AUTOMATIC TRANSMISSION
SECTION
AT
CONTENTS
PREPARATION AND PRECAUTIONS............................3
Special Service Tools ..................................................3
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER²...............4
Precautions ..................................................................4
Service Notice or Precautions .....................................5
OVERALL SYSTEM........................................................6
A/T Electrical Parts Location .......................................6
Wiring Diagram - A/T -.................................................7
Cross-sectional View ...................................................8
Hydraulic Control Circuits ............................................9
Shift Mechanism ........................................................10
Control System ..........................................................12
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................14
Self-diagnosis ............................................................14
Diagnosis by CONSULT-II .........................................20
TROUBLE DIAGNOSIS - Introduction........................22
Introduction ................................................................22
Diagnostic Worksheet ................................................23
Work Flow ..................................................................26
TROUBLE DIAGNOSIS - Basic Inspection................27
A/T Fluid Check .........................................................27
Stall Test ....................................................................27
Line Pressure Test .....................................................30
Road Test...................................................................32
TROUBLE DIAGNOSIS - General Description...........43
Symptom Chart ..........................................................43
TCM Terminals and Reference Value........................46
TROUBLE DIAGNOSIS FOR VHCL SPEED
SEN×A/T.........................................................................49
Wiring Diagram - AT - VSSA/T ..................................49
Vehicle Speed Sensor×A/T (Revolution sensor) ........50
TROUBLE DIAGNOSIS FOR VHCL SPEED
SEN×MTR.......................................................................52
Wiring Diagram - AT - VSSMTR ................................52
Vehicle Speed Sensor×MTR ......................................54TROUBLE DIAGNOSIS FOR THROTTLE POSI
SEN................................................................................56
Wiring Diagram - AT - TPS ........................................56
Throttle (Accelerator) Position Sensor ......................60
TROUBLE DIAGNOSIS FOR SHIFT SOLENOID/V
A.....................................................................................62
Wiring Diagram - AT - SSV/A ....................................62
Shift Solenoid Valve A ...............................................63
TROUBLE DIAGNOSIS FOR SHIFT SOLENOID/V
B.....................................................................................65
Wiring Diagram - AT - SSV/B ....................................65
Shift Solenoid Valve B ...............................................66
TROUBLE DIAGNOSIS FOR OVERRUN CLUTCH
S/V..................................................................................68
Wiring Diagram - AT - OVRCSV................................68
Overrun Clutch Solenoid Valve .................................69
TROUBLE DIAGNOSIS FOR T/C CLUTCH SOL/V.....71
Wiring Diagram - AT - TCV........................................71
Torque Converter Clutch Solenoid Valve ..................72
TROUBLE DIAGNOSIS FOR BATT/FLUID TEMP
SEN................................................................................75
Wiring Diagram - AT - BA/FTS ..................................75
A/T Fluid Temperature Sensor and TCM Power
Source........................................................................76
TROUBLE DIAGNOSIS FOR ENGINE SPEED SIG....79
Wiring Diagram - AT - ENGSS ..................................79
Engine Speed Signal .................................................80
TROUBLE DIAGNOSIS FOR LINE PRESSURE
S/V..................................................................................82
Wiring Diagram - AT - LPSV......................................82
Line Pressure Solenoid Valve ...................................84
TROUBLE DIAGNOSIS FOR NON-DETECTABLE
ITEMS.............................................................................87
Wiring Diagram - AT - PNP/SW.................................87
Park/neutral Position, Overdrive Control or
Throttle (Accelerator) Position Switches ...................88
DIAGNOSTIC PROCEDURES FOR SYMPTOMS........94
1. SPORT Indicator Lamp Does Not Come On ........94
2. SPORT or SNOW Indicator Lamp Does Not
Come On...................................................................95
3. O/D OFF Indicator Lamp Does Not Come On......95
4. SPORT Indicator Lamp Does Not Come On ........96
5. Engine Cannot Be Started In²P²and²N²
Position......................................................................97
6. In²P²Position, Vehicle Moves Forward Or
Backward When Pushed...........................................97
7. In²N²Position, Vehicle Moves .............................98
8. Large Shock.²N²->²R²Position .........................99
9. Vehicle Does Not Creep Backward In²R²
Position....................................................................100
10. Vehicle Does Not Creep Forward In²D²,²2²
Or²1²Position.........................................................101
11. Vehicle Cannot Be Started From D
1.................102
12. A/T Does Not Shift: D
1-> D2Or Does Not
Kickdown: D
4-> D2..................................................103
13. A/T Does Not Shift: D
2-> D3............................104
14. A/T Does Not Shift: D
3-> D4.............................105
15. A/T Does Not Perform Lock-up .........................106
16. A/T Does Not Hold Lock-up Condition ..............107
17. Lock-up Is Not Released ...................................107
18. Engine Speed Does Not Return To Idle (Light
Braking D
4-> D3) .....................................................108
19. Vehicle Does Not Start From D
1.......................109
20. A/T Does Not Shift: D
2-> D1When
Depressing Accelerator Pedal................................. 110
21. A/T Does Not Shift: D
4-> D3, When
Overdrive Control Switch²ON²->²OFF²............... 111
22. A/T Does Not Shift: D
3-> 22, When Selector
Lever²D²->²2²Position......................................... 111
23. A/T Does Not Shift: 2
2-> 11, When Selector
Lever²2²->²1²Position ......................................... 112
24. Vehicle Does Not Decelerate By Engine
Brake........................................................................ 112
ON-VEHICLE SERVICE.............................................. 113Control Valve Assembly and Accumulators ............. 113
Revolution Sensor Replacement ............................. 114
Rear Oil Seal Replacement ..................................... 114
Parking Components Inspection.............................. 114
Park/neutral Position Switch Adjustment ................. 114
Manual Control Linkage Adjustment........................ 115
REMOVAL AND INSTALLATION................................ 116
Removal ................................................................... 116
Installation ................................................................ 117
MAJOR OVERHAUL................................................... 119
Oil Channel ..............................................................121
Locations of Needle Bearings, Thrust Washers
and Snap Rings .......................................................122
DISASSEMBLY............................................................123
Disassembly.............................................................123
REPAIR FOR COMPONENT PARTS..........................134
Oil Pump ..................................................................134
Control Valve Assembly ...........................................138
Control Valve Upper Body .......................................144
Control Valve Lower Body .......................................149
Reverse Clutch ........................................................151
High Clutch ..............................................................155
Forward and Overrun Clutches ...............................157
Low & Reverse Brake..............................................161
Forward Clutch Drum Assembly ..............................165
Rear Internal Gear and Forward Clutch Hub ..........168
Band Servo Piston Assembly ..................................171
Parking Pawl Components ......................................175
ASSEMBLY..................................................................177
Assembly (1) ............................................................177
Adjustment ...............................................................185
Assembly (2) ............................................................188
A/T FLUID COOLER SYSTEM...................................195
A/T Fluid Cooler.......................................................195
SERVICE DATA AND SPECIFICATIONS (SDS)........196
General Specifications .............................................196
Specifications and Adjustment.................................196
When you read wiring diagrams:
IRead GI section, ªHOW TO READ WIRING DIAGRAMSº.
ISee EL section, ªPOWER SUPPLY ROUTINGº for power distribution circuit.
When you perform trouble diagnoses, read GI section, ªHOW TO FOLLOW FLOW CHART IN
TROUBLE DIAGNOSESº and ªHOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRI-
CAL INCIDENTº.
CONTENTS(Cont'd)
AT- 2
Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
The Supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger in a frontal collision.
The SRS system composition which is available to NISSAN MODEL R20 is as follows (The composition var-
ies according to the destination.):
Driver air bag module (located in the center of the steering wheel), front passenger air bag module (located
on the instrument panel on passenger side), seat belt pre-tensioner, a diagnosis sensor unit, warning lamp,
wiring harness and spiral cable.
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
ITo avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized NISSAN dealer.
IImproper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation either just before
the harness connectors or for the complete harness are related to the SRS.
Precautions
IBefore proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to
prevent the internal parts from becoming contaminated by dirt or other foreign matter.
IDisassembly should be done in a clean work area.
IUse lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could inter-
fere with the operation of the transmission.
IPlace disassembled parts in order for easier and proper assembly.
IAll parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.
IGaskets, seals and O-rings should be replaced any time the transmission is disassembled.
IIt is very important to perform functional tests whenever they are indicated.
IThe valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place removed parts in a parts rack in order to replace them in correct positions and sequences. Care will
also prevent springs and small parts from becoming scattered or lost.
IProperly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
IBefore assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, and to hold bearings and washers in place during assembly. Do not use grease.
IExtreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
IAfter overhaul, refill the transmission with new ATF.
IWhen the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque
converter and ATF cooling system.
Always follow the procedures under ªChanging A/T Fluidº in the MA section when changing A/T fluid.
PREPARATION AND PRECAUTIONS
AT- 4
Wiring Diagram Ð A/T Ð
YAT260
OVERALL SYSTEM
AT- 7
Introduction
The TCM receives a signal from the vehicle-speed sensor, throttle
(accelerator) position sensor or park/neutral position switch and
provides shift control or lock-up control via solenoid valves.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good
operating condition and be free of valve seizure, solenoid valve
malfunction, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the ªWork Flowº. Refer to AT-26.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A ªDiagnostic Worksheetº like the
example (AT-24) should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
SAT631IA
SAT632I
SEF234G
TROUBLE DIAGNOSIS Ð Introduction
AT-22
Wiring Diagram Ð AT Ð VSSA/T
YAT262
TROUBLE DIAGNOSIS FOR VHCL SPEED SEN×A/T
AT-49
Wiring Diagram Ð AT Ð VSSMTR
LHD MODELS
YAT263
TROUBLE DIAGNOSIS FOR VHCL SPEED SEN×MTR
AT-52
RHD MODELS
YAT264
TROUBLE DIAGNOSIS FOR VHCL SPEED SEN×MTR
Wiring Diagram Ð AT Ð VSSMTR (Cont'd)
AT-53