2011 INFINITI QX56 steering

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

COMPONENT PARTSEXL-7
< SYSTEM DESCRIPTION > [XENON TYPE]
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*1: With headlamp aiming control system (manual) models
*2: With AFS system models
EXTERIOR LIGHTING SYSTEM : Component DescriptionINFOID:0000000006213888
1. Combination meter 2. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
3. Optical sensor
4. IPDM E/R Refer to PCS-4, "
Component Parts
Location"
5. ECM
Refer to EC-16, "
Component Parts
Location"
6. Parking lamp
7. Front turn signal lamp 8. Front fog lamp 9. Headlamp
10. Front side marker lamp 11. Combination switch 12. Headlamp aiming switch*
1
13. Front door switch (driver side) 14.
Steering angle sensor*2
Refer to BRC-10, "Component Parts
Location"
15. License plate lamp
16. Tail lamp 17. Rear turn signal lamp 18. Rear side marker lamp
19. Hazard switch 20. Side turn signal lamp 21. Headlamp swivel actuator
22. Headlamp aiming motor 23. AFS switch*
224.Rear height sensor*2
25.AFS control unit*226.Front height sensor*2
A. Front combination lamp (back) B. View with instrument driver lower
panel (LH)C. Rear suspension member (RH)
D. View with instrument lower cover E. Front suspension arm (RH)
Part Description
BCM Controls the exterior lighting system.
ECM*
1Transmits engine speed signal to AFS control unit. (via CAN communication)
TCM*
1Transmits Shift position signal to AFS control unit. (via CAN communication)
IPDM E/R Controls the integrated relay, and supplies voltage to the load according to the request
from BCM (via CAN communication).
AFS control unit*
1AFS control unit judges the vehicle condition from each signal. AFS control unit con-
trols AFS function and the headlamp aiming.
Combination meter  Outputs the vehicle speed signal (8-pulse) to AFS control unit.
 Blinks the turn signal indicator lamp and outputs the turn signal operating sound with
integrated buzzer according to the request from BCM (via CAN communication).
 Turns the tail lamp indicator lamp and high beam indicator lamp ON according to the
request from BCM (via CAN communication).
 Turns the AFS OFF indicator lamp ON/OFF /blinking according to the request from
AFS control unit (via CAN communication).
Headlamp assembly Xenon bulb Refer to
EXL-8, "
FRONT COMBINATION LAMP : Xenon Headlamp".
HID control unit Refer to EXL-9, "
FRONT COMBINATION LAMP : HID control unit".
High beam solenoid Refer to EXL-9, "
FRONT COMBINATION LAMP : High Beam Solenoid".
Aiming motor Refer to EXL-9, "
FRONT COMBINATION LAMP : Aiming Motor".
Swivel actuator*
1Refer to EXL-9, "FRONT COMBINATION LAMP : Swivel Actuator".
Height sensor*
1
 The height sensor is installed to the front suspension member and rear suspension member.
 The height sensor detects the suspension arm displacement as the vehicle height change.
 The height sensor transmits the height sensor signal to AFS control unit.
NOTE:
The sensor angle of the unloaded vehicle position is the reference value.
Optical sensor Optical sensor converts the outside brightness (lux) to voltage and transmits the opti-
cal sensor signal to BCM.
Revision: 2010 May2011 QX56

EXL-8
< SYSTEM DESCRIPTION >[XENON TYPE]
COMPONENT PARTS
*1: With AFS system models
*
2: With headlamp aiming control system (manual) models
FRONT COMBINATION LAMP
FRONT COMBINATION LAMP : Xenon HeadlampINFOID:0000000006213889
OUTLINE
 The lamp light source is by the arch discharge by
applying high voltage into the xenon gas-filled bulb instead
of the halogen bulb filament.
 Sight becomes more natural and brighter because the amount of light are gained adequately and the color of
light is sunshine-like white.
 The xenon bulb drops the amount of light, repeats blinking, and illuminates in red if the bulb reaches the ser-
vice life.
ILLUMINATION PRINCIPLE
1. Discharging starts in high voltage pulse between bulb elec- trodes.
2. Xenon gas is activated by curr ent between electrodes. Pale light
is emitted.
3. The luminous tube (bulb) temperature elevates. Evaporated halide is activated by discharge. The color of light changes into
white.
NOTE:
 Brightness and the color of light may change slightly immediately after the headlamp turned ON until the xenon bulb becomes sta-
ble. This is not malfunction.
 Illumination time lag may occur between right and left. This is not
malfunction.
PRECAUTIONS FOR TROUBLE DIAGNOSIS
Representative malfunction examples are; "Light does not turn ON", "Light blinks", and "Brightness is inade-
quate." The cause often be the xenon bulb. Such malf unctions, however, are occurred occasionally by HID
control unit malfunction or lamp case malfunction. S pecify the malfunctioning part with diagnosis procedure.
WARNING:
 Never touch the harness, HID control unit, the inside and metal part of lamp when turning the head-
lamp ON or operating the lighting switch.
 Never work with wet hands.
CAUTION:
 Never perform HID control unit circuit diagnosis with a circuit tester or an equivalent.
 Temporarily install the headlamps on the vehicle. Co nnect the battery to the connector (vehicle side)
when checking ON/OFF status.
 Disconnect the battery negative terminal before di sconnecting the lamp socket connector or the har-
ness connector.
 Check for fusing of the fusible link(s), open around connector, short, disconnection if the symptom
is caused by electric error.
NOTE:
 Turn the switch OFF once before turni ng ON, if the ON/OFF is inoperative.
 The xenon bulb drops the amount of light, repeats blinking, and illuminates in red if the bulb reaches the ser-
vice life.
Steering angle sensor*1Transmits steering angle sensor signal to AFS control unit. (via CAN communication)
Combination switch
(Lighting & turn signal switch) Refer to
BCS-7, "
COMBINATION SWITCH READING SYSTEM : System Descrip-
tion".
Door switch Inputs the door switch signal to BCM.
AFS switch*
1 Inputs the AFS switch signal to AFS control unit.
 AFS switch is integrated in triple switch.
Headlamp aiming switch*
2Outputs the aiming motor drive signal to aiming motor.
Hazard switch Inputs the hazard switch signal to BCM. Part Description
JPLIA0421GB
Revision: 2010 May2011 QX56

SYSTEMEXL-15
< SYSTEM DESCRIPTION > [XENON TYPE]
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ACTIVE ADAPTIVE FRONT-LIGHTI NG SYSTEM : System DiagramINFOID:0000000006213899
ACTIVE ADAPTIVE FRONT-LIGHTING SYSTEM : System DescriptionINFOID:0000000006213900
OUTLINE
 AFS (ACTIVE ADAPTIVE FRONT-LIGHTING SY STEM) is controlled by AFS control unit.
 AFS has AFS control (swivel control) and the headlamp auto aiming control.
- AFS control swivels the headlamp to the steering direction.
- Headlamp auto aiming control moves the headlamp light axis up/down according to the vehicle height.
AFS (ADAPTIVE FRONT-LIGHTING SYSTEM)
AFS Control Description
 AFS control unit controls the headlamp (right) only when the steering wheel is turned rightward, and the
headlamp (left) only when the steering wheel is turned leftward.
 AFS control unit detects the vehicle condition nec essary for AFS control with the following signals.
- AFS switch signal
- Vehicle speed signal (received from combination meter via CAN communication)
- Steering angle sensor signal (received from steering angle sensor via CAN communication)
- Shift position signal (received from TCM via CAN communication)
- Low beam status signal (received from IPDM E/R via CAN communication)
- Engine speed signal (received from ECM via CAN communication)
 When the operation conditions are satisfied, AFS c ontrol unit controls the swivel angle depending on the
steering angle and the vehicle speed.
AFS operation condition- Swivel actuator initialization completed
- AFS “ON”(AFS OFF indicator lamp “OFF”)
- Headlamp ON
- While the engine running
- Selector lever position other than “P” or “R”
- Vehicle speed approximately 25 km/h (15.5 MPH) or more (Left swivel only; Right swivel activates regardless of the vehicle speed.)
Swivel Actuator Initialization
 AFS control unit performs the swivel actuator in itialization when detecting that the engine starts.
JMLIA1077GB
Revision: 2010 May2011 QX56

EXL-16
< SYSTEM DESCRIPTION >[XENON TYPE]
SYSTEM
- Swivels the headlamp to the vehicle-center side until it hits the stopper.
- Returns the swivel angle from the stopper. Completes t
he initialization with regarding the returned position
as the swivel angle 0 ° (straight-forward position).
Swivel Operation
 AFS control unit transmits the drive signal to the sw ivel actuator when activation conditions are satisfied.
And swivels the headlamp.
- The swivel starts after steering approximately 20 ° or more from straight-forward position.
NOTE:
The steering angle differs between right turn and left turn.
- The swivel angle becomes the maximum angle toward t he driving direction if the steering angle is approxi-
mately 90 ° or more depending on the vehicle speed. The swivel angle is maintained by shutting off the drive
signal.
- The swivel starts, and returns to the swivel angle 0 ° (straight-forward position) when the steering is returned
to the straight-forward position.
 AFS control unit returns the swivel angle to the strai ght-forward position, and stops the swivel regardless of
the steering angle if the operation condition is not satisfied while the swivel angle is 0°.
AFS OFF Indicator Lamp
 AFS control unit transmits AFS OFF indicator lamp signal to the combination meter via CAN communication.
 Combination meter turns AFS OFF indicator lamp ON /OFF/blinking according to AFS OFF indicator lamp
signal.
- AFS OFF indicator lamp is turned ON for 1 second for the AFS OFF indicator lamp bulb check when the igni-
tion switch is turned ON. AFS OFF indicator lamp is turned OFF within 1 second when the engine starts.
- AFS OFF indicator lamp turns ON when AFS is switched to “OFF” by operating AFS switch.
- AFS OFF indicator lamp blinks (1 second each) if AFS control unit detects a specific DTC.
NOTE:
Combination meter blinks AFS OFF indicator lamp (approximately 1 second each) if AFS OFF indicator
lamp signal is not received from AFS control unit.
HEADLAMP AUTO AIMING
Headlamp Auto Aiming Control Description
 AFS control unit controls the headl amp light axis height appropriately according to the vehicle height.
 AFS control unit detects the vehicle condition necessa ry for headlamp auto aiming control with the following
signals.
- Height sensor signals (front and rear)
- Vehicle speed signal (received from combination meter via CAN communication)
- Low beam status signal (received from IPDM E/R via CAN communication)
- Engine speed signal (received from ECM via CAN communication)
 When the operation conditions are satisfied, AFS cont rol unit transmits the aiming motor drive signal for
adjusting the headlamp axis height.
Headlamp auto aiming operation condition- Headlamp ON
- While the engine running
- Vehicle speed (Control mode is switched according to the driving condition.)
Headlamp Auto Aiming Operation
 AFS control unit calculates the vehicle pitch angle fr om the front and rear height sensor signal. AFS control
unit judges the angle for adjusting the axis gap from the preset position.
 AFS control unit controls the headlamp axis by c hanging the aiming motor drive signal output according to
the front and rear vehicle height when detecting the follo wing vehicle condition. Output is maintained if other
condition than following is detected.
- Engine starts.
- Headlamp is turned ON.
- Vehicle posture becomes stable after changing the v ehicle posture change is detected with the headlamp
ON and the vehicle stopped.
- Vehicle speed is maintained with the headlamp ON and the vehicle driven.
CAUTION:
Adjusted axis position may differ from the preset position although the headlamp auto aiming acti-
vates properly if the suspension is replaced or worn.
Revision: 2010 May2011 QX56

SYSTEMEXL-17
< SYSTEM DESCRIPTION > [XENON TYPE]
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ACTIVE ADAPTIVE FRONT-LIGHTING SYSTEM : Fail-SafeINFOID:0000000006422028
HEADLAMP AIMING CONTROL (MANUAL)
DTC Fail-safe AFS OFF indicator lamp Cancellation
U1000: CAN COMM CIRCUIT  Right and left swivel motors
stop at the position when DTC
is detected.
 Right and left aiming motors stop at the position when DTC
is detected. Blinks 1 second each. Ignition switch OFF
U1010: CONTROL UNIT (CAN)  Right and left swivel motors
stop at the position when DTC
is detected.
 Right and left aiming motors
stop at the position when DTC
is detected. Blinks 1 second each. Ignition switch OFF
B2503: SWIVEL ACTUATOR [RH]  Right swivel motors stop at the
position when DT C is detected.
 The signal, approximately 2 V
decreased from the levelizer
signal when DTC detected, is
output. Blinks 1 second each. Ignition switch OFF
B2504: SWIVEL ACTUATOR [LH]  Left swivel motors stop at the
position when DT C is detected.
 The signal, approximately 2 V decreased from the levelizer
signal when DTC detected, is
output. Blinks 1 second each. Ignition switch OFF
B2513: HI SEN UNUSUAL [FR]  Right and left aiming motors
stop at the position when DTC
is detected. — Ignition switch OFF
B2514: HI SEN UNUSUAL [RR]  Right and left aiming motors
stop at the position when DTC
is detected. — Ignition switch OFF
C0126: ST ANG SEN SIG  Right and left swivel motor
swivel angle returns to 0 ° and
fixed. Blinks 1 second each. Ignition switch OFF
B2516: SHIFT SIG [P, R]  Right and left swivel motor
swivel angle returns to 0 ° and
fixed. Blinks 1 second each. Ignition switch OFF
B2517: VEHICLE SPEED SIG  Right and left swivel motor
swivel angle returns to 0 ° and
fixed.
 Right and left aiming motors stop at the position when DTC
is detected. Blinks 1 second each. Ignition switch OFF
B2519: LEVELIZER CALIB  Right and left aiming motors
stop at the position when DTC
is detected. —
When the levelizer adjustment is
completed.
C0428: ST ANGLE SEN CALIB  Right and left swivel motor
swivel angle returns to 0 ° and
fixed. Blinks 1 second each.
When the steering angle sensor
neutral position registration is
competed.
B2521: ECU CIRC  Right and left swivel motors
stop at the position when DTC
is detected.
 Right and left aiming motors stop at the position when DTC
is detected. Blinks 1 second each. Ignition switch OFF
Revision: 2010 May2011 QX56