diagram INFINITI QX56 2008 Factory Service Manual

STR-1
ENGINE
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SECTION STR
A
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CONTENTS
STARTING SYSTEM
PRECAUTION ....... ........................................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Power Generation Variable Voltage
Control System ..........................................................
3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tool ........................................... ......4
Commercial Service Tool ..........................................4
BASIC INSPECTION ....................................5
DIAGNOSIS AND REPAIR WORKFLOW ..... .....5
Work Flow ........................................................... ......5
FUNCTION DIAGNOSIS ...............................8
STARTING SYSTEM ...................................... .....8
System Diagram .................................................. ......8
System Description ...................................................8
Component Parts Location ........................................8
Component Description ............................................9
COMPONENT DIAGNOSIS .........................10
B TERMINAL CIRCUIT .....................................10
Description ........................................................... ....10
Diagnosis Procedure ...............................................10
S CONNECTOR CIRCUIT .................................11
Description ...............................................................11
Diagnosis Procedure ...............................................11
STARTING SYSTEM .........................................12
Wiring Diagram .................................................... ....12
SYMPTOM DIAGNOSIS ..............................16
STARTING SYSTEM .........................................16
Symptom Table ................................................... ....16
ON-VEHICLE REPAIR .................................17
STARTER MOTOR ...........................................17
Removal and Installation ..................................... ....17
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
18
STARTER MOTOR ...........................................18
Starter .................................................................. ....18
Revision: March 2010 2008 QX56

STR-8
< FUNCTION DIAGNOSIS >
STARTING SYSTEM
FUNCTION DIAGNOSIS
STARTING SYSTEM
System DiagramINFOID:0000000001696224
System DescriptionINFOID:0000000001696225
The starter motor plunger closes and provides a closed circuit between the battery and the starter motor. The
starter motor is grounded to the cylinder block. With power and ground supplied, the starter motor operates.
Component Parts LocationINFOID:0000000001696226
ALBIA0416GB
1. A/T assembly F9 (with built in TCM
F502) 2. IPDM E/R E119, E120, E122, E124 3. BCM M18 (view with instrument panel
lower LH panel removed)
AWBIA0127ZZ
Revision: March 2010 2008 QX56

STR-12
< COMPONENT DIAGNOSIS >
STARTING SYSTEM
STARTING SYSTEM
Wiring DiagramINFOID:0000000001696232
AWBWA0140GB
Revision: March 20102008 QX56

TM-3
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P1752 INPUT CLUTCH SOLENOID .............. ....80
Description .......................................................... ....80
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
80
On Board Diagnosis Logic ......................................80
Possible Cause .......................................................80
DTC Confirmation Procedure ..................................80
Diagnosis Procedure ...............................................80
P1757 FRONT BRAKE SOLENOID ...................82
Description .......................................................... ....82
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
82
On Board Diagnosis Logic ......................................82
Possible Cause .......................................................82
DTC Confirmation Procedure ..................................82
Diagnosis Procedure ...............................................82
P1762 DIRECT CLUTCH SOLENOID ................84
Description .......................................................... ....84
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
84
On Board Diagnosis Logic ......................................84
Possible Cause .......................................................84
DTC Confirmation Procedure ..................................84
Diagnosis Procedure ...............................................84
P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID .........................................................
86
Description .......................................................... ....86
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
86
On Board Diagnosis Logic ......................................86
Possible Cause .......................................................86
DTC Confirmation Procedure ..................................86
Diagnosis Procedure ...............................................86
P1772 LOW COAST BRAKE SOLENOID .........88
Description .......................................................... ....88
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
88
On Board Diagnosis Logic ......................................88
Possible Cause .......................................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P1774 LOW COAST BRAKE SOLENOID .........90
Description .......................................................... ....90
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
90
On Board Diagnosis Logic ......................................90
Possible Cause .......................................................90
DTC Confirmation Procedure ..................................90
Diagnosis Procedure ...............................................90
MAIN POWER SUPPLY AND GROUND CIR-
CUIT ....................................................................
92
Diagnosis Procedure ........................................... ....92
CLOSED THROTTLE POSITION AND WIDE
OPEN THROTTLE POSITION CIRCUIT ...........
94
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
94
Diagnosis Procedure ...............................................94
BRAKE SIGNAL CIRCUIT ................................95
CONSULT-III Reference Va lue in Data Monitor
Mode .................................................................... ....
95
Diagnosis Procedure ...............................................95
TOW MODE SWITCH .......................................96
Description ...............................................................96
Diagnosis Procedure ...............................................96
A/T SHIFT LOCK SYSTEM ...............................97
Wiring Diagram - A/T Shift Lock System .................97
Terminals And Reference Values ..........................100
Component Description ....................................... ..100
ECU DIAGNOSIS .......................................103
TCM .................................................................103
Reference Value .................................................. ..103
Wiring Diagram — A/T CONTROL SYSTEM — .. ..105
Fail-Safe .............................................................. ..114
DTC Inspection Priority Chart ................................116
DTC No. Index .......................................................116
DTC Alphabetical Index .........................................117
SYMPTOM DIAGNOSIS ............................118
SYSTEM SYMPTOM .......................................118
A/T Check Indicator Lamp Does Not Come On ... ..118
Engine Cannot Be Started in "P" or "N" Position ...118
In "P" Position, Vehicle Moves When Pushed .......119
In "N" Position, Vehicle Moves ..............................119
Large Shock("N" to "D" Position) ...........................121
Vehicle Does Not Creep Backward in "R" Position ..123
Vehicle Does Not Creep Forward in "D" Position ..125
Vehicle Cannot Be Started from D1 ......................128
A/T Does Not Shift: D1→D2 ..................................130
A/T Does Not Shift: D2→ D3 ..................................131
A/T Does Not Shift: D3→ D4 ..................................133
A/T Does Not Shift: D4→ D5 ..................................135
A/T Does Not Perform Lock-up ........................... ..137
A/T Does Not Hold Lock-up Condition ...................139
Lock-up Is Not Released .......................................140
Engine Speed Does Not Return to Idle .................141
A/T Does Not Shift: 5GR → 4GR ........................ ..142
A/T Does Not Shift: 4GR → 3GR ........................ ..144
A/T Does Not Shift: 3GR → 2GR ........................ ..146
A/T Does Not Shift: 2GR → 1GR ........................ ..147
Vehicle Does Not Decelerate By Engine Brake ... ..149
Symptom Table .....................................................151
PRECAUTION ............................................173
PRECAUTIONS ...............................................173
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-21
< FUNCTION DIAGNOSIS >
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CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000001603991
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-4,
"System Description".
SENSORS (or SIGNALS)
⇒TCM
⇒ACTUATORS
Transmission range switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Output speed sensor
Vehicle speed signal
Stop lamp switch signal
Input speed sensor
1st position switch signal
4th position switch signal
ATF pressure switch 2 signal
Tow mode switch signal Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-III co
mmunication
line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch sole-
noid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Starter relay
Back-up lamp relay
JSDIA1315GB
Revision: March 2010
2008 QX56

TM-24
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000001603994
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-25
< FUNCTION DIAGNOSIS >
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*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000001603995
The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque conver ter 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.
Lock-up Applied
• In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
PCIA0013E
Select lever D position4 position 3 position 2 position
G ear p osit io n 54432
Lock-up ×– ×××
Slip lock-up ××–––
PCIA0014E
Revision: March 2010 2008 QX56

A/T SHIFT LOCK SYSTEMTM-97
< COMPONENT DIAGNOSIS >
CEF
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A/T SHIFT LOCK SYSTEM
Wiring Diagram - A/ T Shift Lock SystemINFOID:0000000001696153
ABDWA0334GB
Revision: March 2010 2008 QX56

TCM
TM-105
< ECU DIAGNOSIS >
C EF
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Wiring Diagram —A/T CONTROL SYSTEM —INFOID:0000000001604174
ABDWA0335GB
Revision: March 2010 2008 QX56

HEATER & COOLING UNIT ASSEMBLYVTL-17
< ON-VEHICLE REPAIR >
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1. Move the two front seats to the rear most position on the seat track.
2. Disconnect the battery negative terminal and battery positive terminal.
3. Discharge the refrigerant from the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
4. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Remove the instrument panel and console panel. Refer to IP-12, "
Removal and Installation".
8. Remove the steering column. Refer to ST-20, "
Removal and Installation".
9. Disconnect the instrument panel wire harness at t he RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-9, "
Wiring Diagram — Battery Power Supply —".
10. Disconnect the steering member from each side of the vehicle body.
11. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi- cle.
CAUTION:
Use care not to damage the seats and interior trim panels when removing the front heater and
cooling unit assembly with it at tached to the steering member.
12. Remove the front heater and cooling uni t assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com-
pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
3. Remove the luggage side finisher lower RH. Refer to INT-19, "
Removal and Installation".
4. Disconnect the rear heater core hoses from the rear heater core.
5. Disconnect the rear A/C pipes from the rear expansion valve.
6. Disconnect the following electrical connectors: • Rear blower motor
• Rear variable blower control
• Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com- pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
Revision: March 2010 2008 QX56