Principe u240e

CHASSIS – AUTOMATIC TRANSAXLE CH-23

�U240E AUTOMATIC TRANSAXLE

1. General

� The U240E is a compact, lightweight, and high-capacity 4-speed automatic transaxle [Super ECT(Electronically Controlled Transaxle)].

� High-precision clutch pressure control has been adopted in this automatic transaxle to attain high responseand smooth shifting.

� The basic construction and operation are the same as those on the ’02 Celica.

� Specification �

Transaxle Type U240E

Engine Type 2ZZ-GE

1st 3.943

2nd 2.197

Gear Ratio*1 3rd 1.413

4th 1.020

Reverse 3.145

Differential Gear Ratio 3.120

Fluid Capacity*2 Liters (US qts, Imp.qts) 7.4 (7.8, 6.5)

Fluid Type ATF Type T-IV

Dry Weight kg (lb.) 80.0 (176.4)

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

CHASSIS – AUTOMATIC TRANSAXLECH-24

222CH03

Front Planetary GearCounter Drive Gear

Input Shaft

Differential Drive Pinion

Counter Driven Gear

Under Drive (U/D)Planetary Gear

Rear Planetary Gear

F1

C2

B1 B2C1

C3

F2

B3

C1 Forward Clutch 4

C2 Direct Clutch 4

C3 U/D Direct ClutchThe No of Discs

3

B1 2nd BrakeThe No. of Discs

4

B2 2nd Brake 5

B3 1st & Reverse Brake 3

F1 No.1 One-Way ClutchThe No of Sprags

22

F2 U/D One-Way ClutchThe No. of Sprags

15

The No. of Sun Gear Teeth 43

Front Planetary Gear The No. of Pinion Gear Teeth 17y

The No. of Ring Gear Teeth 77


Rear Planetary Gear The No. of Pinion Gear Teeth 19y



U/D Planetary Gear The No. of Pinion Gear Teeth 26y



208CH02

Lock-upClutch

Turbine RunnerPump Impeller

Stator

OD Input Shaft

One-way Clutch

208CH03

Pump Body Drive Gear

Stator Shaft

Driven Gear

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.


Torque Converter Type3-Element, 1-Step, 2-Phase(with Lock-up Mechanism)

Stall Torque Ratio 1.8

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.


Gear Gear Teeth

Drive Gear 9

Driven Gear 11


208CH04

Rear Planetary Gear

Front Planetary Gear

Sun Gear

Counter Driven Gear

Ring Gear

Counter Drive Gear

Input Shaft

Intermediate Shaft

Sun Gear

U/D Planetary Gear

Differential DrivePinion

C2

B1 F1 B2 C1

F2 B3

C3

4. Planetary Gear Unit

Construction

� The counter drive and driven gears are placed in front of the front planetary gear and the under drive(U/D) planetary gear unit is placed above the counter shaft. Furthermore, the force transmission methodhas been changed by eliminating the brake and the one-way clutch. As a result, a torque capacity thataccommodates the high output engine has been attained, while keeping the gear unit compact.

� A centrifugal fluid pressure canceling mechanism has been adopted in the C2 and C3 clutches that areapplied when shifting from 2nd to 3rd and from 3rd to 4th.

Function of Component

Component Function

C1 Forward Clutch Connects input shaft and front planetary sun gear.

C2 Direct Clutch Connects input shaft and rear planetary sun gear.

C3 U/D Direct Brake Connects U/D sun gear and U/D planetary carrier.

B1 2nd BrakePrevents rear planetary sun gear from turning either clockwise orcounterclockwise.

B2 1st & Reverse BrakePrevents rear planetary carrier and front planetary ring gear fromturning either clockwise or counterclockwise.

B3 U/D BrakePrevents U/D sun gear from turning either clockwise orcounterclockwise.

F1 No.1 One-Way ClutchPrevents rear planetary carrier and front planetary ring gear fromturning counterclockwise.

F2 U/D One-Way Clutch Prevents U/D planetary sun gear from turning clockwise.

Planetary GearsThese gears change 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.


161ES09

1st Gear (D or 2 Position)

Rear Planetary Gear


Counter Drive Gear

Input Shaft

Intermediate ShaftSun Gear

U/D Planetary Gear

Sun Gear

Counter Driven Gear

DifferentialDrive Pinion

Ring Gear

C2

B1 F1 B2 C1

F2 B3

C3

Transaxle Power Flow

ShiftLever Gear

Solenoid ValveC C C B B B F FLever

PositionGear

SL1 SL2 S4 DSLC1 C2 C3 B1 B2 B3 F1 F2

P Park ON ON OFF OFF �

R Reverse ON OFF OFF OFF � � �

N Neutral ON ON OFF OFF �

1st ON ON OFF OFF � � � �

D2nd OFF ON OFF OFF � � � �

D3rd OFF/ON* OFF OFF OFF/ON* � � � �

4th OFF/ON* OFF ON OFF/ON* � � �

21st ON ON OFF OFF � � � �

22nd OFF ON OFF OFF � � � �

L 1st ON ON OFF ON � � � � �

*: Lock-up ON


161ES10

161ES11

161ES12

2nd Gear (D or 2 Position)

3rd Gear (D Position)

4th Gear (D Position)

Rear Planetary Gear


Counter Drive Gear

Input Shaft


U/D Planetary Gear

Sun Gear

Counter Driven Gear


Ring Gear

C2

B1F1 B2 C1

F2 B3

C3

Rear Planetary Gear


Counter Drive Gear

Input Shaft


U/D Planetary GearSun Gear

Counter Driven Gear


Ring Gear

C2

B1F1 B2 C1

F2 B3

C3

Rear Planetary Gear


Counter Drive Gear

Input Shaft


U/D Planetary Gear

Sun Gear

Counter Driven Gear


Ring Gear

C2

B1F1 B2 C1

F2 B3

C3


161ES13

Rear Planetary Gear


Counter Drive Gear

Input Shaft

Intermediate Shaft

Sun GearU/D Planetary Gear

Sun Gear

Counter Driven Gear

Ring Gear


C2

B1F1 B2 C1

C3

F2 B3

181CH66

Rear Planetary Gear

Front Planetary GearCounter Drive Gear

Input Shaft

Intermediate Shaft

Sun Gear

U/D Planetary Gear

Sun Gear

Counter Driven Gear

Ring Gear


C2

B1F1 B2 C1

C3

F2 B3

1st Gear (L Position)

Reverse Gear (R Position)


208CH05

Chamber A

Piston

C2 Clutch

Chamber B

C2 Clutch

C3 Clutch

157CH17

Target Fluid Pressure

Centrifugal Fluid Pressure Applied to Chamber A Clutch

Centrifugal Fluid Pressure Applied to Chamber B

Chamber B (Lubrication Fluid)

Shaft Side

Fluid Pressure Applied to Piston

Piston FluidPressure Chamber

Fluid pressure applied to piston

Centrifugal fluid pressure applied to chamber B

Target fluid pressure (original clutch pressure)

— =

Centrifugal Fluid Pressure Canceling Mechanism

There are two reasons for improving the conventional clutch mechanism:

� To prevent the generation of pressure by centrifugal force applied to the fluid in the piston fluid pressurechamber (hereafter referred to as “chamber A”) when the clutch is released, a check ball is provided.Therefore, before the clutch could be subsequently applied, it took time to fill chamber A.

� During shifting, in addition to the original clutch pressure that is controlled by the valve body, centrifugalpressure acts on the fluid in the chamber A exerting increased pressure depending on RPM.

To address these two needs for improvement, a canceling fluid pressure chamber (hereafter referred to as“chamber B”) has been provided opposite chamber A.

By utilizing the lubrication fluid such as that of the shaft, the same amount of centrifugal force is applied,thus canceling the centrifugal force that is applied to the piston itself. Accordingly, it is not necessary todischarge the fluid through the use of a check ball, and a highly responsive and smooth shiftingcharacteristic has been achieved.


181CH11

Solenoid Valve SL1Solenoid Valve SLT

Upper Valve Body

Plate

Fluid Temperature SensorLower Valve

BodySolenoid Valve S4

Solenoid Valve SL2

Solenoid Valve DSL

208CH06

Lock-up Relay ValveLock-up Control Valve

2nd Regulator ValveC2 Lock Valve

C2 Exhaust Check ValveClutch Apply Control ValveB1 Lock Valve

B3 Orifice Control Valve

Solenoid Modulator Valve

5. Valve Body Unit

General

� The valve body consists of the upper and lower valve bodies and 5 solenoid valves.

� Apply orifice control, which controls the flow volume to the B3 brake, has been adopted in this unit.

� Upper Valve Body �


208CH07

3-4 Shaft Valve

B1 Control ValveB2 Control Valve

Primary Regulator Valve

C2 Control Valve

� Lower Valve Body �

Function of Solenoid Valve

Solenoid Valve Action Function

SL1 For clutch and brake engagementpress re control

� B1 brake pressure control� Lock-up clutch pressure control

SL2pressure control

C2 clutch pressure control

SLT For line pressure control� Line pressure control� Secondary pressure control

S4 For 3-4 shift valve control Switches 3-4 shift valve

DSLFor B2 brake and lock-up clutchcontrol

� Controls B2 control valve via the C2lock valve

� Controls lock-up relay valve via theC2 lock valve


157CH19

Line Pressure

B3 Orifice Control Valve

Except 4th

B3 Brake ON

B3 Accumulator

B3 Apply Fluid Pressure

B3

Apply Orifice Control

This control is effected by the B3 orifice control valve. The B3 orifice control valve has been provided forthe B3 brake, which is applied when shifting from 4th to 3rd. The B3 orifice control valve is controlled bythe amount of the line pressure in accordance with shifting conditions, and the flow volume of the fluid thatis supplied to the B3 brake is controlled by varying the size of the control valve’s apply orifice.


6. Electronic Control System

General

The electronic control system of the U240E automatic transaxle consists of the controls listed below.

System Function

Clutch Pressure Control

� Controls the pressure that is applied directly to B1 brake and C2clutch by actuating the shift solenoid valve (SL1, SL2) inaccordance with ECM signals.

� The solenoid valves SL1 and SL2 minutely controls the clutchpressure in accordance with the engine output and drivingconditions.

Line PressureOptimal Control

Actuates the solenoid valve SLT to control the line pressure inaccordance with information from the ECM and the operatingconditions of the transaxle.

Engine Torque ControlRetards the engine ignition timing temporarily to improve shiftfeeling during up or down shifting.

Shift Control inUphill /Downhill Traveling(See Page CH-19 in the A246EAutomatic Transaxle)

Controls to restrict the 4th upshift or to provide appropriate enginebraking by using the ECM to determine whether the vehicle istraveling uphill or downhill.

Shift Timing ControlThe ECM sends current to the solenoid valve SL1 and/or SL2 basedon signals from each sensor and shifts the gear.

Lock-up Timing ControlThe ECM sends current to the shift solenoid valve (DSL) based onsignals from each sensor and engages or disengages the lockup clutch.

“N” to “D” Squat ControlWhen the shift lever is shifted from “N” to “D” position, the gear istemporarily shifted to 3rd and then to 1st to reduce vehicle squat.

Diagnosis

When the ECM detects a malfunction, the ECM makes a diagnosisand memorizes the failed section.

DiagnosisTo increase the speed for processing the signals, the 32-bit CPU of theECM has been adopted.

Fail-safeEven if a malfunction is detected in the sensors or solenoids, the ECMeffects fail-safe control to prevent the vehicle’s drivability from beingaffected significantly.


222CH04

SENSORS

CRANKSHAFT POSITIONSENSOR

ENGINE COOLANT TEMP.SENSOR

THROTTLE POSITION SENSOR

PARK/NEUTRAL POSITIONSWITCH

ABS SPEED SENSOR

SKID CONTROL ECU

COMBINATION METER

COUNTER GEAR SPEED SENSOR

INPUT TURBINE SPEED SENSOR

STOP LIGHT SWITCH

FLUID TEMPERATURE SENSOR

OVERDRIVE SWITCH

NE SOLENOID VALVE SL1

SOLENOID VALVE SL2

SOLENOID VALVE SLT

SOLENOID VALVE S4

SOLENOID VALVE DSL

MALFUNCTION INDICATOR LAMP

O/D OFF INDICATOR LIGHT

DATA LINK CONNECTOR 3

ECM

THW

VTA

NSW

R, D, 2, L

SPD

NC

NT

STP

THO

ODMS

SL1

SL2

SLT

S4

DSL

W

ODLP

SIL

TC, WFSE

ACTUATORS

Construction

The configuration of the electronic control system in the U240E automatic transaxle is as shown in thefollowing chart.


222CH05

O/D OFF Indicator Light MIL

DLC3Stop Light Switch

Overdrive Switch

ECMCounter Gear Speed Sensor

Park/Neutral Position Switch

Input Turbine Speed Sensor

Solenoid Valve SL1

Solenoid Valve SLT

Solenoid Valve SL2

Fluid Temp. Sensor

Solenoid Valve S4

Solenoid Valve DSL

Layout of Component


181CH14


Counter Gear Speed Sensor

Construction and Operation of Main Component

1) Fluid Temperature sensor

A fluid temperature sensor is installed in the valve body for direct detection of the fluid temperature.The fluid temperature sensor is used for adjusting clutch and brake pressures to keep the shift qualitysmooth.

2) Speed Sensors

The U240E automatic transaxle has adopted an input turbine speed sensor (for the NT signal) and acounter gear speed sensor (for the NC signal). Thus, the ECM can detect the timing of the shifting of thegears and appropriately control the engine torque and hydraulic pressure in response to the variousconditions.

� The input turbine speed sensor detects the input speed of the transaxle. The direct clutch (C2) drumis used as the timing rotor for this sensor.

� The counter gear speed sensor detects the speed of the counter gear. The counter drive gear is usedas the timing rotor for this sensor.


161ES15

Signals from Individual Sensors

ECM

SL1 SL2

B1 AccumulatorSolenoid Valve SL1 OFF

B1 Brake ON

B1 Control Valve

B1

C2 Accumulator

C2 Control Valve

Solenoid Valve SL2 OFF

C2 Clutch ON

C2

198CH32

Engine

Inpu

t S

haft

rpm Target rpm

Change Ratio

Practical rpm Change Ratio

Time Input Turbine Speed Sensor

ECM Signals from Various SensorEngine rpm

Engine Torque InformationFluid Temperature

SL2

SL1

Solenoid Drive Signal

TimeOut

put

Sha

ft To

rque

Clu

tch/

Bra

ke P

ress

ure

Clutch Pressure Control

1) Clutch to Clutch Pressure Control

This control has been adopted for shifting from the 1st to 2nd gear, and from the 2nd to 3rd gear.This actuates solenoid valves SL1 and SL2 in accordance with the signals from the ECM, and guides thisoutput pressure directly to the control valves B1 and C2 in order to regulate the line pressure that acts onthe B1 brake and C2 clutch.As a result, compact B1 and C2 accumulators without a back pressure chamber are realized.

2) Clutch Pressure Optimal Control

The ECM monitors the signals from various types of sensors such as the input turbine speed sensor,allowing shift solenoid valves SL1 and SL2 to minutely control the clutch pressure in accordance withengine output and driving conditions.Smooth shift characteristics are the result.


161ES26

Line Pressure

Primary Regulator

Fluid Pressure

Current

Pump Throttle Pressure

Solenoid Valve SLT

Solenoid Drive Signal

Trans-axle

Engine

ECM


Fluid Temperature

Shift Position

Throttle Valve OpeningIntake Air VolumeEngine Coolant TemperatureEngine rpm

Line Pressure Optimal Control

Through the use of the solenoid valve SLT, the line pressure is optimally controlled in accordance with theengine torque information, as well as with the internal operating conditions of the toque converter and thetransaxle.Accordingly, the line pressure can be controlled minutely in accordance with the engine output, drivingconditions, and the ATF temperature, thus achieving smooth shifts and optimizing the workload in the oilpump.


Service Tip

The length of time to clear the DTC by disconnecting the battery terminal has been changed from10 seconds to 1 minute.

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 operation when any abnormality occurs in a sensor or solenoid.

� Fail Safe List �

Malfunction Part Function

Speed SensorDuring a speed sensor malfunction, the vehicle speed is detectedthrough the signals from the counter gear speed sensor to effect normalcontrol.

Fluid Temp. Sensor During a fluid temp. sensor malfunction, 4th upshift is prohibited.

Counter Gear Speed SensorDuring a counter gear speed sensor malfunction, 4th upshift isprohibited.

Solenoid Valve SL1,SL2, and S4

The current to the failed solenoid valve is cut off and control is effectedby operating the other solenoid valves with normal operation.Shift control is effected as described in the table below, depending onthe failed solenoid.

When all solenoids are When shift solenoid SL1 is abnormalWhen SL2 is abnormal

When all solenoids arenormal Traveling 3rd or 4th Traveling 1st or 2nd

When SL2 is abnormal

SolenoidGear

SolenoidGear

SolenoidGear

SolenoidGear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

ON ON OFF 1st xON�

OFFOFF 3rd x* ON OFF 2nd

ON�

OFFx OFF 3rd

OFF ON OFF 2nd xON�

OFFOFF 3rd x* ON OFF 2nd OFF x OFF 3rd

OFF OFF OFF 3rd x OFF OFF 3rd x*OFF�

ON

OFF�

ON3rd OFF x

OFF�

ON3rd

OFF OFF ON 4th x OFF ON 4th x*OFF�

ONON 3rd OFF x ON 4th

*: B1 is constantly operating. (Continued)


When S4 is abnormalWhen SL1 and SL2 are When SL1 and S4 are abnormal

When S4 is abnormalabnormal Traveling 3rd or 4th Traveling 1st or 2nd

SolenoidGear

SolenoidGear

SolenoidGear

SolenoidGear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

ON ON x 1st x x OFF 3rd xON�

OFFx 3rd x ON x 2nd

OFF ON x 2nd x x OFF 3rd xON�

OFFx 3rd x ON x 2nd

OFF OFF x 3rd x x OFF 3rd xOFF�

ONx 3rd x

OFF�

ONx 2nd

OFF OFF x 4th x x ON 4th xOFF�

ONx 3rd x

OFF�

ONx 2nd

When SL2 and S4 areabnormal

When SL1, SL2 and S4 areabnormal

SolenoidGear

SolenoidGear

SL1 SL2 S4Gear

SL1 SL2 S4Gear

ON�

OFFx x 3rd x x x 3rd

OFF x x 3rd x x x 3rd



7. Shift Control Mechanism

� The overdrive switch is a momentary type.

� The 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 theimpact that is directed to the driver during a collision.

The basic construction and operation of the third item above are the same as those of the A246E automatictransaxle model. For details, see page CH-21 in the A246E Automatic Transaxle section.

Principe u240e

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