

A246E A245E

Line Pressure OptimalControl

Actuates the solenoid valve SLT to control theline pressure in accordance with informationfrom the ECM and the operating condition of thetransaxle.

Shift Control inUphill /DownhillTraveling

Restricts the 4th upshift or to provideappropriate engine braking by using the ECM todetermine whether the vehicle is traveling uphillor downhill.

Shift Timing ControlThe ECM sends current to the solenoid valve S1and/or S2 based on signals from each sensor andshifts the gear.

Lock-up Timing ControlThe ECM sends current to the solenoid valve SLbased on signals from each sensor and engagesor disengages the lock-up clutch.

Engine Torque Control Temporarily retards the engine ignition timing toimprove shift feeling during up or down shifting.

N to D Squat ControlWhen the shift lever is shifted from N to Drange, the gear is temporarily shifted to 2nd andthen to 1st to reduce vehicle squat.


221CH02

SENSORS ACTUATORS

CRANKSHAFT POSITION SENSOR

ENGINE COOLANT TEMP. SENSOR

THROTTLE POSITION SENSOR

PARK/NEUTRALPOSITION SWITCH

ABS SPEED SENSOR*1

SKID CONTROL ECU*1

COMBINATION METER

VEHICLE SPEED SENSOR*2

STOP LIGHT SWITCH

OVERDRIVE SWITCH

NE

THW

VTA

NSWR, 2, L

SPD

STP

ODMS

ECM

S1

S2

SLT

SL

ODLP

W

SILTC, WFSE

SOLENOID VALVE S1

SOLENOID VALVE S2

SOLENOID VALVE SLT

SOLENOID VALVE SL

O/D OFF INDICATOR LIGHT

MALFUNCTIONINDICATOR LAMP

DATA LINK CONECTOR 3

Construction

The configuration of the electronic control system in the A246E automatic transaxle is as shown in thefollowing chart.

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


222CH01

O/D OFF Indicator Light MIL

ECM

DLC3Stop Light Switch

Overdrive Switch

Park/Neutral Position Switch

Solenoid Valve S1

Solenoid Valve S2

Solenoid Valve SL

Solenoid Valve SLT

Layout of Component


178CH09

Primary Regulator

Line Pressure

Pump

Fluid Pressure

Current

Throttle Pressure

Solenoid Valve SLT

Solenoid Drive Signal

ECT Shift PositionShift Range

EngineThrottle Valve OpeningEngine Speed

ECM

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 withthe internal operating conditions of the torque converter and the transaxle. Accordingly, the line pressurecan be controlled minutely in accordance with the engine output, driving condition, thus realizing smoothshift characteristics and optimizing the workload on the oil pump.


162CH09

Uphill Corner

Without Control

With Control

3rd 4th 3rd 4th

4th3rd 3rd 4th

Brake operation

Shifting up to 4th gear after downshifting to 3rd is prohibited whenuphill driving is judged by the ECM.

The down-shift to 3rd gear occursupon braking when downhill drivingis judged by the ECM.

162CH10

Actual Acceleration < Reference Acceleration Actual Acceleration > Reference Acceleration

Reference accelerationActual acceleration

Smaller

Uphill

Greater

Downhill

Shifting Control in Uphill /Downhill Driving

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

2) Uphill /Downhill JudgmentThe actual acceleration calculated from the speed sensor signal is compared with the referenceacceleration 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 adownhill condition if the actual acceleration is greater than the reference acceleration, and restricts the4th upshift while traveling in 3rd. If a brake application is detected while traveling in 4th, it downshiftsto 3rd.


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 toinform the driver.

At the same time, the DTCs (Diagnosis Trouble Codes) are stored in memory. The DTCs can be read byconnecting 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 SignalDuring a speed sensor malfunction, the vehicle speed is detected throughsignals from the crankshaft position sensor and shift position signal tomaintain 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 faultysolenoid valve is cut off and control is achieved by operating the normalsolenoid valve.Shift control is opened as described in the table below, depending on thefailed solenoid.

Normal Solenoid Valve S1MalfunctioningSolenoid Valve S2

MalfunctioningBoth SolenoidMalfunctioning

Position SolenoidValve Gear

SolenoidValve Gear

SolenoidValve Gear

Gear when shiftslector is manually

S1 S2Gear

S1 S2Gear

S1 S2Gear slector is manually

operatedON OFF 1st x ON 3rd ON x 1st O/D

DON ON 2nd x ON 3rd OFF x O/D O/D

DOFF ON 3rd x ON 3rd OFF x O/D O/DOFF OFF O/D x OFF O/D OFF x O/D O/DON OFF 1st x ON 3rd ON x 1st O/D

2 ON ON 2nd x ON 3rd OFF x O/D O/DOFF ON 3rd x ON 3rd OFF x O/D O/D

LON OFF 1st x OFF 1st ON x 1st 1st

LON ON 2nd x ON 2nd ON x 1st 1st

x: Malfunctions


221CH29

Before Collision After Collision

BreakPortion

PlasticPortion

Impact

Break

172GN01

ECM

(d)

ODLPODMS

(c)

O/D OFFIndicatorLight

O/D Switch(Momentary Type)

O/D OFFIndicatorLight

O/DSwitch

IgnitionSwitch

ON

OFF

ON

OFF

ON

OFF

(d)

(b) (e)

(a) (a)

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, thismechanism causes the tip of the lever to break the plastic portion in order to dampen the impact.

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).


222CH02

Stop Light SwitchKey Lock Cable

Shift LockOverride Button

Shift Lock Unit Shift Lock Solenoid Shift Lock ECU

Shift Lock System

A shift lock system consists of the key interlock device and shift lock mechanism, that prevents theunintended 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.

Documents

Automatic A245E,A246E