2008 INFINITI QX56 wiring

PRECAUTIONSDLN-233
< PRECAUTION > [REAR FINAL DRIVE: R230]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004857594
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 severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, 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 in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wheel Rotation After Battery Disconnect
INFOID:0000000004857593
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecti ng both battery cables with the ignition knob in the
″ LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS , an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
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

EC-8
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or
other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-III (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on "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 incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTEC-13
< BASIC INSPECTION > [VK56DE]
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INSPECTION AND ADJUSTMENT
Basic InspectionINFOID:0000000001351329
1.INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
2. Open engine hood and check the following:
- Harness connectors for improper connections
- Wiring harness for improper connections, pinches and cut
- Vacuum hoses for splits, kinks and improper connections
- Hoses and ducts for leaks
- Air cleaner clogging
- Gasket
3. Confirm that electrical or mechanical loads are not applied.
- Headlamp switch is OFF.
- Air conditioner switch is OFF.
- Rear window defogger switch is OFF.
- Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no load.
6. Make sure that no DTC is displayed with CONSULT-III or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
3.CHECK TARGET IDLE SPEED
With CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
SEF983U
SEF976U
SEF977U
Revision: March 2010 2008 QX56

CAN COMMUNICATIONEC-35
< FUNCTION DIAGNOSIS > [VK56DE]
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CAN COMMUNICATION
System DescriptionINFOID:0000000001351240
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.
Refer to LAN-44, "
CAN System Specification Chart", about CAN communication for detail.
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

POWER SUPPLY AND GROUND CIRCUITEC-85
< COMPONENT DIAGNOSIS > [VK56DE]
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Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
11 .CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 111 and IPDM E/R terminal 7. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK 20A FUSE
1. Disconnect 20A fuse from IPDM E/R.
2. Check 20A fuse.
OK or NG
OK >> GO TO 16.
NG >> Replace 20A fuse.
13.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-86, "
Ground Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Repair or replace ground connections.
14.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
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.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.DETECT MALFUNCTIONING PART Continuity should exist.
Continuity should exist.
BBIA0354E
Continuity should exist.
Revision: March 2010
2008 QX56

U1000, U1001 CAN COMM CIRCUITEC-87
< COMPONENT DIAGNOSIS > [VK56DE]
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U1000, U1001 CAN COMM CIRCUIT
DescriptionINFOID:0000000001351359
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.
On Board Diagnosis LogicINFOID:0000000001351360
*1: This self-diagnosis has the one trip detection logic.
*2: The MIL will not light up for this self-diagnosis.
*3: This self-diagnosis has the one or two trip detection logic (Models with ICC)
DTC Confirmation ProcedureINFOID:0000000001351361
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-87, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001351363
Go to LAN-44, "CAN Communication Signal Chart".
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
U1000*
1
1000*1
CAN communication line When ECM is not transmitting or receiving CAN
communication signal of OBD (emission-relat-
ed diagnosis) for 2 seconds or more.
• Harness or connectors
(CAN communication line is open or
shorted)
U1001*2*3
1001*2*3
When ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion related diagnosis) for 2 seconds or more.
Revision: March 2010 2008 QX56