2011 INFINITI QX56 ECU

EM-64
< REMOVAL AND INSTALLATION >
TIMING CHAIN
24. Remove oil pump and oil pump drive spacer.
25. Remove front oil seal from front cover using suitable tool. Use screwdriver for removal.
CAUTION:
Be careful not to damage front cover.
26. Remove O-rings (1), (2), (3) from cylinder heads and cylinder block.
27. Remove oil filter (for valve timing control solenoid valve), if necessary.
28. Remove timing chain tensioner cover from front cover, if necessary.  Use seal cutter [SST: KV10111100 (J-37228)] to cut liquid gasket for removal.
29. Remove timing chain tensioner (bank 1) as per the following: NOTE:
To remove timing chain and related parts, start with those on bank 1. The procedure for removing parts on
bank 2 is omitted because it is the same as that for bank 1.
a. Push both sides of spring (A) against spring tension, and then press in plunger with a slack guide (2).
b. Insert a stopper pin (A) into the body hole, and then fix it with the
plunger pushed in.
30. Remove high pressure fuel pump camshaft.
31. Remove tension guide and slack guide.
32. Remove exhaust camshaft sprocket as per the following:  Secure the hexagonal portion of exhaust camshaf t using a wrench to loosen mounting bolt.
33. Remove timing chain and crankshaft sprocket. CAUTION:
After removing timing chain, never turn cranksh aft and camshaft separately, or valves will strike
the piston head.
34. Remove intake camshaft sprocket as per the following:
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1 : Timing chain tensioner (bank 1)
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Revision: 2010 May2011 QX56

TIMING CHAINEM-65
< REMOVAL AND INSTALLATION >
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 Secure the hexagonal portion (located in between journal No.1
and journal No. 2) of drive shaft (A) using a wrench (B) to
loosen mounting bolt.
NOTE:
The figure shows an example of bank 2.
CAUTION:
 Never loosen the mounting bolt by securing anyt hing other than the camshaft (drive shaft) hexago-
nal portion or with tensioning the timing chain.
 When holding the hexagonal part of camshaft (drive shaft) with a wrench, be careful not to allow the
wrench to cause interference with other parts.
 Never disassemble camshaft sprocket. [Never loosen bolts (B) as shown in the figure.]
35. Use scraper to remove all traces of old liquid gasket from front cover and opposite mating surfaces.  Remove old liquid gasket from bolt hole and thread.
INSTALLATION
: Engine front
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A: Intake
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A : Remove old liquid gasket that is stuck
B : Bolt hole
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Revision: 2010 May2011 QX56

TIMING CHAINEM-67
< REMOVAL AND INSTALLATION >
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1. Check that crankshaft key (1) and dowel pin (A) of each cam-
shaft are located as shown in the figure.
NOTE:
Though camshaft does not stop at the position as shown in the
figure, for the placement of cam nose, it is generally accepted
camshaft is placed for the same direction of the figure.
2. Install camshaft sprockets (INT and EXH).  Install onto correct side by checking with identification mark(A) on surface.
Exhaust side: Secure the hexagonal portion of exhaust camshaft using a wrench to tighten mounting bolt. Refer toEM-74, "
Exploded View".
Intake side:
 Secure the hexagonal portion (located in between journal No.1and journal No. 2) of drive shaft (A) using a wrench (B) to
tighten mounting bolt. Refer to EM-74, "
Exploded View".
NOTE:
The figure shows an example of bank 2.
3. Install high pressure fuel pump camshaft.
4. Install timing chains as per the following:
a. Install crankshaft sprockets for both banks.  Install each crankshaft sprocket so that its flange side (thelarger diameter side without teeth) (A) faces in the direction
shown in the figure.
NOTE:
The same parts are used but facing directions are different.Camshaft dowel pin
: At cylinder head upper face side in each bank
Crankshaft key : Straight up
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: Engine front
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1 : Crankshaft sprocket (bank 1 side)
2 : Crankshaft sprocket (bank 2 side)
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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)
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Revision: 2010 May2011 QX56

EX-6
< REMOVAL AND INSTALLATION >
EXHAUST SYSTEM
- Using heated oxygen sensor wrench [SST: KV10114400] (C),removal heated oxygen sensor 2.
INSTALLATION
Note the following items, and install in the reverse order of removal.
 Temporarily tighten bolts and nuts when installing exhaust pipe assembly. Tighten them to the specifiedtorque when connecting the vehicle rear to the vehicle front.
CAUTION:
 Always replace exhaust tube gasket s with new ones when reassembling.
 If heat insulator is badly deformed, repair or re place it. If deposits such as mud pile up on the heat
insulator, remove them.
 When installing heat insulator avoid large gaps or interference between heat insulator and each
exhaust pipe.
 Remove deposits from the sealing surface of each connection. Connect them securely to avoid
gases leakage.
 Check each part for unusual interference, and then tighten them to the specified torque.
 When installing each moun ting rubber, avoid twisting or unusua l extension in up/down and right/left
directions.
InspectionINFOID:0000000006289697
INSPECTION AFTER INSTALLATION
 Check clearance between tail tube and rear bumper is even.
 With engine running, check exhaust tube joints for gas leakage and unusual noises.
 Check to ensure that mounting brackets and mounting rubbers are installed properly and free from undue stress. Improper installation could result in excessive noise and vibration.
A: Bank 1
B: Bank 2
: Vehicle front
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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

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

EXL-22
< SYSTEM DESCRIPTION >[XENON TYPE]
DIAGNOSIS SYSTEM (BCM)
DIAGNOSIS SYSTEM (BCM)
COMMON ITEM
COMMON ITEM : CONSULT-III Fu
nction (BCM - COMMON ITEM)INFOID:0000000006368037
APPLICATION ITEM
CONSULT-III performs the following functions via CAN communication with BCM.
SYSTEM APPLICATION
BCM can perform the following functions for each system.
NOTE:
It can perform the diagnosis modes except the following for all sub system selection items.
×: Applicable item
*: This item is indicated, but not used.
FREEZE FRAME DATA (FFD)
The BCM records the following vehicle condition at the time a particular DTC is detected, and displays on
CONSULT-III.
Diagnosis mode Function Description
Work Support Changes the setting for each system function.
Self Diagnostic Result Displays the diagnosis results judged by BCM. Refer to BCS-57, "
DTCIndex".
CAN Diag Support Monitor Monitors the reception status of CAN communication viewed from BCM. Refer to CONSULT-III opera-
tion manual.
Data Monitor The BCM input/output signals are displayed.
Active Test The signals used to activate ea ch device are forcibly supplied from BCM.
Ecu Identification The BCM part number is displayed.
Configuration  Read and save the vehicle specification.
 Write the vehicle specification when replacing BCM.
System Sub system selection item Diagnosis mode
Work Support Data Monitor Active Test
Door lock DOOR LOCK ×××
Rear window defogger REAR DEFOGGER ××
Warning chime BUZZER ××
Interior room lamp timer INT LAMP ×××
Exterior lamp HEAD LAMP ×××
Wiper and washer WIPER ×××
Turn signal and hazard warning lamps FLASHER ×××
— AIR CONDITONER* ××
 Intelligent Key system
 Engine start system INTELLIGENT KEY
×××
Combination switch COMB SW ×
Body control system BCM ×
IVIS IMMU ×××
Interior room lamp battery saver BATTERY SAVER ×××
Back door TRUNK ×
Vehicle security system THEFT ALM ×××
RAP system RETAINED PWR ×
Signal buffer system SIGNAL BUFFER ××
Revision: 2010 May2011 QX56