2006 INFINITI QX56 wiring

AT-1
AUTOMATIC TRANSMISSION
C TRANSMISSION/TRANSAXLE
CONTENTS
DE
F
G H
I
J
K L
M
SECTION
A
B
AT
Revision: November 2009 2006 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
PREPARATION ...................................................... ... 10
Special Service Tools .......................................... ... 10
Commercial Service Tools ................................... .... 11
A/T FLUID .............................................................. ... 12
Changing Automatic Transmission Fluid (ATF) ... ... 12
Checking Automatic Transmission Fluid (ATF) ... ... 12
A/T Fluid Cooler Cleaning ................................... ... 14
A/T CONTROL SYSTEM ....................................... ... 17
Cross-Sectional View (2WD models) .................. ... 17
Cross-Sectional View (4WD models) .................. ... 18
Shift Mechanism .................................................. ... 19
TCM Function ...................................................... ... 30
CAN Communication ........................................... ... 31
Input/Output Signal of TCM ................................. ... 31
Line Pressure Control ......................................... ... 32
Shift Control ........................................................ ... 33
Lock-up Control ................................................... ... 34
Engine Brake Control .......................................... ... 36
Control Valve ....................................................... ... 36
ON BOARD DIAGNOSTIC (OBD) SYSTEM ......... ... 38
Introduction ......................................................... ... 38
OBD-II Function for A/T System .......................... ... 38
One or Two Trip Detection Logic of OBD-II ......... ... 38
OBD-II Diagnostic Trouble Code (DTC) .............. ... 38
Malfunction Indicator Lamp (MIL) ........................ ... 41
TROUBLE DIAGNOSIS ......................................... ... 42
DTC Inspection Priority Chart ............................. ... 42
Fail-Safe .............................................................. ... 42
How To Perform Trouble Diagnosis For Quick and Accurate Repair ...................................................
... 44
A/T Electrical Parts Location ............................... ... 49
Circuit Diagram ....................................................... 50
Inspections Before Trouble Diagnosis ................. ... 51
Check Before Engine is Started ........................... ... 55
Check at Idle ........................................................... 55
Cruise Test - Part 1 .............................................. ... 56
Cruise Test - Part 2 .............................................. ... 58
Cruise Test - Part 3 .............................................. ... 59
Vehicle Speed When Shifting Gears ................... ... 60
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................. 60
Vehicle Speed When Performing and Releasing
Slip Lock-up ............................................................ 60
Symptom Chart ....................................................... 61
TCM Input/Output Signal Reference Values ........ ... 83
CONSULT-II Function (A/T) ................................. ... 84
DTC U1000 CAN COMMUNICATION LINE ........... ... 96
Description ........................................................... ... 96
On Board Diagnosis Logic ................................... ... 96
Possible Cause ....................................................... 96
DTC Confirmation Procedure .............................. ... 96
Wiring Diagram — AT — CAN ............................. ... 97
Diagnostic Procedure .......................................... ... 99
DTC P0615 START SIGNAL CIRCUIT .................. .100
Description ........................................................... .100
CONSULT-II Reference Value ............................. .100
On Board Diagnosis Logic ................................... .100
Possible Cause .................................................... .100
DTC Confirmation Procedure .............................. .100
Wiring Diagram — AT — STSIG ......................... .101
Diagnostic Procedure .......................................... .102
DTC P0700 TCM .................................................... .104
Description ........................................................... .104
On Board Diagnosis Logic ................................... .104
Possible Cause .................................................... .104
DTC Confirmation Procedure .............................. .104
Diagnostic Procedure .......................................... .104
DTC P0705 PARK/NEUTRAL POSITION SWITCH .105
Description ........................................................... .105

AT-2Revision: November 20092006 QX56
CONSULT-II Reference Value .............................
.105
On Board Diagnosis Logic ................................... .105
Possible Cause .................................................... .105
DTC Confirmation Procedure .............................. .105
Wiring Diagram — AT — PNP/SW ...................... .106
Diagnostic Procedure .......................................... .107
DTC P0717 TURBINE REVOLUTION SENSOR ... .109
Description ........................................................... .109
CONSULT-II Reference Value ............................. .109
On Board Diagnosis Logic ................................... .109
Possible Cause .................................................... .109
DTC Confirmation Procedure .............................. .109
Diagnostic Procedure .......................................... .110
DTC P0720 VEHICLE SPEED SENSOR A/T (REV-
OLUTION SENSOR) .............................................. . 111
Description ........................................................... ..111
CONSULT-II Reference Value ...............................111
On Board Diagnosis Logic ................................... ..111
Possible Cause ......................................................111
DTC Confirmation Procedure .............................. ..111
Wiring Diagram — AT — VSSA/T ........................ .113
Diagnostic Procedure .......................................... .114
DTC P0725 ENGINE SPEED SIGNAL .................. .116
Description ........................................................... .116
CONSULT-II Reference Value ............................. .116
On Board Diagnosis Logic ................................... .116
Possible Cause .................................................... .116
DTC Confirmation Procedure .............................. .116
Diagnostic Procedure .......................................... .116
DTC P0740 TORQUE CONVERTER CLUTCH
SOLENOID VALVE ................................................ .118
Description ........................................................... .118
CONSULT-II Reference Value ............................. .118
On Board Diagnosis Logic ................................... .118
Possible Cause .................................................... .118
DTC Confirmation Procedure .............................. .118
Diagnostic Procedure .......................................... .119
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP) .120
Description ........................................................... .120
CONSULT-II Reference Value ............................. .120
On Board Diagnosis Logic ................................... .120
Possible Cause .................................................... .120
DTC Confirmation Procedure .............................. .120
Diagnostic Procedure .......................................... .121
DTC P0745 LINE PRESSURE SOLENOID VALVE .122
Description ........................................................... .122
CONSULT-II Reference Value ............................. .122
On Board Diagnosis Logic ................................... .122
Possible Cause .................................................... .122
DTC Confirmation Procedure .............................. .122
Diagnostic Procedure .......................................... .123
DTC P1705 THROTTLE POSITION SENSOR ...... .124
Description ........................................................... .124
CONSULT-II Reference Value ............................. .124
On Board Diagnosis Logic ................................... .124
Possible Cause .................................................... .124
DTC Confirmation Procedure .............................. .124
Diagnostic Procedure .......................................... .124
DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT .................................................................
.127
Description ........................................................... .127
CONSULT-II Reference Value .............................. .127
On Board Diagnosis Logic ................................... .127
Possible Cause .................................................... .127
DTC Confirmation Procedure ............................... .127
Wiring Diagram — AT — FTS .............................. .128
Diagnostic Procedure ........................................... .129
Component Inspection ......................................... .130
DTC P1721 VEHICLE SPEED SENSOR MTR ...... .132
Description ........................................................... .132
CONSULT-II Reference Value .............................. .132
On Board Diagnosis Logic ................................... .132
Possible Cause .................................................... .132
DTC Confirmation Procedure ............................... .132
Diagnostic Procedure ........................................... .133
DTC P1730 A/T INTERLOCK ................................ .134
Description ........................................................... .134
On Board Diagnosis Logic ................................... .134
Possible Cause .................................................... .134
DTC Confirmation Procedure ............................... .134
Judgement of A/T Interlock .................................. .135
Diagnostic Procedure ........................................... .135
DTC P1731 A/T 1ST ENGINE BRAKING .............. .137
Description ........................................................... .137
CONSULT-II Reference Value .............................. .137
On Board Diagnosis Logic ................................... .137
Possible Cause .................................................... .137
DTC Confirmation Procedure ............................... .137
Diagnostic Procedure ........................................... .138
DTC P1752 INPUT CLUTCH SOLENOID VALVE . .139
Description ........................................................... .139
CONSULT-II Reference Value .............................. .139
On Board Diagnosis Logic ................................... .139
Possible Cause .................................................... .139
DTC Confirmation Procedure ............................... .139
Diagnostic Procedure ........................................... .140
DTC P1754 INPUT CLUTCH SOLENOID VALVE
FUNCTION ............................................................. .141
Description ........................................................... .141
CONSULT-II Reference Value .............................. .141
On Board Diagnosis Logic ................................... .141
Possible Cause .................................................... .141
DTC Confirmation Procedure ............................... .141
Diagnostic Procedure ........................................... .142
DTC P1757 FRONT BRAKE SOLENOID VALVE .. .143
Description ........................................................... .143
CONSULT-II Reference Value .............................. .143
On Board Diagnosis Logic ................................... .143
Possible Cause .................................................... .143
DTC Confirmation Procedure ............................... .143
Diagnostic Procedure ........................................... .144
DTC P1759 FRONT BRAKE SOLENOID VALVE
FUNCTION ............................................................. .145
Description ........................................................... .145
CONSULT-II Reference Value .............................. .145
On Board Diagnosis Logic ................................... .145
Possible Cause .................................................... .145

AT-3
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
DTC Confirmation Procedure ..............................
. 145
Diagnostic Procedure .......................................... . 146
DTC P1762 DIRECT CLUTCH SOLENOID VALVE . 147
Description .......................................................... . 147
CONSULT-II Reference Value ............................. . 147
On Board Diagnosis Logic .................................. . 147
Possible Cause ................................................... . 147
DTC Confirmation Procedure .............................. . 147
Diagnostic Procedure .......................................... . 148
DTC P1764 DIRECT CLUTCH SOLENOID VALVE
FUNCTION ............................................................. . 149
Description .......................................................... . 149
CONSULT-II Reference Value ............................. . 149
On Board Diagnosis Logic .................................. . 149
Possible Cause ................................................... . 149
DTC Confirmation Procedure .............................. . 149
Diagnostic Procedure .......................................... . 150
DTC P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE ................................................ . 151
Description .......................................................... . 151
CONSULT-II Reference Value ............................. . 151
On Board Diagnosis Logic .................................. . 151
Possible Cause ................................................... . 151
DTC Confirmation Procedure .............................. . 151
Diagnostic Procedure .......................................... . 152
DTC P1769 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE FUNCTION ............................ . 153
Description .......................................................... . 153
CONSULT-II Reference Value ............................. . 153
On Board Diagnosis Logic .................................. . 153
Possible Cause ................................................... . 153
DTC Confirmation Procedure .............................. . 153
Diagnostic Procedure .......................................... . 154
DTC P1772 LOW COAST BRAKE SOLENOID
VALVE .................................................................... . 155
Description .......................................................... . 155
CONSULT-II Reference Value ............................. . 155
On Board Diagnosis Logic .................................. . 155
Possible Cause ................................................... . 155
DTC Confirmation Procedure .............................. . 155
Diagnostic Procedure .......................................... . 156
DTC P1774 LOW COAST BRAKE SOLENOID
VALVE FUNCTION ................................................ . 157
Description .......................................................... . 157
CONSULT-II Reference Value ............................. . 157
On Board Diagnosis Logic .................................. . 157
Possible Cause ................................................... . 157
DTC Confirmation Procedure .............................. . 157
Diagnostic Procedure .......................................... . 158
DTC P1841 ATF PRESSURE SWITCH 1 .............. . 159
Description .......................................................... . 159
CONSULT-II Reference Value ............................. . 159
On Board Diagnosis Logic .................................. . 159
Possible Cause ................................................... . 159
DTC Confirmation Procedure .............................. . 159
Diagnostic Procedure .......................................... . 160
DTC P1843 ATF PRESSURE SWITCH 3 .............. . 161
Description .......................................................... . 161
CONSULT-II Reference Value ............................. . 161On Board Diagnosis Logic ...................................
.161
Possible Cause .................................................... .161
DTC Confirmation Procedure .............................. .161
Diagnostic Procedure .......................................... .162
DTC P1845 ATF PRESSURE SWITCH 5 .............. .163
Description ........................................................... .163
CONSULT-II Reference Value ............................. .163
On Board Diagnosis Logic ................................... .163
Possible Cause .................................................... .163
DTC Confirmation Procedure .............................. .163
Diagnostic Procedure .......................................... .164
DTC P1846 ATF PRESSURE SWITCH 6 .............. .165
Description ........................................................... .165
CONSULT-II Reference Value ............................. .165
On Board Diagnosis Logic ................................... .165
Possible Cause .................................................... .165
DTC Confirmation Procedure .............................. .165
Diagnostic Procedure .......................................... .166
MAIN POWER SUPPLY AND GROUND CIRCUIT .167
Wiring Diagram — AT — MAIN ........................... .167
Diagnostic Procedure .......................................... .168
CLOSED THROTTLE POSITION AND WIDE OPEN
THROTTLE POSITION CIRCUIT ........................... .171
CONSULT-II Reference Value ............................. .171
Diagnostic Procedure .......................................... .171
BRAKE SIGNAL CIRCUIT ..................................... .172
CONSULT-II Reference Value ............................. .172
Diagnostic Procedure .......................................... .172
TOW MODE SWITCH ............................................ .173
Description ........................................................... .173
Wiring Diagram — AT — TMSW ......................... .174
Diagnostic Procedure .......................................... .175
TROUBLE DIAGNOSIS FOR SYMPTOMS ........... .176
Wiring Diagram — AT — NONDTC ..................... .176
A/T CHECK Indicator Lamp Does Not Come On . 179
Engine Cannot Be Started In “P” or “N” Position . .179
In “P” Position, Vehicle Moves When Pushed ..... .180
In “N” Position, Vehicle Moves ............................. .181
Large Shock (“N” to “D” Position) ........................ .182
Vehicle Does Not Creep Backward In “R” Position .186
Vehicle Does Not Creep Forward In “D” Position . 189
Vehicle Cannot Be Started From D
1 .................... .191
A/T Does Not Shift: D
1 → D2 ............................... .194
A/T Does Not Shift: D
2 → D3 ............................... .196
A/T Does Not Shift: D
3 → D4 ............................... .198
A/T Does Not Shift: D
4 → D5 ............................... .201
A/T Does Not Perform Lock-up ........................... .203
A/T Does Not Hold Lock-up Condition ................. .205
Lock-up Is Not Released ..................................... .207
Engine Speed Does Not Return to Idle ............... .208
A/T Does Not Shift: 5th gear → 4th gear ............. .209
A/T Does Not Shift: 4th gear → 3rd gear ............. .212
A/T Does Not Shift: 3rd gear → 2nd gear ............ .213
A/T Does Not Shift: 2nd gear → 1st gear .............215
Vehicle Does Not Decelerate By Engine Brake ... .218
A/T SHIFT LOCK SYSTEM ................................... .221
Description ........................................................... .221
Shift Lock System Electrical Parts Location ........ .221
Wiring Diagram — A/T — SHIFT ......................... .222

PRECAUTIONSAT-7
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
ECS00CDJ
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER ”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:

To 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 per-
formed by an authorized NISSAN/INFINITI dealer.

Improper 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 SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for On Board Diagnostic (OBD) System of A/T and EngineECS00CDK
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:

Be sure to turn the ignition switch “OFF” and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. Will cause the MIL to light up.

Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)

Be sure to route and secure the harnesses properly after work. Interference of the harness with a
bracket, etc. May cause the MIL to light up due to a short circuit.

Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system, etc.

Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.

A/T CONTROL SYSTEMAT-31
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
CAN CommunicationECS00CDX
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-26,
"CAN COMMUNICATION" .
Input/Output Signal of TCMECS00CDY
*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: CAN communications Control item
Line
pressure
control Vehicle
speed
control Shift
control Lock-up
control Engine
brake
control Fail-safe
function
(*3) Self-diag-
nostics
function
Input Accelerator pedal position signal
(*4)XXXXXXX
Vehicle speed sensor A/T
(revolution sensor) XXXX
XX
Vehicle speed sensor MTR
(*1) (*4)XXXX X
Closed throttle position signal
(*4)(*2) X (*2) X X (*2) XX
Wide open throttle position signal
(*4)(*2) X (*2) X (*2) XX
Turbine revolution sensor 1 XX X XX
Turbine revolution sensor 2
(for 4th speed only) XX
XXX
Engine speed signals
(*4)XX
PNP s witch XXXXXXX
A/T fluid temp eratu re senso rs 1, 2XXXXXXX
ASCD Operation signal
(*4)XXXX
Overdrive cancel
signal
(*4)XX X
TCM power supply voltage signal XXXXX X
Out-
put Direct clutch solenoid (ATF pres-
sure switch 5)
XX
XX
Input clutch solenoid (ATF pressure
switch 3) XX
XX
High and low reverse clutch sole-
noid (ATF pressure switch 6) XX
XX
Front brake solenoid (ATF pressure
switch 1) XX
XX
Low coast brake solenoid (ATF
pressure switch 2) XX
XXX
L in e p re ssu re s olen oid XXXXXXX
TCC solenoid XX X
Sta rter rela y XX

AT-44
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
How To Perform Trouble Diagnosis For Quick and Accurate RepairECS00CEB
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelerator pedal position sensor (throttle position
sensor) or PNP switch and provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
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 oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the AT- 4 5 , "
WORK FLOW" .
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 errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” as shown on
the example (Refer to AT- 4 6
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
SAT631IB
SAT632I
SEF234G

AT-96
DTC U1000 CAN COMMUNICATION LINE
Revision: November 20092006 QX56
DTC U1000 CAN COMMUNICATION LINEPFP:23710
DescriptionECS00CEQ
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 malfunction detection ability.
Many electronic 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 con-
nected 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.
On Board Diagnosis LogicECS00CER

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “U1000 CAN COMM CIRCUIT ” with CONSULT-II is detected when TCM cannot
communicate to other control units.
Possible CauseECS00CES
Harness or connectors
(CAN communication line is open or shorted.)
DTC Confirmation ProcedureECS00CET
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch “ ON”. (Do not start engine.)
2. Select “DATA MONITOR ” mode for “ENGINE ” with CONSULT-II.
3. Start engine and wait for at least 6 seconds.
4. If DTC is detected, go to AT- 9 9 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
BCIA0030E

DTC U1000 CAN COMMUNICATION LINEAT-97
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
Wiring Diagram — AT — CANECS00CEU
BCWA0320E