2011 INFINITI QX56 power steering

CYLINDER HEADEM-95
< REMOVAL AND INSTALLATION >
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If hydraulic pressure inside chain tensioner drops after removal/installation, slack in guide may generate a
pounding noise during and just after the engine start. However, this does not indicate a malfunction. The
noise will stop after hydraulic pressure rises.
 Warm up engine thoroughly to check that there is no leak age of fuel, or any oil/fluids including engine oil and
engine coolant.
 Bleed air from lines and hoses of applicable lines, such as in cooling system.
 After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to
the specified level, if necessary.
Summary of the inspection items:
* Power steering fluid, brake fluid, etc. Items Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Transmission /
transaxle fluid AT & CVT Models Leakage Level / Leakage Leakage
MT Models Level / Leakage Leakage Level / Leakage
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Revision: 2010 May2011 QX56

ENGINE ASSEMBLYEM-99
< UNIT REMOVAL AND INSTALLATION >
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4WD models
Removal and InstallationINFOID:0000000006289577
WARNING:
 Situate the vehicle on a flat and solid surface.
 Place chocks at the front
and back of rear wheels.
 For engines not equipped with engi ne slingers, attach proper slingers and bolts described in PARTS
CATALOG.
CAUTION:
 Always be careful to work safely, and avo id forceful or uninstructed operations.
 Never start working until exhaust system and engine coolant are cool enough.
 If items or work required are not covered by th e engine section, refer to the applicable sections.
 Always use the support poin t specified for lifting.
 Use either 2-pole lift type or separate type lift as much as possible. If board-on type is used for
unavoidable reasons, support at r ear axle jacking point with transmi ssion jack or similar tool before
starting work, in preparat ion for the backward shift of the center of gravity.
 For supporting points fo r lifting and jacking point at rear axle, refer to GI-32, "
Garage Jack and
Safety Stand".
NOTE:
When removing/installing only the engine mounting, the hold engine assembly as instructed bellow:
1. Remove hood assembly. Refer to DLK-215, "
Exploded View".
2. Remove the following components and related parts:  Battery. Refer to PG-164, "
Exploded View".
 Battery tray.
 Power steering reservoir tank bracket. Refer to ST-54, "
Exploded View".
 Air cleaner case assembly and air duct. Refer to EM-27, "
Exploded View".
JPBIA4256GB
1. Heat shield plate (RH) 2. Engine mounting insulator (RH) 3. Engine mounting bracket (RH)
4. Engine mounting bracket (LH) 5. Engine mounting insulator (LH) 6. Heat shield plate (LH)
7. Rear engine mounting cross member 8. Rear engine mounting insulator 9. Dynamic damper
Refer to GI-4, "
Components" for symbols in the figure.
Revision: 2010 May2011 QX56

EM-100
< UNIT REMOVAL AND INSTALLATION >
ENGINE ASSEMBLY
3. Install engine slinger on both front right and front left sides of theengine.
4. Hoist the slinger to obtain room for engine assembly. CAUTION:
Use an engine lifter to prevent the engine slinger from fall-
ing and damaging the rocker cover.
REMOVAL
Outline
At first, remove the transmission and transfer assemb ly, steering gear and front final drive facing downward.
Then remove the engine.
Preparation
1. Remove engine cover. Refer to EM-25, "Exploded View".
2. Release fuel pressure. Refer to EC-153, "
Work Procedure".
3. Remove battery and tray. Refer to PG-164, "
Exploded View".
4. Remove the following components and related parts:  Hood assembly. Refer to DLK-215, "
Exploded View".
 Front under cover. Refer to EXT-25, "
Exploded View".
 Front road wheel and tires. Refer to WT-64, "
Exploded View".
5. Drain engine oil. Refer to LU-8, "
Draining".
6. Drain engine coolant. Refer to CO-8, "
Draining".
CAUTION:
 Perform this step when engine is cold.
 Never spill engine coolant on drive belts.
7. Drain power steering fluid. Refer to ST-54, "
Exploded View".
Engine Room Front
1. Remove drive belt. Refer to EM-20, "Exploded View".
2. Remove fan shroud. Refer to CO-13, "
Exploded View".
3. Remove cooling fan and fan coupling. Refer to CO-16, "
Exploded View".
4. Remove radiator hoses (upper and lower).
5. Remove radiator.
Vehicle Underbody
1. Remove exhaust front tube. Refer to EX-5, "Exploded View".
2. Remove protector A and B. Refer to SCS-32, "
FRONT TUBE ASSEMBLY : Exploded View".
3. Remove front suspension rear cross member. Refer to TM-205, "
2WD : Exploded View" (2WD models) or
TM-208, "
4WD : Exploded View" (4WD models).
4. Remove oil cooler. Refer to LU-11, "
Exploded View".
A : Engine front slinger (bank 2)
B : Engine front slinger (bank 1)
Slinger bolts:
: 45.0 N·m (4.6 kg-m, 33 ft-lb)
JPBIA3969ZZ
JPBIA2507ZZ
Revision: 2010 May2011 QX56

ENGINE ASSEMBLYEM-101
< UNIT REMOVAL AND INSTALLATION >
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5. Remove A/T assembly. Refer to
TM-205, "2WD : Exploded View" (2WD models) or TM-208, "4WD :
Exploded View" (4WD models).
6. Remove steering gear assembly. Refer to ST-41, "
Exploded View".
7. Remove front final drive assembly. Refer to DLN-162, "
Exploded View".
8. Remove exhaust manifold. Refer to EM-40, "
Exploded View".
9. Remove alternator. Refer to CHG-25, "
Exploded View".
Engine Room LH
1. Remove air cleaner and air duct. Refer to EM-27, "Exploded View".
2. Remove A/C compressor. Refer to HA-30, "
Exploded View".
3. Disconnect fuel feed hose and EVAP hose. Refer to EM-43, "
Exploded View".
CAUTION:
Fit plugs onto disconnected hoses to prevent fuel leakage.
Engine Room RH
1. Remove power steering oil pump and reservoir tank. Refer to ST-48, "Exploded View".
2. Disconnect heater hose at heater core side, and fit a plug onto hose end to prevent engine coolant leak-
age.
3. Disconnect ground cable.
4. Disconnect all clips and connectors of the engine harness from vehicle side.
Removal Work
1. Install alternator bracket. Refer to CHG-25, "Exploded View".
 Temporarily tighten mounting bolts.
2. Remove intake manifold. Refer to EM-30, "
Exploded View".
3. Remove starter motor. Refer to STR-17, "
Exploded View".
4. Install engine slingers.
5. Lift using a hoist and secure the engine in position.
6. Remove engine mounting bracket (LH, RH) and engine mounting insulator (LH, RH). Refer to EM-98,
"Exploded View".
7. Remove the engine from the vehi cle, avoid interference with the
vehicle body.
CAUTION:
 Before and during lifting, always check that any har-
nesses are left connected.
 Never damage engine mounti ng insulator and avoid oil/
grease smearing or spills onto engine mounting insulator.
A Engine front slinger (bank 2) B Engine rear slinger C Engine front slinger (bank 1)
Slinger bolts:
: 45.0 N·m (4.6 kg-m, 33 ft-lb)
JPBIA3970ZZ
JPBIA3497ZZ
Revision: 2010 May2011 QX56

EM-102
< UNIT REMOVAL AND INSTALLATION >
ENGINE ASSEMBLY
INSTALLATION
Install in the reverse order of removal.
CAUTION:
 When replacing an engine or transmission you must make sure the dowels are installed correctly
during re-assembly.Improper alignment caused by mi ssing dowels may cause vibration, oil leaks or
breakage of drivetrain components.
InspectionINFOID:0000000006289578
INSPECTION AFTER INSTALLATION
Inspection for Leakage
The following are procedures for checking fluid leakage, lubricant leakage. Before starting engine, check oil/fluid levels includi ng engine coolant and engine oil. If any are less than the
required quantity, fill them to the specified level. Refer to MA-10, "
Fluids and Lubricants".
 Follow the procedure below to check for fuel leakage.
- Turn ignition switch to the “ON” position (with engi ne stopped). With fuel pressure applied to fuel piping,
check for fuel leakage at connection points.
- Start engine. With engine speed increased, che ck again for fuel leakage at connection points.
 Run engine to check for unusual noise and vibration. NOTE:
If hydraulic pressure inside chain tensioner drops af ter removal/installation, slack in guide may generate a
pounding noise during and just after the engine start. However, this does not indicate a malfunction. The
noise will stop after hydraulic pressure rises.
 Warm up engine thoroughly to check that there is no leak age of fuel, or any oil/fluids including engine oil and
engine coolant.
 Bleed air from lines and hoses of applic able lines, such as in cooling system.
 After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to
the specified level, if necessary.
Summary of the inspection items:
*: Power steering fluid, brake fluid, etc. Items Before starting engine Engine running After engine stopped
Engine coolant Level Leakage Level
Engine oil Level Leakage Level
Transmission /
transaxle fluid AT & CVT Models Leakage Level / Leakage Leakage
MT Models Level / Leakage Leakage Level / Leakage
Other oils and fluids* Level Leakage Level
Fuel Leakage Leakage Leakage
Exhaust gases — Leakage —
Revision: 2010 May2011 QX56

EXL-2
EXTERIOR LAMP BATTERY SAVER SYSTEM :
System Description .................................................
21
DIAGNOSIS SYSTEM (BCM) ............................22
COMMON ITEM ..................................................... ...22
COMMON ITEM : CONSULT-III Function (BCM -
COMMON ITEM) ................................................. ...
22
HEADLAMP ........................................................... ...23
HEADLAMP : CONSULT-III Function (BCM -
HEAD LAMP) ..........................................................
23
FLASHER ............................................................... ...25
FLASHER : CONSULT-III Function (BCM -
FLASHER) ..............................................................
25
DIAGNOSIS SYSTEM (IPDM E/R) ....................27
Diagnosis Description .......................................... ...27
CONSULT-III Function (IPDM E/R) ........................29
DIAGNOSIS SYSTEM (AFS) .............................32
CONSULT-III Function (ADAPTIVE LIGHT) ........ ...32
ECU DIAGNOSIS INFORMATION ..............34
BCM, IPDM E/R .............................................. ...34
List of ECU Reference ......................................... ...34
AFS CONTROL UNIT ........................................35
Reference Value .................................................. ...35
Fail-Safe .................................................................38
DTC Inspection Priority Chart .................................39
DTC Index ..............................................................39
WIRING DIAGRAM .....................................40
EXTERIOR LIGHTING SYSTEM .................... ...40
Wiring Diagram .................................................... ...40
BASIC INSPECTION ...................................59
DIAGNOSIS AND REPAIR WORKFLOW ...... ...59
Work Flow ............................................................ ...59
INSPECTION AND ADJUSTMENT ...................61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) .............. ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) : De-
scription ..................................................................
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (AFS CONTROL UNIT) : Special
Repair Requirement ...............................................
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) ................... ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) : Descrip-
tion ....................................................................... ...
61
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (HEIGHT SENSOR) : Special
Repair Requirement ............................................. ...
61
LEVELIZER ADJUSTMENT ......................................61
LEVELIZER ADJUSTMENT : Description ..............61
LEVELIZER ADJUSTMENT : Special Repair Re-
quirement ............................................................. ...
61
DTC/CIRCUIT DIAGNOSIS ........................63
B2503, B2504 SWIVEL ACTUATOR ............. ...63
DTC Logic ............................................................ ...63
Diagnosis Procedure ...............................................64
Component Inspection ............................................67
B2513 HEIGHT SENSOR UNUSUAL [FR] .......68
DTC Logic ............................................................ ...68
Diagnosis Procedure ...............................................68
B2514 HEIGHT SENSOR UNUSUAL [RR] .......71
DTC Logic ............................................................ ...71
Diagnosis Procedure ...............................................71
B2516 SHIFT SIGNAL [P, R] ............................74
DTC Logic ............................................................ ...74
Diagnosis Procedure ...............................................74
B2517 VEHICLE SPEED SIGNAL ....................75
DTC Logic ............................................................ ...75
Diagnosis Procedure ...............................................75
B2519 LEVELIZER CALIBRATION ..................76
DTC Logic ............................................................ ...76
Diagnosis Procedure ...............................................76
B2521 ECU CIRCUIT ........................................77
DTC Logic ............................................................ ...77
Diagnosis Procedure ...............................................77
C0126 STEERING ANGLE SENSOR SIGNAL ...80
DTC Logic ............................................................ ...80
Diagnosis Procedure ...............................................80
C0428 STEERING ANGLE SENSOR CALI-
BRATION ...........................................................
81
DTC Logic ............................................................ ...81
Diagnosis Procedure ...............................................81
U1000 CAN COMM CIRCUIT ............................82
Description ........................................................... ...82
DTC Logic ...............................................................82
Diagnosis Procedure ...............................................82
U1010 CONTROL UNIT (CAN) .........................83
DTC Logic ............................................................ ...83
Diagnosis Procedure ...............................................83
POWER SUPPLY AND GROUND CIRCUIT .....84
AFS CONTROL UNIT ............................................. ...84
AFS CONTROL UNIT : Diagnosis Procedure .........84
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (BCM)EXL-23
< SYSTEM DESCRIPTION > [XENON TYPE]
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HEADLAMP
HEADLAMP : CONSULT-III Func tion (BCM - HEAD LAMP)INFOID:0000000006213911
WORK SUPPORT
CONSULT screen item Indication/Unit Description
Vehicle Speed km/h Vehicle speed of the moment a particular DTC is detected
Odo/Trip Meter km Total mileage (Odometer value) of the moment a particular DTC is detected
Vehicle Condition SLEEP>LOCK
Power position status of
the moment a particular
DTC is detected While turning BCM status from low power consumption mode to
normal mode (Power supply position is “LOCK”)
SLEEP>OFF While turning BCM status from low power consumption mode to
normal mode (Power supply position is “OFF”.)
LOCK>ACC While turning power supply position from “LOCK” to “ACC”
ACC>ON While turning power supply position from “ACC” to “IGN”
RUN>ACC While turning power supply position
from “RUN” to “ACC” (Vehicle
is stopping and selector lever is except P position.)
CRANK>RUN While turning power su
pply position from “CRANKING” to “RUN”
(From cranking up the engine to run it)
RUN>URGENT While turning power su
pply position from “RUN“ to “ACC” (Emer-
gency stop operation)
ACC>OFF While turning power supply position from “ACC” to “OFF”
OFF>LOCK While turning power supply position from “OFF” to “LOCK”
OFF>ACC While turning power supply position from “OFF” to “ACC”
ON>CRANK While turning po wer supply position from “IGN” to “CRANKING”
OFF>SLEEP While turning BCM status from normal mode (Power supply posi-
tion is “OFF”.) to low power consumption mode
LOCK>SLEEP While turning BCM status from normal mode (Power supply posi-
tion is “LOCK”.) to low power consumption mode
LOCK Power supply position is “LOCK” (Ignition switch OFF with steer-
ing is locked.)
OFF Power supply position
is “OFF” (Ignition switch OFF with steering
is unlocked.)
ACC Power supply position is “ACC” (Ignition switch ACC)
ON Power supply position is “IGN” (Ignition switch ON with engine
stopped)
ENGINE RUN Power supply posi
tion is “RUN” (Ignition switch ON with engine
running)
CRANKING Power supply position is “CRANKING” (At engine cranking)
IGN Counter 0 - 39 The number of times that ignition switch is turned ON after DTC is detected
 The number is 0 when a malfunction is detected now.
 The number increases like 1
→ 2 → 3...38 → 39 after returning to the normal condition
whenever ignition switch OFF → ON.
 The number is fixed to 39 until the self-diagnosis results are erased if it is over 39.
Service item Setting item Setting
CUSTOM A/LIGHT SETTING MODE 1*
1Normal
MODE 2 More sensitive setting than normal setting (Turns ON earlier than normal opera-
tion)
MODE 3 More sensitive setting than MODE 2 (Turns ON earlier than MODE 2)
MODE 4 Less sensitive setting than normal setting (Turns ON later than normal operation)
Revision: 2010 May2011 QX56

PRECAUTIONSEXT-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006367589
The Supplemental Restraint System such as “A IR 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 “SRS AIR BAG”.
 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 Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric 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 Wh eel Rotation after Battery Disconnect
INFOID:0000000006367590
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56