2007 INFINITI QX56 service

AT-1
TRANSMISSION/TRANSAXLE
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SECTION AT
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CONTENTS
AUTOMATIC TRANSMISSION
SERVICE INFORMATION ............................6
INDEX FOR DTC .................................................6
Alphabetical Index .....................................................6
DTC No. Index ..........................................................6
PRECAUTIONS ...................................................8
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
8
Precaution for On Board Diagnosis (OBD) System
of A/T and Engine .....................................................
8
Precaution .................................................................8
Service Notice or Precaution .....................................9
PREPARATION ..................................................11
Special Service Tool ...............................................11
Commercial Service Tool ........................................12
A/T FLUID ...........................................................13
Changing Automatic Transmission Fluid (ATF) ......13
Checking Automatic Transmission Fluid (ATF) .......13
A/T Fluid Cooler Cleaning .......................................15
A/T CONTROL SYSTEM ....................................19
Cross-Sectional View (2WD models) ......................19
Cross-Sectional View (4WD models) ......................20
Shift Mechanism ......................................................20
TCM Function ..........................................................31
CAN Communication ...............................................32
Input/Output Signal of TCM .....................................33
Line Pressure Control .............................................33
Shift Control ............................................................35
Lock-up Control .......................................................36
Engine Brake Control ..............................................37
Control Valve ...........................................................37
ON BOARD DIAGNOSTIC (OBD) SYSTEM ......39
Introduction .............................................................39
OBD-II Function for A/T System ..............................39
One or Two Trip Detection Logic of OBD-II ............39
OBD-II Diagnostic Trouble Code (DTC) ..................39
Malfunction Indicator Lamp (MIL) ............................41
TROUBLE DIAGNOSIS ....................................43
DTC Inspection Priority Chart ..................................43
Fail-Safe ..................................................................43
How To Perform Trouble Diagnosis for Quick and
Accurate Repair .......................................................
44
A/T Electrical Parts Location ...................................50
Circuit Diagram ........................................................51
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 .......................59
Vehicle Speed When Performing and Releasing
Complete Lock-up ...................................................
60
Vehicle Speed When Performing and Releasing
Slip Lock-up .............................................................
60
Symptom Chart ........................................................60
TCM Input/Output Signal Reference Value .............82
CONSULT-II Function (A/T) ....................................83
DTC U1000 CAN COMMUNICATION LINE .....91
Description ...............................................................91
On Board Diagnosis Logic .......................................91
Possible Cause ........................................................91
DTC Confirmation Procedure ..................................91
Wiring Diagram - AT - CAN .....................................92
Diagnosis Procedure ...............................................93
DTC P0615 START SIGNAL CIRCUIT .............94
Description ...............................................................94
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................
94
On Board Diagnosis Logic .......................................94
Possible Cause ........................................................94
DTC Confirmation Procedure ..................................94
Wiring Diagram - AT - STSIG ..................................95
Diagnosis Procedure ...............................................95

AT-4
DTC Confirmation Procedure ................................152
Diagnosis Procedure .............................................152
DTC P1845 ATF PRESSURE SWITCH 5 ........154
Description .............................................................154
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
154
On Board Diagnosis Logic .....................................154
Possible Cause ......................................................154
DTC Confirmation Procedure ................................154
Diagnosis Procedure .............................................154
DTC P1846 ATF PRESSURE SWITCH 6 ........156
Description .............................................................156
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
156
On Board Diagnosis Logic .....................................156
Possible Cause ......................................................156
DTC Confirmation Procedure ................................156
Diagnosis Procedure .............................................156
MAIN POWER SUPPLY AND GROUND CIR-
CUIT .................................................................
158
Wiring Diagram - AT - MAIN ..................................158
Diagnosis Procedure .............................................159
CLOSED THROTTLE POSITION AND WIDE
OPEN THROTTLE POSITION CIRCUIT .........
161
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
161
Diagnosis Procedure .............................................161
BRAKE SIGNAL CIRCUIT ..............................162
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
162
Diagnosis Procedure .............................................162
TOW MODE SWITCH ......................................163
Description .............................................................163
Wiring Diagram - AT - TMSW ................................163
Diagnosis Procedure .............................................164
TROUBLE DIAGNOSIS FOR SYMPTOMS .....165
Wiring Diagram - AT - NONDTC ............................165
A/T Check Indicator Lamp Does Not Come On .....167
Engine Cannot Be Started in "P" or "N" Position ...168
In "P" Position, Vehicle Moves When Pushed .......168
In "N" Position, Vehicle Moves ..............................169
Large Shock ("N" to "D" Position) ..........................170
Vehicle Does Not Creep Backward in "R" Position ..172
Vehicle Does Not Creep Forward in "D" Position ..175
Vehicle Cannot Be Started from D1 .......................177
A/T Does Not Shift: D1→ D2 ..................................179
A/T Does Not Shift: D2→ D3 ..................................181
A/T Does Not Shift: D3→ D4 ..................................183
A/T Does Not Shift: D4→ D5 ..................................185
A/T Does Not Perform Lock-up .............................187
A/T Does Not Hold Lock-up Condition ...................189
Lock-up Is Not Released .......................................190
Engine Speed Does Not Return to Idle .................191
A/T Does Not Shift: 5th gear → 4th gear ..............192
A/T Does Not Shift: 4th gear → 3rd gear ..............194
A/T Does Not Shift: 3rd gear → 2nd gear .............196
A/T Does Not Shift: 2nd gear → 1st gear .............197
Vehicle Does Not Decelerate By Engine Brake ....199
A/T SHIFT LOCK SYSTEM ..............................202
Description ............................................................202
Shift Lock System Electrical Parts Location ..........202
Wiring Diagram - AT - SHIFT ................................203
Shift Lock Control Unit Reference Value ..............204
Component Inspection ..........................................204
SHIFT CONTROL SYSTEM .............................207
Control Device Removal and Installation ..............207
Adjustment of A/T Position ....................................208
Checking of A/T Position .......................................208
ON-VEHICLE SERVICE ...................................209
Oil Pan ..................................................................209
Control Valve with TCM and A/T Fluid Tempera-
ture Sensor 2 ........................................................
210
Rear Oil Seal .........................................................219
AIR BREATHER HOSE ....................................221
Removal and Installation .......................................221
TRANSMISSION ASSEMBLY ..........................223
Removal and Installation (2WD) ...........................223
Removal and Installation (4WD) ...........................225
OVERHAUL ......................................................228
Component ...........................................................228
Oil Channel ...........................................................235
Location of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................
237
DISASSEMBLY ................................................240
Disassembly ..........................................................240
REPAIR FOR COMPONENT PARTS ..............258
Oil Pump ...............................................................258
Front Sun Gear, 3rd One-Way Clutch ...................260
Front Carrier, Input Clutch, Rear Internal Gear .....262
Mid Sun Gear, Rear Sun Gear, High and Low Re-
verse Clutch Hub ..................................................
267
High and Low Reverse Clutch ..............................272
Direct Clutch .........................................................274
ASSEMBLY ......................................................277
Assembly (1) .........................................................277
Adjustment ............................................................290
Assembly (2) .........................................................292
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
298
General Specification ............................................298
Vehicle Speed When Shifting Gears .....................298
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................
299
Stall Speed ............................................................299

AT-6
< SERVICE INFORMATION >
INDEX FOR DTC
SERVICE INFORMATION
INDEX FOR DTC
Alphabetical IndexINFOID:0000000003532216
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 9 1
.
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DTC No. IndexINFOID:0000000003532217
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 9 1
.
Items
(CONSULT- II screen terms) DTC
Reference page OBD- II Except OBD- II
CONSULT- II GST (*1) CONSULT- II only “A/T”
A/T 1ST E/BRAKING — P1731AT- 1 2 8
ATF PRES SW 1/CIRC — P1841AT- 1 5 0
ATF PRES SW 3/CIRC — P1843AT- 1 5 2
ATF PRES SW 5/CIRC — P1845AT- 1 5 4
ATF PRES SW 6/CIRC — P1846AT- 1 5 6
A/T INTERLOCK P1730 P1730AT- 1 2 6
A/T TCC S/V FNCTN P0744 P0744 AT- 11 3
ATF TEMP SEN/CIRC P0710 P1710AT- 11 9
CAN COMM CIRCUIT U1000 U1000AT- 9 1
D/C SOLENOID/CIRC P1762 P1762AT- 1 3 8
D/C SOLENOID FNCTN P1764 (*2) P1764 AT- 1 4 0
ENGINE SPEED SIG — P0725AT- 1 0 9
FR/B SOLENOID/CIRC P1757 P1757AT- 1 3 4
FR/B SOLENOID FNCT P1759 P1759 AT- 1 3 6
HLR/C SOL/CIRC P1767 P1767AT- 1 4 2
HLR/C SOL FNCTN P1769 (*2) P1769 AT- 1 4 4
I/C SOLENOID/CIRC P1752 P1752AT- 1 3 0
I/C SOLENOID FNCTN P1754 (*2) P1754 AT- 1 3 2
L/PRESS SOL/CIRC P0745 P0745AT- 11 5
LC/B SOLENOID/CIRC P1772 P1772AT- 1 4 6
LC/B SOLENOID FNCT P1774 P1774 AT- 1 4 8
PNP SW/CIRC P0705 P0705AT- 9 9
STARTER RELAY/CIRC — P0615AT- 9 4
TCC SOLENOID/CIRC P0740 P0740AT- 111
TCM P0700 P0700AT- 9 8
TP SEN/CIRC A/T — P1705AT- 11 7
TURBINE REV S/CIRC P0717 P0717AT- 1 0 3
VEH SPD SE/CIR·MTR — P1721AT- 1 2 4
VEH SPD SEN/CIR AT P0720 P0720AT- 1 0 5

INDEX FOR DTC
AT-7
< SERVICE INFORMATION >
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*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.DTC
Items
(CONSULT- II screen terms)Reference page OBD- II Except OBD- II
CONSULT- II
GST (*1)C O N S U LT- I I
only “A/T”
— P0615 STARTER RELAY/CIRCAT- 9 4
P0700 P0700 TCMAT- 9 8
P0705 P0705 PNP SW/CIRCAT- 9 9
P0710 P1710 ATF TEMP SEN/CIRCAT- 11 9
P0717 P0717 TURBINE REV S/CIRCAT- 1 0 3
P0720 P0720 VEH SPD SEN/CIR ATAT- 1 0 5
— P0725 ENGINE SPEED SIGAT- 1 0 9
P0740 P0740 TCC SOLENOID/CIRCAT- 111
P0744 P0744 A/T TCC S/V FNCTNAT- 11 3
P0745 P0745 L/PRESS SOL/CIRCAT- 11 5
— P1705 TP SEN/CIRC A/TAT- 11 7
— P1721 VEH SPD SE/CIR·MTRAT- 1 2 4
P1730 P1730 A/T INTERLOCKAT- 1 2 6
— P1731 A/T 1ST E/BRAKINGAT- 1 2 8
P1752 P1752 I/C SOLENOID/CIRCAT- 1 3 0
P1754 (*2) P1754 I/C SOLENOID FNCTNAT- 1 3 2
P1757 P1757 FR/B SOLENOID/CIRCAT- 1 3 4
P1759 (*2) P1759 FR/B SOLENOID FNCTAT- 1 3 6
P1762 P1762 D/C SOLENOID/CIRCAT- 1 3 8
P1764 (*2) P1764 D/C SOLENOID FNCTNAT- 1 4 0
P1767 P1767 HLR/C SOL/CIRCAT- 1 4 2
P1769 P1769 HLR/C SOL FNCTNAT- 1 4 4
P1772 P1772 LC/B SOLENOID/CIRCAT- 1 4 6
P1774 P1774 LC/B SOLENOID FNCTAT- 1 4 8
— P1841 ATF PRES SW 1/CIRCAT- 1 5 0
— P1843 ATF PRES SW 3/CIRCAT- 1 5 2
— P1845 ATF PRES SW 5/CIRCAT- 1 5 4
— P1846 ATF PRES SW 6/CIRCAT- 1 5 6
U1000 U1000 CAN COMM CIRCUITAT- 9 1

AT-8
< SERVICE INFORMATION >
PRECAUTIONS
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003532218
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 performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal
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 har-
ness connectors.
Precaution for On Board Diagnosis (OBD) System of A/T and EngineINFOID:0000000003532219
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.
PrecautionINFOID:0000000003532220
•Before connecting or disconnecting the A/T assembly har-
ness connector, turn ignition switch “OFF” and disconnect
negative battery cable. Because battery voltage is applied to
TCM even if ignition switch is turned “OFF”.
SEF289H

PRECAUTIONS
AT-9
< SERVICE INFORMATION >
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•After performing each TROUBLE DIAGNOSIS, perform “DTC
(Diagnostic Trouble Code) CONFIRMATION PROCEDURE”.
If the repair is completed the DTC should not be displayed in
the “DTC CONFIRMATION PROCEDURE”.
• Always use the specified brand of ATF. Refer to MA-10
.
• Use paper rags not cloth rags during work.
• After replacing the ATF, dispose of the waste oil using the methods prescribed by law, ordinance, etc.
• Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to pre-
vent the internal parts from becoming contaminated by dirt or other foreign matter.
• Disassembly should be done in a clean work area.
• Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the transmission.
• Place disassembled parts in order for easier and proper assembly.
• All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.
• Gaskets, seals and O-rings should be replaced any time the transmission is disassembled.
• It is very important to perform functional tests whenever they are indicated.
• The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent springs
and small parts from becoming scattered or lost.
• Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
• Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings and
seals, or hold bearings and washers in place during assembly. Do not use grease.
• Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
• Clean or replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer. Refer to AT-
15, "A/T Fluid Cooler Cleaning".
• After overhaul, refill the transmission with new ATF.
• When the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque con-
verter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer to
AT-13, "
Changing Automatic Transmission Fluid (ATF)", AT-13, "Checking Automatic Transmission Fluid
(ATF)".
Service Notice or PrecautionINFOID:0000000003532221
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-15, "
A/T
Fluid Cooler Cleaning". For radiator replacement, refer to CO-13.
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-83,
"CONSULT-II Function (A/T)" for the indicator used to display each self-diagnostic result.
SEF217U

AT-10
< SERVICE INFORMATION >
PRECAUTIONS
• The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM memo-
ries.
Always perform the procedure on AT-39, "
OBD-II Diagnostic Trouble Code (DTC)" to complete the
repair and avoid unnecessary blinking of the MIL.
For details of OBD-II, refer to EC-48
.
•Certain systems and components, especially those related to OBD, may use the new style slide-lock-
ing type harness connector. For description and how to disconnect, refer to PG-66
.

PREPARATION
AT-11
< SERVICE INFORMATION >
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PREPARATION
Special Service ToolINFOID:0000000003532222
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
ST2505S001
(J-34301-C)
Oil pressure gauge set
1. ST25051001
(—)
Oil pressure gauge
2. ST25052000
(—)
Hose
3. ST25053000
(—)
Joint pipe
4. ST25054000
(—)
Adapter
5. ST25055000
(—)
AdapterMeasuring line pressure
KV31103600
(J-45674)
Joint pipe adapter
(With ST25054000)Measuring line pressure
ST33400001
(J-26082)
Drift• Installing rear oil seal (2WD models)
• Installing oil pump housing oil seal
a: 60 mm (2.36 in) dia.
b: 47 mm (1.85 in) dia.
KV31102400
(J-34285 and J-34285-87)
Clutch spring compressorInstalling reverse brake return spring retainer
a: 320 mm (12.60 in)
b: 174 mm (6.85 in)
ZZA0600D
ZZA1227D
NT086
NT423