2011 INFINITI QX56 Engine mechanical

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QUICK REFERENCE INDEX
AGENERAL INFORMATIONGIGeneral Information
BENGINEEMEngine Mechanical
LUEngine Lubrication System
COEngine Cooling System
ECEngine Control System
FLFuel System
EXExhaust System
STRStarting System
ACCAccelerator Control System
CHYBRIDHBCHybrid Control System
HBBHybrid Battery System
HBRHybrid Brake System
DTRANSMISSION & DRIVE-
LINECLClutch
TMTransaxle & Transmission
DLNDriveline
FAXFront Axle
RAXRear Axle
ESUSPENSIONFSUFront Suspension
RSURear Suspension
SCSSuspension Control System
WTRoad Wheels & Tires
FBRAKESBRBrake System
PBParking Brake System
BRCBrake Control System
GSTEERINGSTSteering System
STCSteering Control System
HRESTRAINTSSBSeat Belt
SBCSeat Belt Control System
SRSRS Airbag
SRCSRS Airbag Control System
IVENTILATION, HEATER &
AIR CONDITIONERVTLVentilation System
HAHeater & Air Conditioning System
HACHeater & Air Conditioning Control System
JBODY INTERIORINTInterior
IPInstrument Panel
SESeat
ADPAutomatic Drive Positioner
KBODY EXTERIOR,
DOORS, ROOF & VEHICLE
SECURITYDLKDoor & Lock
SECSecurity Control System
GWGlass & Window System
PWCPower Window Control System
RFRoof
HDHood
EXTExterior
BRMBody Repair
LDRIVER CONTROLSMIRMirrors
EXLExterior Lighting System
INLInterior Lighting System
WWWiper & Washer
DEFDefogger
HRNHorn
MELECTRICAL & POWER
CONTROLPWOPower Outlet
BCSBody Control System
LANLAN System
PCSPower Control System
CHGCharging System
PGPower Supply, Ground & Circuit Elements
NDRIVER INFORMATION &
MULTIMEDIAMWIMeter, Warning Lamp & Indicator
WCSWarning Chime System
SNSonar System
AVAudio, Visual & Navigation System
OCRUISE CONTROL &
DRIVER ASSISTANCECCSCruise Control System
DASDriver Assistance System
DMSDrive Mode System
PMAINTENANCEMAMaintenance
All rights reserved. No part
of this Service Manual may
be reproduced or stored in a
retrieval system, or transmit-
ted in any form, or by any
means, electronic, mechani-
cal, recording or otherwise,
without the prior written per-
mission of NISSAN MOTOR
CO., LTD.
Edition: May 2010
Publication No. SM1E-1Z62U0

HEAVY TIGHT-CORNER BRAKING SYMPTOM OCCURS
DLN-99
< SYMPTOM DIAGNOSIS > [TRANSFER: ATX90A]
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SYMPTOM DIAGNOSIS
HEAVY TIGHT-CORNER BRAKING SYMPTOM OCCURS
DescriptionINFOID:0000000006222312
Heavy tight-corner braking symptom o ccurs when the vehicle is driven and the steering wheel is turned fully to
either side after the engine is started.
NOTE:
Light tight-corner braking symptom may occur dependi ng on driving conditions. This is not malfunction.
Diagnosis ProcedureINFOID:0000000006222313
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ECM”.
Is any DTC detected?
YES >> Check the DTC. Refer to EC-98, "DTC Index".
NO >> GO TO 2.
2.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is any DTC detected?
YES >> Check the DTC. Refer to DLN-29, "DTC Index".
NO >> GO TO 3.
3.CHECK TRANSFER INTERNAL FUNCTION
With CONSULT-III
1. Remove transfer control actuator. Refer to DLN-114, "
Removal and Installation".
2. Turn the actuator shaft. Refer to DLN-114, "
Inspection".
3. Check “ROTARY POSI SEN” of CONSULT-II I “DATA MONITOR” for “ALL MODE AWD/4WD”.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Transfer assembly is mechanical malfunction. Replace transfer assembly. Refer to DLN-121,
"Removal and Installation".
Monitor item Condition Status
ROTARY POSI SEN Turn the actuator shaft. Value is changing
Revision: 2010 May2011 QX56

BASIC INSPECTIONEC-139
< BASIC INSPECTION > [VK56VD]
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BASIC INSPECTION
Work ProcedureINFOID:0000000006217739
1.INSPECTION START
1. Check service records for any recent repairs that ma y 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 leakage
- Air cleaner clogging
- Gasket
3. Check 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 to the middle of gauge.
Check that engine stays below 1,000 rpm.
5. Run engine at approximately 2,000 rpm for approximately 2 min- utes under no load.
6. Check that no DTC is displayed with CONSULT-III or GST.
Are any DTCs detected?
YES >> GO TO 2.
NO >> GO TO 3.
2.REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnosis Procedure.
>> GO TO 3
3.CHECK IDLE SPEED
1. Run engine at approximately 2,000 rpm for approximately 2 minutes under no load.
SEF983U
SEF976U
SEF977U
Revision: 2010 May2011 QX56

EC-526
< SYMPTOM DIAGNOSIS >[VK56VD]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Manifold absolute pressure sensor circuit 3
EC-210
Battery current sensor 4 5 5 3EC-412EC-420
EC-424
Heated oxygen sensor 2 6 6 6 6 5EC-243EC-249
EC-257
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank 5
5 FL-4
Fuel piping 555 55 5
FL-4
Vapor lock —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gasoline,
Low octane) —
Revision: 2010 May2011 QX56

EM-1
ENGINE
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SECTION EM
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CONTENTS
ENGINE MECHANICAL
PRECAUTION ................ ...............................3
PRECAUTIONS .............................................. .....3
Precaution for Procedure without Cowl Top Cover ......3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
3
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
3
Precaution for Drain Engine Coolant and Engine
Oil ..............................................................................
4
Precaution for Disconnecting Fuel Piping .................4
Precaution for Handling High Pressure Fuel Sys-
tem ............................................................................
4
Precaution for Removal and Disassembly ................4
Precaution for Inspection, Repair and Replace-
ment ..........................................................................
4
Precaution for Assembly and Installation ..................4
Parts Requiring Angle Tightening .............................5
Precaution for Liquid Gasket .....................................5
Definitions of Bank Names ........................................6
PREPARATION ............................................7
PREPARATION .............................................. .....7
Special Service Tool ........................................... ......7
Commercial Service Tool ..........................................9
BASIC INSPECTION ...................................12
CAMSHAFT VALVE CLEARANCE ............... ....12
Inspection ............................................................ ....12
COMPRESSION PRESSURE ............................16
Inspection ............................................................ ....16
SYMPTOM DIAGNOSIS ..............................18
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ ....
18
NVH Troubleshooting - Engine Noise .............. ....18
Use the Chart Below to Help You Find the C
ause of the Symptom ........................................ ....
19
PERIODIC MAINTENANCE ........................20
DRIVE BELTS ...................................................20
Exploded View ..................................................... ....20
Checking ..................................................................20
Tension Adjustment ................................................20
Removal and Installation .........................................20
Inspection ................................................................21
AIR CLEANER FILTER .....................................22
Exploded View .........................................................22
Removal and Installation .........................................22
SPARK PLUG ...................................................23
Exploded View .........................................................23
Removal and Installation .........................................23
Inspection ................................................................24
REMOVAL AND INSTALLATION ...............25
ENGINE COVER ...............................................25
Exploded View ..................................................... ....25
Removal and Installation .........................................25
DRIVE BELT AUTO TENSIONER AND IDLER
PULLEY .............................................................
26
Exploded View .........................................................26
Removal and Installation .........................................26
AIR CLEANER AND AIR DUCT .......................27
Exploded View .........................................................27
Removal and Installation .........................................27
Inspection ................................................................28
IGNITION COIL .................................................29
Exploded View .........................................................29
Removal and Installation .........................................29
INTAKE MANIFOLD .........................................30
Exploded View .........................................................30
Revision: 2010 May2011 QX56

GI-36
< BASIC INSPECTION >
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
BASIC INSPECTION
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
Work FlowINFOID:0000000006280851
WORK FLOW
Control Units and Electrical PartsINFOID:0000000006280852
PRECAUTIONS
 Never reverse polarity of battery terminals.
 Install only parts specified for a vehicle.
 Before replacing the control unit, check the i nput and output and functions of the component parts.
 Do not apply excessive force when disconnecting a connector.
SGI838
STEP DESCRIPTION
STEP 1 Get detailed information about the conditions and the environment when the incident occurred.
The following are key pieces of information required to make a good analysis:
WHAT
Vehicle Model, Engine, Transmission/Transaxle and the System (i.e. Radio).
WHEN Date, Time of Day, Weather Conditions, Frequency.
WHERE Road Conditions, Altitude and Traffic Situation.
HOW System Symptoms, Operating Conditions
(Other Components Interaction).
Service History and if any After Market Accessories have been installed.
STEP 2 Operate the system, road test if necessary.
Verify the parameter of the incident.
If the problem cannot be duplicated, refer to “Incident Simulation Tests”.
STEP 3 Get the proper diagnosis materials together including:
 Power Supply Routing
 System Operation Descriptions
 Applicable Service Manual Sections
 Check for any Service Bulletins
Identify where to begin diagnosis based upon your knowledge of the system operation and the customer comments.
STEP 4 Inspect the system for mechanical binding, loose connectors or wiring damage.
Determine which circuits and components are involved and diagnose using the Power Supply Routing and Harness Lay-
outs.
STEP 5 Repair or replace the incident circuit or component.
STEP 6 Operate the system in all modes. Verify the system works properly under all conditions. check you have not inadvertently
created a new incident during your diagnosis or repair steps.
Revision: 2010 May2011 QX56

PCS
SYSTEMPCS-37
< SYSTEM DESCRIPTION > [POWER DISTRIBUTION SYSTEM]
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SYSTEM
POWER DISTRIBUTION SYSTEM
POWER DISTRIBUTION SYSTEM : System DiagramINFOID:0000000006220196
POWER DISTRIBUTION SYST
EM : System DescriptionINFOID:0000000006220197
SYSTEM DESCRIPTION
 PDS (POWER DISTRIBUTION SYSTEM) is the system that BCM controls with the operation of the push-
button ignition switch and performs the power distributi on to each power circuit. This system is used instead
of the mechanical power supply changing mechanism wit h the operation of the conventional key cylinder.
 The push-button ignition switch can be operated when Intelligent Key is in the following condition. Refer to Engine Start Function for details.
- Intelligent Key is in the detection area of the inside key antenna.
- Intelligent Key backside is contact ed to push-button ignition switch.
 The push-button ignition switch operation is input to BCM as a signal. BCM changes the power supply posi-
tion according to the status and operates the follo wing relays to supply power to each power circuit.
- Ignition relay (inside IPDM E/R)
- Ignition relay-1
- ACC relay
- Blower relay
NOTE:
The engine switch operation changes due to the conditions of brake pedal, selector lever and vehicle speed.
 The power supply position can be confirmed with the light ing of the indicators near the push-button ignition
switch.
BATTERY SAVER SYSTEM
When all the following conditions are met for 60 minutes, the battery saver system will cut off the power supply
to prevent battery discharge.
 The ignition switch is in the ACC position
 All doors are closed
 Selector lever is in the P position
Reset Condition of Battery Saver System
In order to prevent the battery from discharging, the battery saver system will cut off the power supply when all
doors are closed, the selector lever is on P position and t he ignition switch is left on ACC position for 1 hour. If
any of the following conditions are met the battery saver system is released and the steering will change auto-
matically to lock position from OFF position.
 Opening any door
 Operating with door request switch on door lock
 Operating with Intelligent Key on door lock
Press push-button ignition switch and ignition swit ch will change to ACC position from OFF position.
JMMIA0444GB
Revision: 2010 May2011 QX56

SYSTEMSEC-13
< SYSTEM DESCRIPTION > [WITH INTELLIGENT KEY SYSTEM]
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 Up to 4 Intelligent Keys can be registered (Includi ng the standard Intelligent Key) upon request from the cus-
tomer.
NOTE:
Refer to DLK-18, "
INTELLIGENT KEY SYSTEM : System Description" for any functions other than engine
start function of Intelligent Key system.
PRECAUTIONS FOR INTELLIGENT KEY SYSTEM
The transponder [the chip for IVIS (NATS) ID verification] is integrated into the Intelligent Key. (For the
conventional models, it is integrated into the mech anical key.) Therefore, ID verification cannot be per-
formed by mechanical key only.
In that case, the IVIS (NATS) ID verification can be performed when Intelligent Key backside is con-
tacted to push-button ignition switch. If verification result is OK, engine can be started.
OPERATION WHEN INTELLIGENT KEY IS CARRIED
1. When the push-button ignition switch is pressed, the BCM activates the inside key antenna and transmits
the request signal to the Intelligent Key.
2. The Intelligent Key receives the request signal and transmits the Intelligent Key ID signal to the BCM.
3. BCM receives the Intelligent Key ID signal via remote keyless entry receiver and verifies it with the regis-
tered ID.
4. BCM transmits the unlock signal to steering lock unit and IPDM E/R if the verification results are OK.
5. IPDM E/R turns the steering lock relay ON and supplies power supply to the steering lock unit.
6. The steering lock releases.
7. BCM transmits the power supply stop signal to IPDM E/R when detecting that the steering lock is in the
unlock condition.
8. IPDM E/R turns the steering lock relay OFF and stops power supply to the steering lock unit.
9. BCM turns ACC relay ON and transmits the ignition power supply ON signal to IPDM E/R.
10. IPDM E/R turns the ignition relay ON and starts the ignition power supply.
11. BCM detects that the selector lever position and brake pedal operating condition.
12. BCM transmits the starter request signal to IPDM E/R and turns the starter relay in IPDM E/R ON if BCM
judges that the engine start condition* is satisfied.
13. IPDM E/R turns the starter control relay ON when receiving the starter request signal.
14. Power supply is supplied through the starter relay and the starter control relay to operate the starter motor. CAUTION:
If a malfunction is detected in the Intelligent Key system, the “KEY” warning lamp in the combina-
tion meter illuminates. At that time, the engine cannot be started.
15. When BCM receives feedback signal from ECM indicati ng that the engine is started, the BCM transmits a
stop signal to IPDM E/R and stops cranking by turning OFF the starter motor relay. (If engine start is
unsuccessful, cranking stops automatically within 5 seconds.)
CAUTION:
When the Intelligent Key is carried outside of th e vehicle (inside key antenna detection area) while
the power supply is in the ACC or ON position, even if the engine start condition* is satisfied, the
engine cannot be started.
*: For the engine start condition, refer to “POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON
IGNITION SWITCH OPERATION”.
OPERATION RANGE
Engine can be started when Intelligent Key is inside the vehicle. However, sometimes engine may not start
when Intelligent Key is on instrument panel or in glove box.
ENGINE START OPERATION WHEN INTELLIGENT KEY IS CONTACTED TO PUSH-BUTTON IG-
NITION SWITCH
When Intelligent Key battery is discharged, the IVIS (NATS) ID verification between transponder in Intelligent
Key and BCM is performed when Intelligent Key backside is contacted to push-button ignition switch. If the
verification result is OK, engine can be started.
STEERING LOCK OPERATION
Steering is locked by steering lock unit when any of the following conditions are met.
Revision: 2010 May2011 QX56