diagram INFINITI QX56 2008 Factory Repair Manual

DLN-2
P1820 ENGINE SPEED SIGNAL ......................52
Description ........................................................... ...52
DTC Logic ...............................................................52
Diagnosis Procedure ..............................................52
P1822 CLUTCH PRESSURE SOLENOID .........53
Description ..............................................................53
DTC Logic ...............................................................53
Diagnosis Procedure ..............................................53
Component Inspection ............................................55
P1823 2-4 SOLENOID .......................................57
Description ........................................................... ...57
DTC Logic ...............................................................57
Diagnosis Procedure ..............................................57
Component Inspection ............................................60
P1824 TRANSFER MOTOR ..............................61
Description ..............................................................61
DTC Logic ...............................................................61
Diagnosis Procedure ..............................................61
Component Inspection ............................................65
P1826 TRANSFER FLUID TEMPERATURE ....67
Description ........................................................... ...67
DTC Logic ...............................................................67
Diagnosis Procedure ..............................................67
Component Inspection ............................................68
P1827 CLUTCH PRESSURE SWITCH .............70
Description ........................................................... ...70
DTC Logic ...............................................................70
Diagnosis Procedure ..............................................70
Component Inspection ............................................71
P1828 LINE PRESSURE SWITCH ....................73
Description ........................................................... ...73
DTC Logic ...............................................................73
Diagnosis Procedure ..............................................73
Component Inspection ............................................75
P1829 THROTTLE POSITION SIGNAL (ECM)
...
76
Description ........................................................... ...76
DTC Logic ...............................................................76
Diagnosis Procedure ..............................................76
P1830 ABS OPERATION SIGNAL (ABS) ........77
Description ........................................................... ...77
DTC Logic ...............................................................77
Diagnosis Procedure ..............................................77
P1831 VDC OPERATION SIGNAL (ABS) ........78
Description ........................................................... ...78
DTC Logic ...............................................................78
Diagnosis Procedure ..............................................78
P1832 TCS OPERATION SIGNAL (ABS) .........79
Description ........................................................... ...79
DTC Logic ...............................................................79
Diagnosis Procedure ..............................................79
ECU DIAGNOSIS .......................................80
TRANSFER CONTROL UNIT ...........................80
Reference Value .................................................. ...80
Wiring Diagram .......................................................88
DTC Index ...............................................................95
SYMPTOM DIAGNOSIS ...........................100
4WD SYSTEM SYMPTOMS ........................... ..100
Symptom Table .................................................... .100
4WD SHIFT INDICATOR LAMP AND 4LO IN-
DICATOR LAMP DO NOT TURN ON ..............
101
Description ............................................................101
Diagnosis Procedure .............................................101
4WD WARNING LAMP DOES NOT TURN ON ..103
Description ........................................................... .103
Diagnosis Procedure .............................................103
4WD SHIFT INDICATOR LAMP OR 4LO INDI-
CATOR LAMP DO NOT CHANGE ...................
105
Description ........................................................... .105
Diagnosis Procedure .............................................105
ATP WARNING LAMP DOES NOT TURN ON ..107
Description ........................................................... .107
Diagnosis Procedure .............................................107
4WD SHIFT INDICATOR LAMP KEEPS
FLASHING ........................................................
109
Description ........................................................... .109
Diagnosis Procedure .............................................109
4WD WARNING LAMP FLASHES RAPIDLY ..110
Description ............................................................110
Diagnosis Procedure .............................................110
4WD WARNING LAMP FLASHES SLOWLY ..111
Description ............................................................111
Diagnosis Procedure .............................................111
HEAVY TIGHT-CORNER BRAKING SYMP-
TOM OCCURS ................................................ ..
112
Description ........................................................... .112
Diagnosis Procedure .............................................112
ATP SWITCH ....................................................114
Description ........................................................... .114
Diagnosis Procedure .............................................114
4WD SYSTEM DOES NOT OPERATE ............116
Description ........................................................... .116
Diagnosis Procedure .............................................116
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ...........................
117
NVH Troubleshooting Chart ..................................117
PRECAUTION ............... ............................118
Revision: March 2010 2008 QX56

DLN-10
< FUNCTION DIAGNOSIS >[ATX14B]
4WD SYSTEM
FUNCTION DIAGNOSIS
4WD SYSTEM
System DiagramINFOID:0000000001737096
COMPONENT DESCRIPTION
WDIA0164E
Components
Function
Transfer control unit Controls transfer control device, control valves and shifts between 2WD/4WD and 4H/4LO.
Transfer control device Integrates actuator motor and actuator position switch.
2-4WD shift solenoid valve Controls oil pressure and allows shifting between 2WD and 4WD.
Clutch pressure solenoid valve Controls oil pressure and distributes torque between front and rear tires.
Line pressure switch Detects line pressure.
Clutch pressure switch Detects clutch pressure.
Transfer fluid temperature sensor Detects transfer fluid temperature.
Actuator motor Moves shift rods when signaled by transfer control unit.
Actuator position switch Detects actuator motor position.
Wait detection switch Detects whether or not 4WD lock gear is locked.
4LO switch Detects if transfer case is in 4LO.
ATP switch Detects if transfer case is in neutral.
4WD shift switch Allows driver to select from 2WD/4WD, 4H/4LO and AUTO.
4WD warning lamp • Illuminates if malfunction is detected in 4WD system.
• Flashes (1 flash / 2 seconds) if large difference in diameter of front and rear tires.
• Flashes (2 flashes / 1 second) if high transfer fluid temperature is detected.
AT P w a r n i n g l a m p Indicates that A/T parking mechanism does not operate when A/T selector lever is in P position
because transfer case is in neutral.
4WD shift indicator lamp Displays driving range selected by 4WD shift switch.
4LO indicator lamp Displays 4LO range.
Revision: March 2010 2008 QX56

DLN-88
< ECU DIAGNOSIS >[ATX14B]
TRANSFER CONTROL UNIT
Wiring Diagram
INFOID:0000000001737180
AADWA0054GB
Revision: March 2010 2008 QX56

EC-1
ENGINE
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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
VK56DE
BASIC INSPECTION ....... .............................
8
DIAGNOSIS AND REPAIR WORKFLOW ..... .....8
Trouble Diagnosis Introduction ........................... ......8
INSPECTION AND ADJUSTMENT ....................13
Basic Inspection .................................................. ....13
Idle Speed and Ignition Timing Check ....................17
Procedure After Replacing ECM .............................17
VIN Registration ......................................................17
Accelerator Pedal Released Position Learning .......18
Throttle Valve Closed Position Learning .................18
Idle Air Volume Learning .........................................18
FUNCTION DIAGNOSIS ..............................21
ENGINE CONTROL SYSTEM ........................ ....21
System Diagram .................................................. ....21
Engine Control Component Parts Location .............22
MULTIPORT FUEL INJECTION SYSTEM ..... ....28
System Description ............................................. ....28
ELECTRIC IGNITION SYSTEM ..................... ....31
System Description ............................................. ....31
AIR CONDITIONING CUT CONTROL ...............32
Input/Output Signal Chart .................................... ....32
System Description .................................................32
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
33
System Description ............................................. ....33
Component Description ...........................................34
CAN COMMUNICATION ....................................35
System Description ............................................. ....35
COOLING FAN CONTROL ................................36
Description ..............................................................36
EVAPORATIVE EMISSION SYSTEM ...............37
Description ........................................................... ....37
INTAKE VALVE TIMING CONTROL ................40
Description ...............................................................40
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....41
Introduction ..............................................................41
Two Trip Detection Logic .........................................41
Emission-related Diagnostic Information .................42
Malfunction Indicator Lamp (MIL) ............................55
OBD System Operation Chart .................................58
CONSULT-III Function (ENGINE) ...........................63
Generic Scan Tool (GST) Function .........................72
COMPONENT DIAGNOSIS .........................75
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
75
Description ........................................................... ....75
Testing Condition .....................................................75
Inspection Procedure ...............................................75
Diagnosis Procedure ...............................................76
POWER SUPPLY AND GROUND CIRCUIT ....83
Diagnosis Procedure ...............................................83
Ground Inspection ...................................................86
U1000, U1001 CAN COMM CIRCUIT ...............87
Description ...............................................................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................87
U1010 CONTROL UNIT (CAN) .........................88
Description ...............................................................88
On Board Diagnosis Logic .......................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P0011, P0021 IVT CONTROL ...........................90
On Board Diagnosis Logic .......................................90
Revision: March 2010 2008 QX56

EC-6
Component Description .........................................359
On Board Diagnosis Logic .....................................359
DTC Confirmation Procedure ................................359
Diagnosis Procedure .............................................360
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
362
Description ........................................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................365
P2118 THROTTLE CONTROL MOTOR ..........366
Component Description ....................................... ..366
On Board Diagnosis Logic .....................................366
DTC Confirmation Procedure ................................366
Diagnosis Procedure .............................................366
Component Inspection ...........................................367
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
368
Component Description ....................................... ..368
On Board Diagnosis Logic .....................................368
DTC Confirmation Procedure ................................368
Diagnosis Procedure .............................................369
P2122, P2123 APP SENSOR ..........................370
Component Description ....................................... ..370
On Board Diagnosis Logic .....................................370
DTC Confirmation Procedure ................................370
Diagnosis Procedure .............................................371
Component Inspection ...........................................372
P2127, P2128 APP SENSOR ..........................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................373
Component Inspection ...........................................376
P2135 TP SENSOR .........................................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................377
Component Inspection ...........................................380
P2138 APP SENSOR ......................................381
Component Description ....................................... ..381
On Board Diagnosis Logic .....................................381
DTC Confirmation Procedure ................................381
Diagnosis Procedure .............................................382
Component Inspection ...........................................384
P2A00, P2A03 A/F SENSOR 1 .......................385
Component Description ....................................... ..385
On Board Diagnosis Logic .....................................385
DTC Confirmation Procedure ................................385
Diagnosis Procedure .............................................386
ASCD BRAKE SWITCH ...................................390
Component Description ....................................... .390
Diagnosis Procedure .............................................390
Component Inspection ..........................................393
ASCD INDICATOR ...........................................394
Component Description ....................................... .394
Diagnosis Procedure .............................................394
COOLING FAN .................................................395
Diagnosis Procedure ............................................ .395
Component Inspection ..........................................395
ELECTRICAL LOAD SIGNAL ..........................397
Description ........................................................... .397
Diagnosis Procedure .............................................397
FUEL INJECTOR ..............................................399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................401
FUEL PUMP .....................................................402
Description ........................................................... .402
Diagnosis Procedure .............................................402
Component Inspection ..........................................405
ICC BRAKE SWITCH ..................................... ..406
Component Description ....................................... .406
Diagnosis Procedure .............................................406
Component Inspection ..........................................409
IGNITION SIGNAL ............................................411
Component Description ....................................... .411
Diagnosis Procedure .............................................411
Component Inspection ..........................................414
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
416
System Description .............................................. .416
Diagnosis Procedure .............................................416
Component Inspection ..........................................418
POSITIVE CRANKCASE VENTILATION .........421
Description ........................................................... .421
Component Inspection ..........................................421
REFRIGERANT PRESSURE SENSOR ...........423
Component Description ....................................... .423
Diagnosis Procedure .............................................423
ECU DIAGNOSIS ......................................426
ECM ................................................................ ..426
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
426
ECM Harness Connector Terminal Layout ...........429
ECM Terminal and Reference Value ....................429
Wiring Diagram - ENGINE CONTROL SYSTEM - .439
Fail-Safe Chart ......................................................459
DTC Inspection Priority Chart ...............................461
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTEC-15
< BASIC INSPECTION > [VK56DE]
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EC
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1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-211
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-207
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace. 2. GO TO 4.
9.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM f unction. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NAT S) system and registration of all IVIS (NATS) ignition key IDs. Refer to
SEC-13, "
System Diagram".
>> GO TO 4.
10.CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11 .PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-18, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-18, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning. 650
± 50 rpm (in P or N position)
15 ± 5 ° BTDC (in P or N position)
BBIA0379E
Revision: March 2010 2008 QX56

EC-16
< BASIC INSPECTION >[VK56DE]
INSPECTION AND ADJUSTMENT
2. GO TO 4.
14.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-III.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light. Refer to EC-17, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-45, "
Removal and Installation".
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation. 2. GO TO 4.
17.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-211
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-207
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace. 2. GO TO 4.
18.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but this is a rare case.)
2. Perform initialization of IVIS (NATS) system and regist ration of all IVIS (NATS) ignition key IDs. Refer to
SEC-13, "
System Diagram".
>> GO TO 4.
19.INSPECTION END 650
± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
15 ± 5 ° BTDC (in P or N position)
BBIA0379E
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTEC-17
< BASIC INSPECTION > [VK56DE]
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Did you replace ECM, referring this Basic Inspection procedure?
Ye s o r N o
Ye s > > 1 . P e r f o r m
EC-17, "VIN Registration" .
2. INSPECTION END
No >> INSPECTION END
Idle Speed and Ignition Timing CheckINFOID:0000000001351330
IDLE SPEED
With CONSULT-III
Check idle speed in “DATA MONITOR” mode with CONSULT-III.
With GST
Check idle speed with GST.
IGNITION TIMING
1. Attach timing light to loop wire as shown.
2. Check ignition timing.
Procedure After Replacing ECMINFOID:0000000001351331
When replacing ECM, the following procedure must be performed.
1. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs.
Refer to SEC-13, "
System Diagram".
2. Perform EC-17, "
VIN Registration".
3. Perform EC-18, "
Accelerator Pedal Released Position Learning".
4. Perform EC-18, "
Throttle Valve Closed Position Learning".
5. Perform EC-18, "
Idle Air Volume Learning".
VIN RegistrationINFOID:0000000001351332
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE
BBIA0377E
BBIA0379E
Revision: March 2010 2008 QX56

ENGINE CONTROL SYSTEMEC-21
< FUNCTION DIAGNOSIS > [VK56DE]
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FUNCTION DIAGNOSIS
ENGINE CONTROL SYSTEM
System DiagramINFOID:0000000001351344
PBIB3438E
Revision: March 2010
2008 QX56

POWER SUPPLY AND GROUND CIRCUITEC-83
< COMPONENT DIAGNOSIS > [VK56DE]
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POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000001351355
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Yes >> GO TO 8.
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• 10A fuse
• Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power. Voltage: Battery voltage
MBIB0015E
BBIA0354E
Continuity should exist.
Revision: March 2010
2008 QX56