AT-1
AUTOMATIC TRANSAXLE
C TRANSMISSION/TRANSAXLE
CONTENTS
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SECTION AT
A
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AT
AUTOMATIC TRANSAXLE
INDEX FOR DTC ........................................................ 5
Alphabetical Index .................................................... 5
PRECAUTIONS .......................................................... 6
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 6
Precautions Necessary for Steering Wheel Rotation
After Battery Disconnect .......................................... 6
Precautions .............................................................. 7
Service Notice or Precautions .................................. 8
PREPARATION ........................................................... 9
Special Service Tools ............................................... 9
Commercial Service Tools ...................................... 12
A/T FLUID ................................................................. 14
Checking A/T Fluid ................................................. 14
Changing A/T Fluid ................................................ 15
A/T CONTROL SYSTEM .......................................... 16
Cross-Sectional View ............................................. 16
Shift Mechanism ..................................................... 17
TCM Function ......................................................... 26
CAN Communication .............................................. 27
Input/Output Signal of TCM .................................... 27
Line Pressure Control ............................................ 28
Shift Control ........................................................... 29
Lock-up Control ...................................................... 30
Engine Brake Control (Overrun Clutch Control) ..... 31
Control Valve .......................................................... 33
TROUBLE DIAGNOSIS ............................................ 34
DTC Inspection Priority Chart ................................ 34
Fail-safe ................................................................. 34
How to Perform Trouble Diagnoses for Quick and
Accurate Repair ..................................................... 36
A/T Electrical Parts Location .................................. 41
Circuit Diagram ...................................................... 42
Inspections Before Trouble Diagnosis .................... 43
Road Test ............................................................... 48
Check Before Engine Is Started ............................. 48
Check at Idle .......................................................... 48
Cruise Test — Part 1 .............................................. 50
Cruise Test — Part 2 .............................................. 51Cruise Test — Part 3 .............................................. 52
Vehicle Speed Which Gear Shifting Occurs ........... 54
Vehicle Speed at When Lock-up Occurs/Releases ... 54
Symptom Chart ....................................................... 55
TCM Terminals and Reference Value ..................... 64
CONSULT-II Function (A/T) .................................... 67
Diagnostic Procedure Without CONSULT-II ........... 76
VEHICLE SPEED SENSOR·A/T (REVOLUTION
SENSOR) .................................................................. 80
Description .............................................................. 80
CONSULT-II Reference Value ................................ 80
On Board Diagnosis Logic ...................................... 80
Possible Cause ....................................................... 80
DTC Confirmation Procedure ................................. 80
Wiring Diagram — AT — VSSA/T .......................... 82
Diagnostic Procedure ............................................. 83
VEHICLE SPEED SENSOR MTR ............................. 86
Description .............................................................. 86
CONSULT-II Reference Value ................................ 86
On Board Diagnosis Logic ...................................... 86
Possible Cause ....................................................... 86
DTC Confirmation Procedure ................................. 86
Wiring Diagram — AT — VSSMTR ........................ 87
Diagnostic Procedure ............................................. 88
SHIFT SOLENOID VALVE A .................................... 90
Description .............................................................. 90
CONSULT-II Reference Value ................................ 90
On Board Diagnosis Logic ...................................... 90
Possible Cause ....................................................... 90
DTC Confirmation Procedure ................................. 90
Wiring Diagram — AT — SSV/A ............................. 91
Diagnostic Procedure ............................................. 92
Component Inspection ............................................ 94
SHIFT SOLENOID VALVE B .................................... 95
Description .............................................................. 95
CONSULT-II Reference Value ................................ 95
On Board Diagnosis Logic ...................................... 95
Possible Cause ....................................................... 95
DTC Confirmation Procedure ................................. 95
Wiring Diagram — AT — SSV/B ............................. 96
AT-3
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CONSULT-II Reference Value .............................. 167
Diagnostic Procedure ........................................... 167
TROUBLE DIAGNOSIS FOR SYMPTOMS ............ 168
Wiring Diagram — AT — NONDTC ...................... 168
A/T CHECK Indicator Lamp Does Not Come On . 173
Engine Cannot Be Started in “P” and “N” Position . 175
In “P” Position, Vehicle Moves Forward or Backward
When Pushed ....................................................... 176
In “N” Position, Vehicle Moves ............................. 176
Large Shock. “N” → “R” Position .......................... 177
Vehicle Does Not Creep Backward in “R” Position . 179
Vehicle Does Not Creep Forward in “D”, “3”, “2” or
“1” Position ........................................................... 181
Vehicle Cannot Be Started From D
1 ..................... 182
A/T Does Not Shift: D
1 → D2 or Does Not Kickdown:
D
4 → D2 ............................................................... 184
A/T Does Not Shift: D
2 → D3 ............................... 186
A/T Does Not Shift: D
3 → D4 ............................... 188
A/T Does Not Perform Lock-up ............................ 191
A/T Does Not Hold Lock-up Condition ................. 193
Lock-up Is Not Released ...................................... 195
Engine Speed Does Not Return To Idle (Light Brak-
ing D
4 → D3 ) ....................................................... 195
A/T Does Not Shift: D
4 → 33 , When A/T Selector
Lever “D” → “3” .................................................... 197
A/T Does Not Shift: 3
3 → 22 , When Selector Lever
“3” → “2” Position ................................................. 198
A/T Does Not Shift: 2
2 → 11 , When Selector Lever
“2” → “1” Position ................................................. 200
Vehicle Does Not Decelerate By Engine Brake (D
4
→ 3
3 ) ................................................................... 203
Vehicle Does Not Decelerate By Engine Brake (3
3
→ 2
2 ) ................................................................... 205
Vehicle Does Not Decelerate By Engine Brake (2
2
→ 1
1 ) ................................................................... 208
TCM Self-diagnosis Does Not Activate ................ 210
TRANSMISSION CONTROL MODULE ..................211
Removal and Installation ....................................... 211
SHIFT CONTROL SYSTEM ................................... 213
Control Device Removal and Installation ............. 213
Adjustment of A/T Position ................................... 215
Checking of A/T Position ...................................... 215
A/T SHIFT LOCK SYSTEM .................................... 216
Description ........................................................... 216
Shift Lock System Electrical Parts Location ......... 216
Wiring Diagram — AT — SHIFT ........................... 217
Shift Lock Control Unit Reference Values ............ 221
Component Inspection ......................................... 222
ON-VEHICLE SERVICE ......................................... 225
Control Valve Assembly and Accumulators .......... 225
Park/Neutral Position (PNP) Switch ..................... 230
Differential Side Oil Seal Replacement ................ 231
Revolution Sensor Replacement .......................... 233
Turbine Revolution Sensor (Power Train Revolution
Sensor) Replacement .......................................... 234
AIR BREATHER HOSE .......................................... 236
Removal and Installation [Air Breather Hose (Oil
Catch Tank to Air Duct)] ....................................... 236
Removal and Installation [Oil Catch Tank and Air Breather Hose (A/T assembly to Oil catch tank)] . 239
TRANSAXLE ASSEMBLY ......................................241
Removal and Installation ......................................241
OVERHAUL ............................................................246
Components .........................................................246
Oil Channel ...........................................................252
Locations of Adjusting Shims, Needle Bearings and
Thrust Washers ....................................................253
Locations of Snap Rings .......................................254
DISASSEMBLY .......................................................255
Disassembly .........................................................255
REPAIR FOR COMPONENT PARTS .....................272
Manual Shaft ........................................................272
Oil Pump ...............................................................275
Control Valve Assembly ........................................280
Control Valve Upper Body ....................................289
Control Valve Lower Body ....................................293
Reverse Clutch .....................................................296
High Clutch ...........................................................301
Forward and Overrun Clutches ............................307
Low & Reverse Brake ...........................................315
Rear Internal Gear, Forward Clutch Hub and Over-
run Clutch Hub ......................................................319
Output Shaft, Idler Gear, Reduction Pinion Gear and
Bearing Retainer ...................................................323
Band Servo Piston Assembly ...............................329
Final Drive ............................................................335
ASSEMBLY .............................................................339
Assembly (1) .........................................................339
Adjustment (1) ......................................................340
Assembly (2) .........................................................345
Adjustment (2) ......................................................352
Assembly (3) .........................................................355
SERVICE DATA AND SPECIFICATIONS (SDS) ....362
General Specifications ..........................................362
Vehicle Speed Which Gear Shifting Occurs .........362
Vehicle Speed at When Lock-up Occurs/Releases .362
Stall Revolution .....................................................363
Line Pressure .......................................................363
Adjusting shims, Needle Bearings, Thrust Washers
and Snap Rings ....................................................363
Control Valves ......................................................364
Accumulator ..........................................................365
Clutch and Brakes ................................................366
Final Drive ............................................................367
Planetary Carrier and Oil Pump ............................367
Input Shaft ............................................................367
Reduction Pinion Gear .........................................367
Band Servo ...........................................................368
Output Shaft .........................................................368
Bearing Retainer ...................................................368
Total End Play .......................................................368
Reverse Clutch End Play ......................................368
Removal and Installation ......................................368
Shift Solenoid Valves ............................................368
Solenoid Valves ....................................................368
A/T Fluid Temperature Sensor ..............................368
Revolution Sensor ................................................369
A/T CONTROL SYSTEM
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Shift MechanismBCS000ZO
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. Idler gear 24. Output gear
SAT998I
Clutch and brake components Abbr. Function
5Reverse clutch R/C To transmit input power to front sun gear 7 .
6High clutch H/C To transmit input power to front planetary carrier 10 .
15Forward clutch F/C To connect front planetary carrier 10 with forward one-way clutch 16 .
17Overrun clutch O/C To connect front planetary carrier 10 with rear internal gear 13 .
4Brake band B/B To lock front sun gear 7 .
16Forward one-way clutch F/O.CWhen forward clutch 15 is engaged, to stop rear internal gear 13 from rotating
in opposite direction against engine revolution.
18Low one-way clutch L/O.CTo stop front planetary carrier 10 from rotating in opposite direction against
engine revolution.
19Low & reverse brake L & R/B To lock front planetary carrier 10 .
AT-18
A/T CONTROL SYSTEM
CLUTCH AND BAND CHART
*1: 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.
*2: Oil pressure is applied to 4th “apply” side in condition *1 above, and brake band contracts.
: 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 posi-
tionR/C
5H/C
6F/C
15O/C
17Band servo
F/O.C
16L/O.C
18L&R/B
19Lock-
upRemarks
2nd
apply3rd
release4th
apply
PPA R K
POSITION
RREVERSE
POSITION
NNEUTRAL
POSITION
1st D B B
D2nd A BAutomatic
shift
3rd A *1C C B1 ⇔ 2 ⇔ 3
⇔ 4
4th C *2C C
31st D B B
Automatic
shift
1 ⇔ 2 ⇔ 3 2nd A B
3rd A *1C C B
21stBB
Automatic
shift
1 ⇔ 2 ⇐ 3 2ndB
3rd *1C C B
11stBB
Locks (held
stationary)
in 1st speed
1 ⇐ 2 ⇐ 3 2ndB
3rd *1C C B
AT-26
A/T CONTROL SYSTEM
TCM FunctionBCS000ZP
The function of the TCM is to:
Receive input signals sent from various switches and sensors.
Determine required line pressure, shifting point, lock-up operation, and engine brake operation.
Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SWITCHES & SENSORS
TCM
ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Turbine revolution sensor (power
train revolution sensor)
Vehicle speed signal
3rd position switch signal
Stop lamp switch signalShift control
Line pressure control
Lock-up control
Overrun clutch control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
control
CAN systemShift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
SCIA7869E
A/T CONTROL SYSTEM
AT-27
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CAN CommunicationBCS000ZQ
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer to LAN-49,
"CAN System Specification Chart" .
Input/Output Signal of TCMBCS000ZR
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: Used as a condition for starting self-diagnostics; if self-diagnostics are not started, it is judged that there is some kind of error.
*5: Input by CAN communications.
*6: Output by CAN communications.Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
functionSelf-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXX(*3) XX
Vehicle speed sensor A/T
(Revolution sensor)XXXXX(*3) XX
Vehicle speed sensor MTR
(*1)XXXX X
Closed throttle position signal
(*5)(*2) X(*2) XXX(*4) X
Wide open throttle position signal
(*5)(*2) X (*2) X (*4) X
Turbine revolution sensor (Power
train revolution sensor)XX X XX
Engine speed signal X X X X
PNP switch XXXXX(*3) X(*4) X
Stop lamp switch signal
(*5)XX (*4) X
A/T fluid temperature sensors X X X X X X
3rd position switch signal
(*5)XXXX (*4) X
TCM power supply voltage signal X X X X
Out-
putShift solenoid valve A/B X (*3) X X
Line pressure solenoid X (*3) X X
Torque converter clutch solenoid
valveX(*3) XX
Overrun clutch solenoid valve X X (*3) X X
A/T CHECK indicator lamp
(*6)X
AT-30
A/T CONTROL SYSTEM
CONTROL OF SHIFT VALVES A AND B
Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift
valves A and B.
The figure above shows the operation of shift valve B. When the shift solenoid valve is “ON”, pilot pressure
applied to the end face of the shift valve overcomes spring force, moving the valve upward.
Lock-up ControlBCS000ZU
The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip to
increase power transmission efficiency. The solenoid valve is controlled by an ON-OFF duty signal sent from
the TCM. The signal is converted to an oil pressure signal which controls the torque converter clutch piston.
CONDITIONS FOR LOCK-UP OPERATION
When vehicle is driven in 3rd and 4th gear position, vehicle speed and throttle opening are detected. If the
detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.
TORQUE CONVERTER CLUTCH SOLENOID VALVE CONTROL
Lock-up Control System Diagram
SAT009J
Selector lever “D” position “3” position
Gear position D
4 , D333
Vehicle speed sensor More than set value
accelerator pedal position sensor Less than set opening
Closed throttle position signal OFF
A/T fluid temperature sensor More than 20°C (68°F)
SCIA5623E
A/T CONTROL SYSTEM
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Lock-up Released
In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by drain-
ing the torque converter clutch piston applying pressure and the torque converter clutch piston release pres-
sure is generated.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
In the lock-up applied state, the torque converter clutch control valve is set into the locked state by generating
the torque converter clutch piston applying pressure and the torque converter clutch piston release pressure is
drained.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
The current output from the TCM to the torque converter clutch solenoid is varied to steadily increase the
torque converter clutch solenoid pressure.
In this way, the lock-up applying pressure gradually rises and while the torque converter clutch piston is put
into half-clutched status, the torque converter clutch piston applying pressure is increased and the coupling is
completed smoothly.
Engine Brake Control (Overrun Clutch Control)BCS000ZV
Forward one-way clutch is used to reduce shifting shocks in downshifting operations. This clutch transmits
engine torque to the wheels. However, drive force from the wheels is not transmitted to the engine because
the one-way clutch rotates idle. This means the engine brake is not effective.
The overrun clutch operates when the engine brake is needed.
OVERRUN CLUTCH OPERATING CONDITIONS
SCIA4831E
Selector lever position Gear position Throttle opening
“D” position D
1 , D2 , D3 gear position
Less than 3/16
“3” position 3
1 , 32 , 33 gear position
“2” position 2
1 , 22 gear position
At any position
“1” position 1
1 , 12 gear position