AT-4 Wiring Diagram — AT — TPS ..............................347
Diagnostic Procedure ...........................................348
SHIFT SOLENOID VALVE A ..................................350
Description ............................................................350
CONSULT-II Reference Value ..............................350
On Board Diagnosis Logic ....................................350
Possible Cause .....................................................350
DTC Confirmation Procedure ...............................350
Wiring Diagram — AT — SSV/A ...........................352
Diagnostic Procedure ...........................................353
Component Inspection ..........................................355
SHIFT SOLENOID VALVE B ..................................356
Description ............................................................356
CONSULT-II Reference Value ..............................356
On Board Diagnosis Logic ....................................356
DTC Confirmation Procedure ...............................356
Wiring Diagram — AT — SSV/B ...........................358
Diagnostic Procedure ...........................................359
Component Inspection ..........................................361
OVERRUN CLUTCH SOLENOID VALVE ...............362
Description ............................................................362
CONSULT-II Reference Value ..............................362
On Board Diagnosis Logic ....................................362
Possible Cause .....................................................362
DTC Confirmation Procedure ...............................362
Wiring Diagram — AT — OVRCSV ......................364
Diagnostic Procedure ...........................................365
Component Inspection ..........................................367
TORQUE CONVERTER CLUTCH SOLENOID
VALVE .....................................................................368
Description ............................................................368
CONSULT-II Reference Value ..............................368
On Board Diagnosis Logic ....................................368
Possible Cause .....................................................368
DTC Confirmation Procedure ...............................368
Wiring Diagram — AT — TCV ..............................370
Diagnostic Procedure ...........................................371
Component Inspection ..........................................373
BATT/FLUID TEMP SEN (A/T FLUID TEMP SEN-
SOR CIRCUIT AND TCM POWER SOURCE) ........374
Description ............................................................374
CONSULT-II Reference Value ..............................374
On Board Diagnosis Logic ....................................374
Possible Cause .....................................................374
DTC Confirmation Procedure ...............................375
Wiring Diagram — AT — BA/FTS .........................376
Diagnostic Procedure ...........................................377
Component Inspection ..........................................381
ENGINE SPEED SIGNAL .......................................382
Description ............................................................382
CONSULT-II Reference Value ..............................382
On Board Diagnosis Logic ....................................382
DTC Confirmation Procedure ...............................382
Wiring Diagram — AT — ENGSS .........................383
Diagnostic Procedure ...........................................384
LINE PRESSURE SOLENOID VALVE ...................387
Description ............................................................387
CONSULT-II Reference Value ..............................387
On Board Diagnosis Logic ....................................387Possible Cause .....................................................387
DTC Confirmation Procedure ................................387
Wiring Diagram — AT — LPSV ............................389
Diagnostic Procedure ............................................390
Component Inspection ..........................................393
MAIN POWER SUPPLY AND GROUND CIRCUIT .394
Description ............................................................394
On Board Diagnosis Logic ....................................394
Possible Cause .....................................................394
DTC Confirmation Procedure ................................394
Wiring Diagram — AT — MAIN .............................395
Diagnostic Procedure ............................................396
A/T SHIFT LOCK SYSTEM .....................................398
Description ............................................................398
Shift Lock System Electrical Parts Location ..........398
Wiring Diagram — SHIFT .....................................399
Diagnostic Procedure ............................................400
KEY INTERLOCK CABLE ......................................402
Components ..........................................................402
Removal ................................................................402
Installation .............................................................403
ON-VEHICLE SERVICE ..........................................404
Control Valve Assembly and Accumulators ..........404
Park/Neutral Position (PNP) Switch ......................408
Differential Side Oil Seal Replacement .................410
Revolution Sensor Replacement ..........................412
REMOVAL AND INSTALLATION ............................413
Removal ................................................................413
Installation .............................................................415
OVERHAUL .............................................................416
Components ..........................................................416
Oil Channel ...........................................................422
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................423
DISASSEMBLY .......................................................424
Disassembly ..........................................................424
REPAIR FOR COMPONENT PARTS ......................440
Manual Shaft .........................................................440
Oil Pump ...............................................................443
Control Valve Assembly ........................................448
Control Valve Upper Body .....................................457
Control Valve Lower Body .....................................461
Reverse Clutch .....................................................464
High Clutch ...........................................................469
Forward and Overrun Clutches .............................475
Low & Reverse Brake ...........................................483
Rear Internal Gear, Forward Clutch Hub and Over-
run Clutch Hub ......................................................487
Output Shaft, Idler Gear, Reduction Pinion Gear and
Bearing Retainer ...................................................491
Band Servo Piston Assembly ................................497
Final Drive .............................................................503
ASSEMBLY .............................................................507
Assembly (1) .........................................................507
Adjustment (1) .......................................................508
Assembly (2) .........................................................513
Adjustment (2) .......................................................520
Assembly (3) .........................................................523
AT-22
OVERALL SYSTEM
Shift MechanismECS004QD
CONSTRUCTION
FUNCTION OF CLUTCH AND BRAKE
1. Torque converter 2. Oil pump 3. Input shaft
4. Brake band 5. Reverse clutch 6. High clutch
7. Front sun gear 8. Front pinion gear 9. Front internal gear
10. Front planetary carrier 11. Rear sun gear 12. Rear pinion gear
13. Rear internal gear 14. Rear planetary carrier 15. Forward clutch
16. Forward one-way clutch 17. Overrun clutch 18. Low one-way clutch
19. Low & reverse brake 20. Parking pawl 21. Parking gear
22. Output shaft 23. Idle gear 24. Output gear
SAT998I
Clutch and brake components Abbr. Function
5 Reverse clutch R/C To transmit input power to front sun gear 7 .
6 High clutch H/C To transmit input power to front planetary carrier 10 .
15 Forward clutch F/C To connect front planetary carrier 10 with forward one-way clutch 16 .
17 Overrun clutch O/C To connect front planetary carrier 10 with rear internal gear 13 .
4 Brake band B/B To lock front sun gear 7 .
16 Forward one-way clutch F/O.C When forward clutch 15 is engaged, to stop rear internal gear 13 from rotating in
opposite direction against engine revolution.
18 Low one-way clutch L/O.C To stop front planetary carrier 10 from rotating in opposite direction against
engine revolution.
19 Low & reverse brake L & R/B To lock front planetary carrier 10 .
OVERALL SYSTEM
AT-23
D
E
F
G
H
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B
AT
CLUTCH AND BAND CHART
*1: Operates when overdrive control switch is set in “OFF” position.
*2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not con-
tract because oil pressure area on the “release” side is greater than that on the “apply” side.
*3: Oil pressure is applied to 4th “apply” side in condition *2 above, and brake band contracts.
*4: A/T will not shift to 4th when overdrive control switch is set in “OFF” position.
: Operates.
A: Operates when throttle opening is less than 3/16, activating engine brake.
B: Operates during “progressive” acceleration.
C: Operates but does not affect power transmission.
D: Operates when throttle opening is less than 3/16, but does not affect engine brake. Shift positionRever
se
clutch
5High
clutch
6For-
ward
clutch
15Over-
run
clutch
17Band servo
Forward
one-way
clutch
16Low
one-
way
clutch
18Low &
revers
e
brake
19Lock-
upRemarks
2nd
apply3rd
releas
e4th
apply
PPA R K
POSITION
RREVERSE
POSITION
NNEUTRAL
POSITION
D*41st *1D B B
Automatic
shift
1 ⇔ 2 ⇔ 3 ⇔
4 2nd *1A B
3rd *1A *2C C B
*1
4th C *3C C
21stBB
Automatic
shift
1 ⇔ 2⇐3 2ndB
3rd *2C C B
11stB
Locks (held
stationary) in
1st speed
1 ⇐ 2⇐3 2ndB
3rd *2C C B
OVERALL SYSTEM
AT-39
D
E
F
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B
AT
Control ValveECS004QG
FUNCTION OF CONTROL VALVES
Valve name Function
Pressure regulator valve, plug and sleeve
plugRegulates oil discharged from the oil pump to provide optimum line pressure for all driv-
ing conditions.
Pressure modifier valve and sleeve Used as a signal supplementary valve to the pressure regulator valve. Regulates pres-
sure-modifier pressure (signal pressure) which controls optimum line pressure for all
driving conditions.
Pilot valve Regulates line pressure to maintain a constant pilot pressure level which controls lock-up
mechanism, overrun clutch, shift timing.
Accumulator control valve Regulates accumulator back-pressure to pressure suited to driving conditions.
Manual valve Directs line pressure to oil circuits corresponding to select positions.
Hydraulic pressure drains when the shift lever is in Neutral.
Shift valve A Simultaneously switches three oil circuits using output pressure of shift solenoid valve A
to meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th →
3rd → 2nd → 1st gears) in combination with shift valve B.
Shift valve B Simultaneously switches two oil circuits using output pressure of shift solenoid valve B in
relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and upshifting (1st → 2nd → 3rd → 4th gears/4th →
3rd → 2nd → 1st gears) in combination with shift valve A.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simultaneously
with application of the brake band in D
4 . (Interlocking occurs if the overrun clutch
engages during D
4 .)
1st reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when downshift-
ing from the 1st position 1
2 to 11 .
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In the 1st and 2nd positions, line pressure acts on the overrun clutch reducing valve to
increase the pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control valve, plug
and sleeveActivates or inactivates the lock-up function.
Also provides smooth lock-up through transient application and release of the lock-up
system.
1-2 accumulator valve and piston Lessens the shock find when the 2nd gear band servo contracts, and provides smooth
shifting.
3-2 timing valve Switches the pace that oil pressure is released depending on vehicle speed; maximizes
the high clutch release timing, and allows for soft downshifting.
Shuttle valve Determines if the overrun clutch solenoid valve should control the 3-2 timing valve or the
overrun clutch control valve and switches between the two.
Cooler check valve At low speeds and with a small load when a little heat is generated, saves the volume of
cooler flow, and stores the oil pressure for lock-up.
TROUBLE DIAGNOSIS — BASIC INSPECTION
AT-65
[EURO-OBD]
D
E
F
G
H
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L
MA
B
AT
Stall TestECS004QR
STALL TEST PROCEDURE
1. Check A/T fluid and engine oil levels. If necessary, add.
2. Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature. Refer to AT- 1 6 , "
Checking A/T Fluid" .
3. Set parking brake and block wheels.
4. Install a tachometer where it can be seen by driver during test.
It is good practice to mark the point of specified engine
rpm on indicator.
5. Start engine, apply foot brake, and place selector lever in D
position.
6. Accelerate to wide open throttle gradually while applying foot
brake.
7. Quickly note the engine stall revolution and immediately release
throttle.
During test, never hold throttle wide open for more than 5
seconds.
SAT647B
SAT513G
SAT775B
Stall revolution:
QR20DE: 2,450 - 2,950 rpm
QR25DE: 2,300 - 2,750 rpm
SAT514G
AT-68
[EURO-OBD]
TROUBLE DIAGNOSIS — BASIC INSPECTION
Line Pressure TestECS004QS
LINE PRESSURE TEST PORTS
Location of line pressure test ports are shown in the illustration.
Always replace pressure plugs as they are self-sealing
bolts.
LINE PRESSURE TEST PROCEDURE
1. Check A/T fluid and engine oil levels. If necessary, add fluid or
oil.
2. Drive vehicle for approx. 10 minutes or until engine oil and ATF
reach operating temperature. Refer to AT- 1 6 , "
Checking A/T
Fluid" .
3. Install pressure gauge to corresponding line pressure port.
4. Set parking brake and block wheels.
Continue to depress brake pedal fully while line pressure
test is being performed at stall speed.
SCIA0709E
SAT647B
UAT008
SAT513G
TROUBLE DIAGNOSIS — BASIC INSPECTION
AT-69
[EURO-OBD]
D
E
F
G
H
I
J
K
L
MA
B
AT
5. Start engine and measure line pressure at idle and stall speed.
When measuring line pressure at stall speed, follow the
stall test procedure.
LINE PRESSURE
JUDGEMENT OF LINE PRESSURE TEST
SAT493G
Check lock-up hold.Line pressure kPa (bar, kg/cm2 , psi)
“D”, “2” and “1” positions “R” position
Idle 500 (5.00, 5.1, 73) 778 (7.78, 7.9, 113)
Stall 1,233 (12.33, 12.6, 179) 1,918 (19.18, 19.6, 278)
Judgement Suspected parts
At idleLine pressure is low in all positions.
Oil pump wear
Control piston damage
Pressure regulator valve or plug sticking
Spring for pressure regulator valve damaged
Fluid pressure leakage between oil strainer and pressure regulator valve
Clogged strainer
Line pressure is low in particular posi-
tion.
Fluid pressure leakage between manual valve and particular clutch
For example, line pressure is:
− Low in “R” and “1” positions, but
− Normal in “D” and “2” positions.
Therefore, fluid leakage exists at or around low and reverse brake circuit.
Refer to AT- 2 3
.
Line pressure is high.
Maladjustment of throttle position sensor
A/T fluid temperature sensor damaged
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure modifier valve sticking
Pressure regulator valve or plug sticking
Open in dropping resistor circuit
At stall
speedLine pressure is low.
Maladjustment of throttle position sensor
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure regulator valve or plug sticking
Pressure modifier valve sticking
Pilot valve sticking
AT-78
[EURO-OBD]
TROUBLE DIAGNOSIS — BASIC INSPECTION
Cruise Test — Part 1
1. CHECK STARTING GEAR (D1 ) POSITION
1. Drive vehicle for approximately 10 minutes to warm engine oil and ATF up to operating temperature.
2. Park vehicle on flat surface.
3. Set overdrive control switch to ON position.
4. Move selector lever to “P” position.
5. Start engine.
6. Move selector lever to “D” position.
7. Accelerate vehicle by constantly depressing accelerator pedal
half-way.
Read gear position. Refer to AT- 4 6 , "
DATA MONITOR
MODE (A/T)" .
Does vehicle start from D
1 ?
YES >> GO TO 2.
NO >>
Mark the box on the “DIAGNOSTIC WORKSHEET”.
Refer to AT- 5 8
.
GO TO AT- 2 1 4 , "Vehicle Cannot Be Started From D1"
.
Continue “Road Test”. ATF operating temperature: 50 - 80°C (122 - 176°F)
SAT774B
SAT775B
SAT495G