2005 INFINITI QX4 diagram

AT-1
AUTOMATIC TRANSMISSION
C TRANSMISSION/TRANSAXLE
CONTENTS
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Revision: October 20052005 QX56 INDEX FOR DTC ........................................................ 5
Alphabetical Index .................................................... 5
DTC No. Index ......................................................... 6
PRECAUTIONS .......................................................... 7
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 7
Precautions for On Board Diagnostic (OBD) System
of A/T and Engine .................................................... 7
Precautions .............................................................. 8
Service Notice or Precautions .................................. 9
Wiring Diagrams and Trouble Diagnosis .................. 9
PREPARATION ......................................................... 10
Special Service Tools ............................................. 10
Commercial Service Tools ...................................... 12
A/T FLUID ................................................................. 13
Changing A/T Fluid ................................................ 13
Checking A/T Fluid ................................................. 13
A/T Fluid Cooler Cleaning ...................................... 13
A/T CONTROL SYSTEM .......................................... 16
Cross-Sectional View (2WD models) ..................... 16
Cross-Sectional View (4WD models) ..................... 17
Shift Mechanism ..................................................... 18
TCM Function ......................................................... 29
CAN Communication .............................................. 30
Input/Output Signal of TCM .................................... 30
Line Pressure Control ............................................ 31
Shift Control ........................................................... 32
Lock-up Control ...................................................... 33
Engine Brake Control ............................................. 35
Control Valve .......................................................... 35
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 37
Introduction ............................................................ 37
OBD-II Function for A/T System ............................. 37
One or Two Trip Detection Logic of OBD-II ............ 37
OBD-II Diagnostic Trouble Code (DTC) ................. 37
Malfunction Indicator Lamp (MIL) ........................... 40
TROUBLE DIAGNOSIS ............................................ 41
DTC Inspection Priority Chart ................................ 41
Fail-Safe ................................................................. 41How To Perform Trouble Diagnosis For Quick and
Accurate Repair ...................................................... 43
A/T Electrical Parts Location .................................. 48
Circuit Diagram ....................................................... 49
Inspections Before Trouble Diagnosis .................... 50
Check Before Engine is Started .............................. 54
Check at Idle ........................................................... 54
Cruise Test - Part 1 ................................................. 55
Cruise Test - Part 2 ................................................. 57
Cruise Test - Part 3 ................................................. 58
Vehicle Speed When Shifting Gears ...................... 59
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................. 59
Vehicle Speed When Performing and Releasing
Slip Lock-up ............................................................ 59
Symptom Chart ....................................................... 60
TCM Input/Output Signal Reference Values ........... 82
CONSULT-II Function (A/T) .................................... 83
DTC U1000 CAN COMMUNICATION LINE .............. 95
Description .............................................................. 95
On Board Diagnosis Logic ...................................... 95
Possible Cause ....................................................... 95
DTC Confirmation Procedure ................................. 95
Wiring Diagram — AT — CAN ................................ 96
Diagnostic Procedure ............................................. 98
DTC P0615 START SIGNAL CIRCUIT ..................... 99
Description .............................................................. 99
CONSULT-II Reference Value ................................ 99
On Board Diagnosis Logic ...................................... 99
Possible Cause ....................................................... 99
DTC Confirmation Procedure ................................. 99
Wiring Diagram — AT — STSIG ..........................100
Diagnostic Procedure ...........................................101
DTC P0700 TCM .....................................................103
Description ............................................................103
On Board Diagnosis Logic ....................................103
Possible Cause .....................................................103
DTC Confirmation Procedure ...............................103
Diagnostic Procedure ...........................................103
DTC P0705 PARK/NEUTRAL POSITION SWITCH .104

AT-2Revision: October 20052005 QX56 Description ............................................................104
CONSULT-II Reference Value ..............................104
On Board Diagnosis Logic ....................................104
Possible Cause .....................................................104
DTC Confirmation Procedure ...............................104
Wiring Diagram — AT — PNP/SW .......................105
Diagnostic Procedure ...........................................106
DTC P0720 VEHICLE SPEED SENSOR A/T (REV-
OLUTION SENSOR) ...............................................108
Description ............................................................108
CONSULT-II Reference Value ..............................108
On Board Diagnosis Logic ....................................108
Possible Cause .....................................................108
DTC Confirmation Procedure ...............................108
Wiring Diagram — AT — VSSA/T .........................110
Diagnostic Procedure ........................................... . 111
DTC P0725 ENGINE SPEED SIGNAL ...................113
Description ............................................................113
CONSULT-II Reference Value ..............................113
On Board Diagnosis Logic ....................................113
Possible Cause .....................................................113
DTC Confirmation Procedure ...............................113
Diagnostic Procedure ...........................................113
DTC P0740 TORQUE CONVERTER CLUTCH
SOLENOID VALVE .................................................115
Description ............................................................115
CONSULT-II Reference Value ..............................115
On Board Diagnosis Logic ....................................115
Possible Cause .....................................................115
DTC Confirmation Procedure ...............................115
Diagnostic Procedure ...........................................116
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP) .117
Description ............................................................117
CONSULT-II Reference Value ..............................117
On Board Diagnosis Logic ....................................117
Possible Cause .....................................................117
DTC Confirmation Procedure ...............................117
Diagnostic Procedure ...........................................118
DTC P0745 LINE PRESSURE SOLENOID VALVE .119
Description ............................................................119
CONSULT-II Reference Value ..............................119
On Board Diagnosis Logic ....................................119
Possible Cause .....................................................119
DTC Confirmation Procedure ...............................119
Diagnostic Procedure ...........................................120
DTC P1702 TRANSMISSION CONTROL MODULE
(RAM) ......................................................................121
Description ............................................................121
On Board Diagnosis Logic ....................................121
Possible Cause .....................................................121
DTC Confirmation Procedure ...............................121
Diagnostic Procedure ...........................................121
DTC P1703 TRANSMISSION CONTROL MODULE
(ROM) ......................................................................122
Description ............................................................122
On Board Diagnosis Logic ....................................122
Possible Cause .....................................................122
DTC Confirmation Procedure ...............................122
Diagnostic Procedure ...........................................122DTC P1705 THROTTLE POSITION SENSOR ........ 123
Description ............................................................ 123
CONSULT-II Reference Value ............................... 123
On Board Diagnosis Logic .................................... 123
Possible Cause ..................................................... 123
DTC Confirmation Procedure ................................ 123
Diagnostic Procedure ............................................ 123
DTC P1710 A/T FLUID TEMPERATURE SENSOR
CIRCUIT .................................................................. 126
Description ............................................................ 126
CONSULT-II Reference Value ............................... 126
On Board Diagnosis Logic .................................... 126
Possible Cause ..................................................... 126
DTC Confirmation Procedure ................................ 126
Wiring Diagram — AT — FTS ............................... 127
Diagnostic Procedure ............................................ 128
Component Inspection .......................................... 129
DTC P1716 TURBINE REVOLUTION SENSOR .... 131
Description ............................................................ 131
CONSULT-II Reference Value ............................... 131
On Board Diagnosis Logic .................................... 131
Possible Cause ..................................................... 131
DTC Confirmation Procedure ................................ 131
Diagnostic Procedure ............................................ 132
DTC P1721 VEHICLE SPEED SENSOR MTR ....... 133
Description ............................................................ 133
CONSULT-II Reference Value ............................... 133
On Board Diagnosis Logic .................................... 133
Possible Cause ..................................................... 133
DTC Confirmation Procedure ................................ 133
Diagnostic Procedure ............................................ 134
DTC P1730 A/T INTERLOCK ................................. 135
Description ............................................................ 135
On Board Diagnosis Logic .................................... 135
Possible Cause ..................................................... 135
DTC Confirmation Procedure ................................ 135
Judgement of A/T Interlock ................................... 136
Diagnostic Procedure ............................................ 136
DTC P1731 A/T 1ST ENGINE BRAKING ............... 138
Description ............................................................ 138
CONSULT-II Reference Value ............................... 138
On Board Diagnosis Logic .................................... 138
Possible Cause ..................................................... 138
DTC Confirmation Procedure ................................ 138
Diagnostic Procedure ............................................ 139
DTC P1752 INPUT CLUTCH SOLENOID VALVE .. 140
Description ............................................................ 140
CONSULT-II Reference Value ............................... 140
On Board Diagnosis Logic .................................... 140
Possible Cause ..................................................... 140
DTC Confirmation Procedure ................................ 140
Diagnostic Procedure ............................................ 141
DTC P1754 INPUT CLUTCH SOLENOID VALVE
FUNCTION .............................................................. 142
Description ............................................................ 142
CONSULT-II Reference Value ............................... 142
On Board Diagnosis Logic .................................... 142
Possible Cause ..................................................... 142

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Revision: October 20052005 QX56 DTC Confirmation Procedure ............................... 142
Diagnostic Procedure ........................................... 143
DTC P1757 FRONT BRAKE SOLENOID VALVE .. 144
Description ........................................................... 144
CONSULT-II Reference Value .............................. 144
On Board Diagnosis Logic ................................... 144
Possible Cause .................................................... 144
DTC Confirmation Procedure ............................... 144
Diagnostic Procedure ........................................... 145
DTC P1759 FRONT BRAKE SOLENOID VALVE
FUNCTION .............................................................. 146
Description ........................................................... 146
CONSULT-II Reference Value .............................. 146
On Board Diagnosis Logic ................................... 146
Possible Cause .................................................... 146
DTC Confirmation Procedure ............................... 146
Diagnostic Procedure ........................................... 147
DTC P1762 DIRECT CLUTCH SOLENOID VALVE . 148
Description ........................................................... 148
CONSULT-II Reference Value .............................. 148
On Board Diagnosis Logic ................................... 148
Possible Cause .................................................... 148
DTC Confirmation Procedure ............................... 148
Diagnostic Procedure ........................................... 149
DTC P1764 DIRECT CLUTCH SOLENOID VALVE
FUNCTION .............................................................. 150
Description ........................................................... 150
CONSULT-II Reference Value .............................. 150
On Board Diagnosis Logic ................................... 150
Possible Cause .................................................... 150
DTC Confirmation Procedure ............................... 150
Diagnostic Procedure ........................................... 151
DTC P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE ................................................. 152
Description ........................................................... 152
CONSULT-II Reference Value .............................. 152
On Board Diagnosis Logic ................................... 152
Possible Cause .................................................... 152
DTC Confirmation Procedure ............................... 152
Diagnostic Procedure ........................................... 153
DTC P1769 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE FUNCTION ............................. 154
Description ........................................................... 154
CONSULT-II Reference Value .............................. 154
On Board Diagnosis Logic ................................... 154
Possible Cause .................................................... 154
DTC Confirmation Procedure ............................... 154
Diagnostic Procedure ........................................... 155
DTC P1772 LOW COAST BRAKE SOLENOID
VALVE ..................................................................... 156
Description ........................................................... 156
CONSULT-II Reference Value .............................. 156
On Board Diagnosis Logic ................................... 156
Possible Cause .................................................... 156
DTC Confirmation Procedure ............................... 156
Diagnostic Procedure ........................................... 157
DTC P1774 LOW COAST BRAKE SOLENOID
VALVE FUNCTION ................................................. 158
Description ........................................................... 158CONSULT-II Reference Value ..............................158
On Board Diagnosis Logic ....................................158
Possible Cause .....................................................158
DTC Confirmation Procedure ...............................158
Diagnostic Procedure ...........................................159
DTC P1841 ATF PRESSURE SWITCH 1 ...............160
Description ............................................................160
CONSULT-II Reference Value ..............................160
On Board Diagnosis Logic ....................................160
Possible Cause .....................................................160
DTC Confirmation Procedure ...............................160
Diagnostic Procedure ...........................................161
DTC P1843 ATF PRESSURE SWITCH 3 ...............162
Description ............................................................162
CONSULT-II Reference Value ..............................162
On Board Diagnosis Logic ....................................162
Possible Cause .....................................................162
DTC Confirmation Procedure ...............................162
Diagnostic Procedure ...........................................163
DTC P1845 ATF PRESSURE SWITCH 5 ...............164
Description ............................................................164
CONSULT-II Reference Value ..............................164
On Board Diagnosis Logic ....................................164
Possible Cause .....................................................164
DTC Confirmation Procedure ...............................164
Diagnostic Procedure ...........................................165
DTC P1846 ATF PRESSURE SWITCH 6 ...............166
Description ............................................................166
CONSULT-II Reference Value ..............................166
On Board Diagnosis Logic ....................................166
Possible Cause .....................................................166
DTC Confirmation Procedure ...............................166
Diagnostic Procedure ...........................................167
MAIN POWER SUPPLY AND GROUND CIRCUIT .168
Wiring Diagram — AT — MAIN ............................168
Diagnostic Procedure ...........................................169
CLOSED THROTTLE POSITION AND WIDE OPEN
THROTTLE POSITION CIRCUIT ............................172
CONSULT-II Reference Value ..............................172
Diagnostic Procedure ...........................................172
BRAKE SIGNAL CIRCUIT ......................................173
CONSULT-II Reference Value ..............................173
Diagnostic Procedure ...........................................173
TOW MODE SWITCH .............................................174
Description ............................................................174
Wiring Diagram — AT — TMSW ..........................175
Diagnostic Procedure ...........................................176
TROUBLE DIAGNOSIS FOR SYMPTOMS ............177
Wiring Diagram — AT — NONDTC ......................177
A/T CHECK Indicator Lamp Does Not Come On . 180
Engine Cannot Be Started In “P” or “N” Position ..180
In “P” Position, Vehicle Moves When Pushed ......181
In “N” Position, Vehicle Moves ..............................182
Large Shock (“N” to “D” Position) .........................183
Vehicle Does Not Creep Backward In “R” Position .187
Vehicle Does Not Creep Forward In “D” Position . 190
Vehicle Cannot Be Started From D
1 .....................192
A/T Does Not Shift: D
1 → D2 ................................195
A/T Does Not Shift: D
2 → D3 ................................197

AT-4Revision: October 20052005 QX56 A/T Does Not Shift: D
3 → D4 ................................199
A/T Does Not Shift: D
4 → D5 ................................202
A/T Does Not Perform Lock-up ............................204
A/T Does Not Hold Lock-up Condition ..................206
Lock-up Is Not Released ......................................208
Engine Speed Does Not Return to Idle ................209
A/T Does Not Shift: 5th gear → 4th gear ..............210
A/T Does Not Shift: 4th gear → 3rd gear ..............213
A/T Does Not Shift: 3rd gear → 2nd gear .............214
A/T Does Not Shift: 2nd gear → 1st gear .............216
Vehicle Does Not Decelerate By Engine Brake ....219
A/T SHIFT LOCK SYSTEM .....................................222
Description ............................................................222
Shift Lock System Electrical Parts Location .........222
Wiring Diagram — A/T — SHIFT ..........................223
Shift Lock Control Unit Reference Values .............224
Component Inspection ..........................................225
SHIFT CONTROL SYSTEM ....................................227
Control Device Removal and Installation ..............227
Adjustment of A/T Position ...................................228
Checking of A/T Position ......................................228
ON-VEHICLE SERVICE ..........................................229
Oil Pan ..................................................................229
Control Valve With TCM and A/T Fluid Temperature
Sensor 2 ...............................................................231
Rear Oil Seal ........................................................241
AIR BREATHER HOSE ...........................................242
Removal and Installation ......................................242
TRANSMISSION ASSEMBLY ................................244
Removal and Installation (4x2) .............................244
Removal and Installation (4x4) .............................247
OVERHAUL .............................................................250Components .......................................................... 250
Oil Channel ........................................................... 258
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings .......................... 260
DISASSEMBLY ....................................................... 262
Disassembly .......................................................... 262
REPAIR FOR COMPONENT PARTS ...................... 280
Oil Pump ............................................................... 280
Front Sun Gear, 3rd One-Way Clutch ................... 282
Front Carrier, Input Clutch, Rear Internal Gear ..... 284
Mid Sun Gear, Rear Sun Gear, High and Low
Reverse Clutch Hub .............................................. 289
High and Low Reverse Clutch .............................. 294
Direct Clutch ......................................................... 296
ASSEMBLY ............................................................. 298
Assembly (1) ......................................................... 298
Adjustment ............................................................311
Assembly (2) ......................................................... 314
SERVICE DATA AND SPECIFICATIONS (SDS) .... 321
General Specifications .......................................... 321
Vehicle Speed When Shifting Gears ..................... 321
Vehicle Speed When Performing and Releasing
Complete Lock-up ................................................. 322
Vehicle Speed When Performing and Releasing
Slip Lock-up .......................................................... 322
Stall Speed ............................................................ 322
Line Pressure ........................................................ 322
A/T Fluid Temperature Sensor .............................. 322
Turbine Revolution Sensor .................................... 322
Vehicle Speed Sensor A/T (Revolution Sensor) ... 322
Reverse brake ....................................................... 323
Total End Play ....................................................... 323

PRECAUTIONS
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Service Notice or PrecautionsECS00CDM
ATF COOLER SERVICE
If A/T fluid contains frictional material (clutches, bands, etc.), or if an A/T is repaired, overhauled, or replaced,
inspect and clean the A/T fluid cooler mounted in the radiator or replace the radiator. Flush cooler lines using
cleaning solvent and compressed air after repair. For A/T fluid cooler cleaning procedure, refer to AT-13, "
A/T
Fluid Cooler Cleaning" . For radiator replacement, refer to CO-12, "Removal and Installation" .
CHECKING AND CHANGING A/T FLUID SERVICE
Increase ATF temperature by 80°C (176°F) once, and then check ATF level in 65°C (149°F) when adjusting
ATF level.
NOTE:
JA60 uses both systems of a water-cooling and of an air-cooling. Air-cooling system has a by-pass valve.
When ATF temperature is not over 50°C (122°F) with water-cooling system OFF, it does not flow to air-cooling
system. If ATF level is set without the flow of ATF, the level will be 10mm lower than the standard. Therefore,
piping should be filled with ATF when adjusting level.
OBD-II SELF-DIAGNOSIS

A/T self-diagnosis is performed by the TCM in combination with the ECM. Refer to the table on AT-85,
"SELF-DIAGNOSTIC RESULT MODE" for the indicator used to display each self-diagnostic result.

The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM mem-
ories.
Always perform the procedure on AT-3 8, "
HOW TO ERASE DTC" to complete the repair and avoid
unnecessary blinking of the MIL.
For details of OBD-II, refer to EC-48, "
ON BOARD DIAGNOSTIC (OBD) SYSTEM" .

Certain systems and components, especially those related to OBD, may use the new style slide-
locking type harness connector. For description and how to disconnect, refer to PG-67, "
HAR-
NESS CONNECTOR" .
Wiring Diagrams and Trouble DiagnosisECS0 0CD N
When you read wiring diagrams, refer to the following:

GI-15, "How to Read Wiring Diagrams".

PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit.
When you perform trouble diagnosis, refer to the following:

GI-11, "How to Follow Trouble Diagnoses".

GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident".

A/T CONTROL SYSTEM
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TCM FunctionECS00CDW
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
SENSORS (or SIGNALS)


TCM


ACTUATORS
PNP switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Stop lamp switch signal
Turbine revolution sensor
1st position switch signal
4th position switch signal
ATF pressure switch signal
Tow mode switch signalShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Sta rte r re lay
Back-up lamp relay
SCIA5624E

A/T CONTROL SYSTEM
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Shift Change System Diagram
*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlECS00CE1
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released

In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
PCIA0013E
Select lever D position 4 position 3 position 2 position
Gear position 5 4 4 3 2
Lock-up×–×××
Slip lock-up××–––
PCIA0014E

TROUBLE DIAGNOSIS
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Circuit DiagramECS00CED
BCWA0409E