2011 INFINITI QX56 belt

EC-24
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
Electric throttle control actuator consists of throttle bod
y, throttle valve, throttle control motor and throttle posi-
tion sensor.
THROTTLE CONTROL MOTOR
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor. The throttle position
sensor provides feedback to the ECM, when opens/closes the throttle valve in response to driving conditions
via the throttle control motor.
THROTTLE POSITION SENSOR
The throttle position (TP) sensor responds to the throttle valve move-
ment.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometer which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and controls the throttle valve opening angle in response to
driving conditions via the throttle control motor.
Electrically-controlled cooling fan couplingINFOID:0000000006217668
Electrically-controlled cooling fan coupling is integrat ed with a fan coupling, fan coupling driver, and fan speed
sensor, mounted to the fan pulley, and actuated by the dr ive belt to rotate the cooling fan at a speed suitable
for a driving condition.
JSBIA0270GB
PBIB0145E
JSBIA0289ZZ
Revision: 2010 May2011 QX56

EC-166
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of power steering, alternat
or, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 27.
16.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
Is the inspection result normal?
YES >> GO TO 18.
NO >> Repair or replace malfunctioning part, and then GO TO 17.
17.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2” AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2” and “B/FUE L SCHDL” in “SPEC” of “DATA MONITOR” mode, and
check that each indication is within the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> “B/FUEL SCHDL” is more, “A/F ALPHA-B1” and “A /F ALPHA-B2” are less than the SP value: GO
TO 18.
18.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and then reconnect it again.
>> GO TO 19.
19.CHECK “A/F ALPHA-B1” AND “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1” and “A/F ALPHA-B2” in “ SPEC” of “DATA MONITOR” mode, and check that each
indication is within the SP value.
Is the measurement value within the SP value?
YES >> Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-201, "Diagno-
sis Procedure". Then GO TO 26.
NO >> GO TO 20.
20.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and check that the indication is within the SP
value.
Is the measurement value within the SP value?
YES >> GO TO 21.
NO >> More than the SP value: Replace malfuncti oning mass air flow sensor, and then GO TO 26.
21.REPLACE ECM
1. Replace ECM.
2. Perform EC-143, "
Work Procedure".
Revision: 2010 May2011 QX56

ELECTRICALLY-CONTROLLED COOLING FAN COUPLINGEC-495
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
Component Function CheckINFOID:0000000006217997
1.CHECK COOLING FAN FUNCTION
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage.
NOTE:
Speed changes gradually as the percentage changes.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98°C (209 °F).
2. Check that cooling fan speed increase.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-495, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217998
1.CHECK DRIVE BELT
1. Turn ignition switch OFF.
2. Check that the drive belt is not broken.
Is inspection result normal?
YES >> GO TO 2.
NO >> Replace drive belt.
2.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING POWER SUPPLY
1. Disconnect electrically-controlled c ooling fan coupling harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for power supply circuit.
3.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between electrically-cont rolled cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL SIGNAL
WITH CONSULT-III
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector TerminalF39 1 Ground Battery voltage
+ −Continuity
Electrically-controlled cooling fan coupling
Connector TerminalF39 6 Ground Existed
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

EM-2
Removal and Installation ........................................30
ROCKER COVER ..............................................33
Exploded View ..................................................... ...33
Removal and Installation ........................................33
VVEL ACTUATOR ASSEMBLY ........................36
Exploded View ..................................................... ...36
Removal and Installation ........................................36
Inspection ...............................................................39
EXHAUST MANIFOLD AND THREE WAY
CATALYST ........................................................
40
Exploded View ..................................................... ...40
Removal and Installation ........................................40
Inspection ...............................................................42
HIGH PRESSURE FUEL PUMP AND FUEL
HOSE .................................................................
43
Exploded View ..................................................... ...43
Removal and Installation ........................................43
Inspection ...............................................................46
FUEL INJECTOR AND FUEL TUBE .................48
Exploded View ..................................................... ...48
Removal and Installation ........................................49
Inspection ...............................................................53
OIL PAN (LOWER) AND OIL STRAINER .........54
Exploded View ..................................................... ...54
Removal and Installation ........................................55
Inspection ...............................................................56
OIL PAN (UPPER) .......................................... ...57
Exploded View ..................................................... ...57
Removal and Installation ........................................58
Inspection ...............................................................60
TIMING CHAIN ............................................... ...61
Exploded View ..................................................... ...61
Removal and Installation ........................................62
Inspection ...............................................................72
CAMSHAFT .......................................................74
Exploded View ..................................................... ...74
Removal and Installation ........................................75
Inspection ...............................................................77
CYLINDER HEAD ..............................................86
Exploded View ..................................................... ...86
Removal and Installation ........................................87
Disassembly and Assembly ....................................89
Inspection ............................................................. ...92
OIL SEAL ...........................................................96
FRONT OIL SEAL .................................................. ...96
FRONT OIL SEAL : Removal and Installation ........96
REAR OIL SEAL .................................................... ...96
REAR OIL SEAL : Removal and Installation ...........97
UNIT REMOVAL AND INSTALLATION ....98
ENGINE ASSEMBL Y ..................................... ...98
Exploded View ..................................................... ...98
Removal and Installation .........................................99
Inspection ..............................................................102
UNIT DISASSEMBLY AND ASSEMBLY ..103
ENGINE STAND SETTING ..............................103
Setting .................................................................. .103
ENGINE UNIT ...................................................105
Disassembly ......................................................... .105
Assembly ..............................................................105
CYLINDER BLOCK ..........................................106
Exploded View ..................................................... .106
Disassembly and Assembly ..................................107
Inspection ..............................................................115
HOW TO SELECT PISTON AND BEARING ...125
Description ........................................................... .125
Piston ....................................................................125
Connecting Rod Bearing .....................................126
Main Bearing ........................................................128
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
132
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
132
General Specification .......................................... .132
Drive Belts .............................................................132
Spark Plug ............................................................132
Exhaust Manifold ..................................................133
Camshaft ...............................................................133
Cylinder Head ......................................................135
Cylinder Block ......................................................137
Main Bearing ........................................................141
Connecting Rod Bearing .....................................142
Revision: 2010 May2011 QX56

PRECAUTIONSEM-3
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Procedur
e without Cowl Top CoverINFOID:0000000006289506
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006417202
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:0000000006289508
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.
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Revision: 2010 May2011 QX56

NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGEM-19
< SYMPTOM DIAGNOSIS >
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Use the Chart Below to Help You Find the Cause of the SymptomINFOID:0000000006289523
1. Locate the area where noise occurs.
2. Confirm the type of noise.
3. Specify the operating condition of the engine.
4. Check specified noise source.
If necessary, repair or replace these parts.
A: Closely related B: Related C: Sometimes related —: Not related Location
of noise Type of
noise Operating condition of engine
Source of noise Check item Refer-
ence page
Before
warm- up After
warm- up When
start- ing When
idling When
racing While
driving
Top of en-
gine
Rocker
cover
Cylinder
head Ticking or
clicking
CA—AB— Tappet
noiseValve clearance
EM-12
Rattle C A — A B C Camshaft
bearing
noiseCamshaft runout
Camshaft journal oil
clearance
EM-77
Crank-
shaft pul-
ley
Cylinder
block
(Side of
engine)
Oil panSlap or
knock
—A—B B—
Piston pin
noisePiston to piston pin oil
clearance
Connecting rod bushing
oil clearance
EM-115
Slap or
rap
A——B B A
Piston
slap noisePiston to cylinder bore
clearance
Piston ring side clear-
ance
Piston ring end gap
Connecting rod bend
and torsion
EM-115
Knock A B C B B B
Connect-
ing rod
bearing
noiseConnecting rod bushing
oil clearance
Connecting rod bearing
oil clearance
EM-115
Knock A B — A B C
Main bear-
ing noiseMain bearing oil clear-
ance
Crankshaft runout
EM-115
Front of
engine
Timing
chain caseTapping or
ticking
AA—BBB Timing
chain and
timing
chain ten-
sioner
noiseTiming chain cracks
and wears
Timing chain tensioner
operation
EM-72
Front of
engineSqueak-
ing or fizz-
ing
AB—B—C Drive belts
(Sticking
or slip-
ping)Drive belts deflection
EM-20
CreakingABABAB Drive belts
(Slipping)Idler pulley bearing op-
eration
Squall
Creak AB—BAB Water
pump
noiseWater pump operation
CO-19
Revision: 2010 May2011 QX56

EM-20
< PERIODIC MAINTENANCE >
DRIVE BELTS
PERIODIC MAINTENANCE
DRIVE BELTS
Exploded ViewINFOID:0000000006289524
CheckingINFOID:0000000006289525
WARNING:
Be sure to perform the these steps when engine is stopped.
 Check that the indicator (C) (notch on fixed side) of each auto-tensioner is within the possible use range (A).
NOTE:
 Check the each auto-tensioners indication when the engine is cold.
 When new drive belts is installed, the indicator (notch on fixed side) should be within the range (B) in the\
figure.
 Visually check all drive belts for wear, damage or cracks.
 If the indicator (notch on fixed side) is out of the possible use range or drive belts are damaged, replace drive
belts.
Tension AdjustmentINFOID:0000000006289526
Refer to EM-132, "Drive Belts".
Removal and InstallationINFOID:0000000006289527
REMOVAL
1. Move reservoir tank to the position without the hindrance for work. Refer to CO-13, "Exploded View".
1. Drive belt 2. Power steering oil pump pulley 3. Alternator pulley
4. Crankshaft pulley 5. A/C compressor 6. Idler pulley
7. Cooling fan pulley 8. Water pump pulley 9. Drive belt auto-tensioner
A. Possible use range B. Range when new drive belt is in-
stalledC. Indicator
D. View D
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Revision: 2010 May2011 QX56