2007 INFINITI QX56 engine

SE-4
< SERVICE INFORMATION >
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000003533151
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000003533152
Tool number
(Kent-Moore No.)
Tool nameDescription
—
(J-39570)
Chassis earLocating the noise
—
(J-43980)
NISSAN Squeak and Rattle
KitRepairing the cause of noise
SIIA0993E
SIIA0994E
(Kent-Moore No.)
Tool nameDescription
(J-39565)
Engine earLocating the noise
SIIA0995E

SE-6
< SERVICE INFORMATION >
SQUEAK AND RATTLE TROUBLE DIAGNOSIS
If the noise can be duplicated easily during the test drive, to help identify the source of the noise, try to dupli-
cate the noise with the vehicle stopped by doing one or all of the following:
1) Close a door.
2) Tap or push/pull around the area where the noise appears to be coming from.
3) Rev the engine.
4) Use a floor jack to recreate vehicle “twist”.
5) At idle, apply engine load (electrical load, half-clutch on M/T model, drive position on A/T model).
6) Raise the vehicle on a hoist and hit a tire with a rubber hammer.
• Drive the vehicle and attempt to duplicate the conditions the customer states exist when the noise occurs.
• If it is difficult to duplicate the noise, drive the vehicle slowly on an undulating or rough road to stress the
vehicle body.
CHECK RELATED SERVICE BULLETINS
After verifying the customer concern or symptom, check ASIST for Technical Service Bulletins (TSBs) related
to that concern or symptom.
If a TSB relates to the symptom, follow the procedure to repair the noise.
LOCATE THE NOISE AND IDENTIFY THE ROOT CAUSE
1. Narrow down the noise to a general area.To help pinpoint the source of the noise, use a listening tool
(Chassis Ear: J-39570, Engine Ear: J-39565 and mechanic's stethoscope).
2. Narrow down the noise to a more specific area and identify the cause of the noise by:
• removing the components in the area that you suspect the noise is coming from.
Do not use too much force when removing clips and fasteners, otherwise clips and fasteners can be broken
or lost during the repair, resulting in the creation of new noise.
• tapping or pushing/pulling the component that you suspect is causing the noise.
Do not tap or push/pull the component with excessive force, otherwise the noise will be eliminated only tem-
porarily.
• feeling for a vibration with your hand by touching the component(s) that you suspect is (are) causing the
noise.
• placing a piece of paper between components that you suspect are causing the noise.
• looking for loose components and contact marks.
Refer to SE-7, "
Generic Squeak and Rattle Troubleshooting" .
REPAIR THE CAUSE
• If the cause is a loose component, tighten the component securely.
• If the cause is insufficient clearance between components:
- separate components by repositioning or loosening and retightening the component, if possible.
- insulate components with a suitable insulator such as urethane pads, foam blocks, felt cloth tape or urethane
tape. A NISSAN Squeak and Rattle Kit (J-43980) is available through your authorized NISSAN Parts Depart-
ment.
CAUTION:
Do not use excessive force as many components are constructed of plastic and may be damaged.
Always check with the Parts Department for the latest parts information.
The following materials are contained in the NISSAN Squeak and Rattle Kit (J-43980). Each item can be
ordered separately as needed.
URETHANE PADS [1.5 mm (0.059 in) thick]
Insulates connectors, harness, etc.
76268-9E005: 100×135 mm (3.94×5.31 in)/76884-71L01: 60×85 mm (2.36×3.35 in)/76884-71L02: 15×25
mm (0.59×0.98 in)
INSULATOR (Foam blocks)
Insulates components from contact. Can be used to fill space behind a panel.
73982-9E000: 45 mm (1.77 in) thick, 50×50 mm (1.97×1.97 in)/73982-50Y00: 10 mm (0.39 in) thick,
50×50 mm (1.97×1.97 in)
INSULATOR (Light foam block)
80845-71L00: 30 mm (1.18 in) thick, 30×50 mm (1.18×1.97 in)
FELT CLOTH TAPE
Used to insulate where movement does not occur. Ideal for instrument panel applications.
68370-4B000: 15×25 mm (0.59×0.98 in) pad/68239-13E00: 5 mm (0.20 in) wide tape roll. The following
materials not found in the kit can also be used to repair squeaks and rattles.
UHMW (TEFLON) TAPE
Insulates where slight movement is present. Ideal for instrument panel applications.

SE-8
< SERVICE INFORMATION >
SQUEAK AND RATTLE TROUBLE DIAGNOSIS
Most of these incidents can be repaired by adjusting, securing or insulating the item(s) or component(s) caus-
ing the noise.
SUNROOF/HEADLINING
Noises in the sunroof/headlining area can often be traced to one of the following:
1. Sunroof lid, rail, linkage or seals making a rattle or light knocking noise
2. Sun visor shaft shaking in the holder
3. Front or rear windshield touching headliner and squeaking
Again, pressing on the components to stop the noise while duplicating the conditions can isolate most of these
incidents. Repairs usually consist of insulating with felt cloth tape.
OVERHEAD CONSOLE (FRONT AND REAR)
Overhead console noises are often caused by the console panel clips not being engaged correctly. Most of
these incidents are repaired by pushing up on the console at the clip locations until the clips engage.
In addition look for:
1. Loose harness or harness connectors.
2. Front console map/reading lamp lense loose.
3. Loose screws at console attachment points.
SEATS
When isolating seat noise it's important to note the position the seat is in and the load placed on the seat when
the noise is present. These conditions should be duplicated when verifying and isolating the cause of the
noise.
Cause of seat noise include:
1. Headrest rods and holder
2. A squeak between the seat pad cushion and frame
3. The rear seatback lock and bracket
These noises can be isolated by moving or pressing on the suspected components while duplicating the con-
ditions under which the noise occurs. Most of these incidents can be repaired by repositioning the component
or applying urethane tape to the contact area.
UNDERHOOD
Some interior noise may be caused by components under the hood or on the engine wall. The noise is then
transmitted into the passenger compartment.
Causes of transmitted underhood noise include:
1. Any component mounted to the engine wall
2. Components that pass through the engine wall
3. Engine wall mounts and connectors
4. Loose radiator mounting pins
5. Hood bumpers out of adjustment
6. Hood striker out of adjustment
These noises can be difficult to isolate since they cannot be reached from the interior of the vehicle. The best
method is to secure, move or insulate one component at a time and test drive the vehicle. Also, engine RPM
or load can be changed to isolate the noise. Repairs can usually be made by moving, adjusting, securing, or
insulating the component causing the noise.

TF-1
DRIVELINE/AXLE
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SECTION TF
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CONTENTS
TRANSFER
SERVICE INFORMATION ............................3
PRECAUTIONS ...................................................3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
3
Precaution for Transfer Assembly and Transfer
Control Unit Replacement .........................................
3
Precaution .................................................................4
Service Notice ...........................................................4
PREPARATION ...................................................6
Special Service Tool .................................................6
Commercial Service Tool ..........................................9
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ............................
10
NVH Troubleshooting Chart ....................................10
TRANSFER FLUID .............................................11
Replacement ...........................................................11
Inspection ................................................................11
ALL-MODE 4WD SYSTEM ................................12
Cross-Sectional View ..............................................12
Power Transfer ........................................................12
System Description .................................................14
Schematic ...............................................................19
CAN Communication ...............................................20
TROUBLE DIAGNOSIS .....................................21
How to Perform Trouble Diagnosis .........................21
Location of Electrical Parts ......................................22
Circuit Diagram .......................................................23
Wiring Diagram - T/F - .............................................24
Inspections Before Trouble Diagnosis ....................31
Trouble Diagnosis Chart by Symptom ....................34
Transfer Control Unit Input/Output Signal Refer-
ence Value ..............................................................
35
CONSULT-II Function (ALL MODE AWD/4WD) .....42
Self-Diagnosis Procedure .......................................48
TROUBLE DIAGNOSIS FOR SYSTEM ............51
Power Supply Circuit for Transfer Control Unit ........51
Transfer Control Unit ...............................................53
Output Shaft Revolution Signal (TCM) ....................53
Vehicle Speed Sensor (ABS) ..................................54
Neutral-4LO Switch .................................................54
4WD Shift Switch .....................................................57
Wait Detection Switch ..............................................60
PNP Switch Signal (TCM) .......................................63
Actuator Motor .........................................................64
Actuator Position Switch ..........................................69
Transfer Control Device ...........................................72
Engine Speed Signal (ECM) ....................................76
Clutch Pressure Solenoid ........................................76
2-4WD Solenoid ......................................................80
Transfer Motor .........................................................84
Transfer Fluid Temperature .....................................90
Clutch Pressure Switch ...........................................92
Line Pressure Switch ...............................................94
Throttle Position Signal (ECM) ................................97
ABS Operation Signal (ABS) ...................................97
VDC Operation Signal (ABS) ...................................98
TCS Operation Signal (ABS) ...................................98
CAN Communication Line .......................................99
ATP Switch ..............................................................99
TROUBLE DIAGNOSIS FOR SYMPTOMS ....102
4WD Shift Indicator Lamp and 4LO Indicator
Lamp Do Not Turn ON ...........................................
102
4WD Warning Lamp Does Not Turn ON ...............104
4WD Shift Indicator Lamp or 4LO Indicator Lamp
Does Not Change ..................................................
107
ATP Warning Lamp Turns ON ...............................109
4LO Indicator Lamp Repeats Flashing ..................110
4WD Warning Lamp Flashes Rapidly ....................111
4WD Warning Lamp Flashes Slowly .....................112
Heavy Tight-corner Braking Symptom Occurs ......113
4WD System Does Not Operate ............................114
TRANSFER CONTROL UNIT .........................115
Removal and Installation .......................................115

PRECAUTIONS
TF-3
< SERVICE INFORMATION >
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SERVICE INFORMATION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000003532506
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal
injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.
Precaution for Transfer Assembly and Transfer Control Unit ReplacementINFOID:0000000003532507
When replacing transfer assembly or transfer control unit, check the 4WD shift indicator lamp as follows.
1. Turn ignition switch “ON”.
2. Check 4WD shift indicator lamp is turned ON for approx. 1 second.
• If OK, the position between transfer assembly and transfer control unit is correct.
• If NG, the position is different between transfer assembly and transfer control unit.
Adjust the position between transfer assembly and transfer control unit. Refer to "METHOD FOR POSITION
ADJUSTMENT".
METHOD FOR POSITION ADJUSTMENT
1. Start engine. Run the engine for at least 10 seconds.
2. Stop vehicle and move A/T selector lever to “N” position with brake pedal depressed. Stay in "N" for at
least 2 seconds.
3. Turn 4WD shift switch to “2WD” position. Stay in "2WD" for at least 2 seconds.
4. Turn ignition switch “OFF”.
5. Start engine.
6. Erase self-diagnosis. Refer to TF-42, "
CONSULT-II Function (ALL MODE AWD/4WD)" (with CONSULT-II)
or TF-48, "
Self-Diagnosis Procedure" (without CONSULT-II).
7. Check 4WD shift indicator lamp. Refer to TF-31, "
Inspections Before Trouble Diagnosis".
If 4WD shift indicator lamp does not indicate "2WD", install new transfer control unit and retry the above
check.

TRANSFER FLUID
TF-11
< SERVICE INFORMATION >
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TRANSFER FLUID
ReplacementINFOID:0000000003532513
DRAINING
1. Stop the engine.
2. Remove the drain plug and gasket to drain the transfer fluid as
shown.
3. Install the new gasket on the drain plug and install the drain plug
in the transfer. Tighten the drain plug to specification.
CAUTION:
Do not reuse the gasket.
FILLING
1. Remove the filler plug and gasket.
2. Fill with new specified fluid until the fluid level reaches the spec-
ified limit near the filler plug hole as shown.
CAUTION:
Carefully fill the transfer with fluid. Filling should take
approximately three minutes.
3. Leave the vehicle for three minutes and then check the fluid
level again as shown.
4. Install the new gasket on the filler plug and install the filler plug in the transfer. Tighten the filler plug to
specification.
CAUTION:
Do not reuse the gasket.
InspectionINFOID:0000000003532514
FLUID LEAKAGE AND FLUID LEVEL
1. Check for any fluid leaks from the transfer assembly or around it and correct as necessary.
2. Remove the filler plug to check the fluid level at the filler plug
hole as shown.
CAUTION:
Do not start the engine while checking the fluid level.
3. Install the new gasket on the filler plug and install the filler plug
in the transfer. Tighten the filler plug to specification.
CAUTION:
Do not reuse the gasket.Drain plug : Refer to TF-128, "
Disassembly and As-
sembly".
SDIA3208E
Fluid capacity and grade : Refer to MA-10, "Fluids
and Lubricants".
Filler plug : Refer to TF-128, "
Disassembly and
Assembly".
SDIA3209E
Filler plug : Refer to TF-128, "Disassembly and
Assembly".
SDIA3209E

TF-18
< SERVICE INFORMATION >
ALL-MODE 4WD SYSTEM
LINE PRESSURE SWITCH
• With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
• The line pressure switch determines whether or not adequate line pressure has built up under different oper-
ating conditions.
• The line pressure switch turns ON when line pressure is produced.
• The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
• The clutch pressure switch determines whether or not adequate clutch pressure has built up under different
operating conditions.
• The clutch pressure switch turns ON when clutch pressure is produced.
• The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
TRANSFER FLUID TEMPERATURE SENSOR
The transfer temperature sensor detects the transfer fluid temperature and sends a signal to the transfer con-
trol unit.
TRANSFER CONTROL UNIT
• Transfer control unit controls transfer control device by input signals of each sensor and each switch.
• Self-diagnosis can be done.
TRANSFER CONTROL DEVICE
The transfer control device changes the state of transfer assembly between 2WD, AUTO, 4H⇔4LO with the
2WD, AUTO, 4H and 4LO signals of 4WD shift switch.
NOTE:
• To shift between 4H⇔4LO, stop the vehicle, depress the brake pedal and shift the transmission selector to
the "N" position. Depress and turn the 4WD shift switch. The shift switch will not shift to the desired mode if
the transmission is not in "N" or the vehicle is moving. The 4LO indicator lamp will be lit when the 4LO is
engaged.
• Actuator motor and actuator position switch are integrated.
4WD SHIFT SWITCH AND INDICATOR LAMP
4WD Shift Switch
The 4WD shift switch allows selection from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp
• Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine is
running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp
• Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4WD WARNING LAMP
Turns ON or FLASH when there is a malfunction in 4WD system.
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF for approximately 1
second after the engine starts if system is normal.
4WD Warning Lamp Indication
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to “OFF” or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is “OFF”.Flickers once every 2 sec-
onds.

TF-20
< SERVICE INFORMATION >
ALL-MODE 4WD SYSTEM
CAN Communication
INFOID:0000000003532519
SYSTEM DESCRIPTION
Refer to LAN-4.
ABS actuator and electric unit
(control unit)Transmits vehicle speed signal via CAN communication to transfer control unit.
TCMTransmits the following signals via CAN communication to transfer control unit.
• Output shaft revolution signal
• A/T position indicator signal (PNP switch signal)
ECMTransmits the following signals via CAN communication to transfer control unit.
• Engine speed signal
• Accelerator pedal position signal Component parts Function