2007 INFINITI QX56 warning

SRS-34
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3.CHECK HARNESS CONNECTIONS BETWEEN AIR BAG DIAGNOSIS SENSOR UNIT AND COMBINA-
TION METER
Inspect the harness and connectors between the air bag diagnosis sensor unit and the combination meter.
Do the harness or connectors have any visible damage?
Yes >> Replace harness.
No >> GO TO 4.
4.CHECK COMBINATION METER
Disconnect the air bag diagnosis sensor unit harness connectors and turn ignition switch ON.
Does
“AIR BAG” warning lamp turn on?
Yes >> Replace the air bag diagnosis sensor unit. Refer to SRS-47, "Removal and Installation" .
No >> Replace the combination meter. Refer to IP-10, "
Removal and Installation" .

SRS-50
< SERVICE INFORMATION >
COLLISION DIAGNOSIS
For Side and Rollover Collision
INFOID:0000000003532883
Check the SRS components using the following table.
• After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to SRS-
20, "SRS Operation Check" .
WHEN SRS IS ACTIVATED IN THE SIDE OR ROLLOVER COLLISION
1. Replace the following components:
- Front seat back assembly (on the side on which side air bag is activated)
- Diagnosis sensor unit
- (LH or RH) side air bag (satellite) sensor (on the side on which side air bag is activated)
2. Check the SRS components and the related parts using the following table.
- Replace any SRS components and the related parts showing visible signs of damage (dents, cracks,
deformation).
3. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
WHEN SRS IS NOT ACTIVATED IN THE SIDE OR ROLLOVER COLLISION
1. Check the SRS components and the related parts using the following table.
- If the front seat back assembly is damaged, the front seat back assembly must be replaced.
2. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
SRS INSPECTION (FOR SIDE AND ROLLOVER COLLISION)
Steering wheel 1. Visually check steering wheel for deformities.
2. Check harness (built into steering wheel) and connectors for damage, and terminals for deformities.
3. Install driver air bag module into the steering wheel to check fit and alignment with the wheel.
4. Check steering wheel for excessive free play.
5. If no damage is found, reinstall.
6. If damaged—REPLACE.
Spiral cable If the driver front air
bag has deployed:
REPLACE the spiral
cable.If the driver front air bag has not deployed:
1. Visually check spiral cable and combination switch for damage.
2. Check connectors and protective tape for damage.
3. Check steering wheel for noise, binding or heavy operation.
4. If no damage is found, reinstall.
5. If damaged—REPLACE.
Occupant classifica-
tion system (Passen-
ger seat)1. Remove passenger seat.
2. Check control unit case for dents, cracks of deformities.
3. Check connectors and pressure sensor tube for damage, and terminals for deformities.
4. Check seat frame and cushion pan for dents or deformities.
5. If no damage is found, reinstall seat with new fasteners.
6. If damaged — REPLACE seat cushion assembly with new fasteners.
Harness and connec-
tors1. Check connectors for poor connection, damage, and terminals for deformities.
2. Check harness for binding, chafing, cuts, or deformities.
3. If no damage is found, reinstall the harness and connectors.
4. If damaged—REPLACE the damaged harness. Do not attempt to repair, splice or modify any SRS har-
ness.
Instrument panel If the passenger front
air bag has deployed:
REPLACE the instru-
ment panel assembly.If the passenger front air bag has NOT deployed:
1. Visually check instrument panel for damage.
2. If no damage is found, reinstall the instrument panel.
3. If damaged—REPLACE the instrument panel. Part SRS is activated SRS is NOT activated

TF-1
DRIVELINE/AXLE
C
E
F
G
H
I
J
K
L
M
SECTION TF
A
B
TF
N
O
P
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 >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
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.

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.

ALL-MODE 4WD SYSTEM
TF-19
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
*: When 4WD warning lamp is ON, all the 4WD shift indicator lamps turn OFF.
ATP WARNING LAMP
Even if A/T selector lever is in “P” position, vehicle may move because A/T parking mechanism does not oper-
ate when transfer is under neutral condition. ATP warning lamp is turned on so as to indicate this condition to
the driver.
SchematicINFOID:0000000003532518
COMPONENTS FUNCTION
High fluid temperature in transfer unitWhen fluid temperature is high or fluid temperature sensor cir-
cuit is shorted, it flickers twice every second.
It turns OFF when fluid temperature becomes normal.Flickers twice a second.
Other than above (System is normal.) Lamp is OFF. OFFCondition Content 4WD warning lamp
WDIA0164E
Component parts Function
Transfer control unit Controls transfer control device and control valves.
Transfer control device Actuator motor and actuator position switch are integrated so as to switch driving types.
2-4WD shift solenoid valve Controls oil pressure and allows selection between 2WD and 4WD.
Clutch pressure solenoid valve Controls oil pressure and distributes torque (front and rear).
Line pressure switch Detects line pressure.
Clutch pressure switch Detects clutch pressure.
Transfer fluid temperature sen-
sorDetects transfer fluid temperature.
Wait detection switch Detects whether or not 4WD lock gear is locked.
Neutral-4LO switch Detects that transfer is under neutral-4LO condition (or shifting through neutral).
ATP switch Detects that transfer is under neutral condition.
4WD shift switch Allows selection from 2WD, AUTO, 4H or 4LO.
4WD warning lamp• Illuminates if malfunction is detected in electrical system of 4WD system.
• There is 1 blink every 2 seconds if rotation difference of front wheels and rear wheels is large.
• There is 2 blinks every 1 second if high transfer fluid temperature is detected.
AT P w a r n i n g l a m pIndicates that A/T parking mechanism does not operate when A/T selector lever is in “P” position and
transfer is under neutral condition.
4WD shift indicator lamp Displays driving condition selected by 4WD shift switch.
4LO indicator lamp Displays 4LO condition.

TF-32
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
• The purpose of the test is to determine overall performance of
transfer and analyze causes of problems.
• When a malfunction is found in any part of transfer, perform the
road test to locate the malfunction area and repair the malfunction
parts.
• The road test consists of the following three parts.
- Check before engine is started. Refer to "CHECK BEFORE
ENGINE IS STARTED".
- Check at idle. Refer to "CHECK AT IDLE" .
- Cruise test. Refer to "CRUISE TEST".
CHECK BEFORE ENGINE IS STARTED
1.CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to “OFF” position.
3. Move A/T selector lever to “P” position.
4. Set 4WD shift switch to “2WD” position.
5. Turn ignition switch to “ON” position. (Do not start engine.)
Does 4WD shift indicator lamp turn ON for approximately 1 second?
YES >> GO TO 2.
NO >> Go to TF-107, "
4WD Shift Indicator Lamp or 4LO Indicator Lamp Does Not Change".
2.CHECK 4WD WARNING LAMP
1. Turn ignition switch to “OFF” position.
2. Move A/T selector lever to “P” position.
3. Set 4WD shift switch to “2WD” position.
4. Turn ignition switch to “ON” position. (Do not start engine.)
Does 4WD warning lamp turn ON?
YES >> GO TO "CHECK AT IDLE".
NO >> GO TO TF-104, "
4WD Warning Lamp Does Not Turn ON".
CHECK AT IDLE
1.CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface and engage the parking brake.
2. Turn ignition switch to “OFF” position.
3. Move A/T selector lever to “P” position.
4. Set 4WD shift switch to “2WD” position.
5. Start engine.
Does 4WD shift indicator lamp turn ON?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK 4WD WARNING LAMP
Check 4WD warning lamp state?
Is 4WD warning lamp turned ON?
YES >> Perform the self-diagnosis. Refer to TF-48, "Self-Diagnosis Procedure" or TF-48, "Self-Diagnosis
Procedure".
NO >> Go to TF-102, "
4WD Shift Indicator Lamp and 4LO Indicator Lamp Do Not Turn ON".
3.CHECK 4WD SHIFT INDICATOR AND 4LO INDICATOR OPERATION
SMT089D

TROUBLE DIAGNOSIS
TF-33
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
1. Brake pedal depressed.
2. Move A/T selector lever to “N” position.
3. Set 4WD shift switch to “2WD”, “AUTO”, “4H”, “4LO”, “4H”,
“AUTO” and “2WD” in order. (Stay at each switch position for at
least 1 second.)
Do 4WD shift indicator and 4LO indicator lamps change properly?
Does buzzer sound?
YES >> GO TO "CRUISE TEST".
NO >> GO TO TF-107, "
4WD Shift Indicator Lamp or 4LO Indi-
cator Lamp Does Not Change" .
CRUISE TEST
1.CHECK INPUT SIGNAL
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Move A/T selector lever to “P” position.
4. Set 4WD shift switch to “AUTO” position.
5. Start engine.
6. Drive vehicle for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
Check 4WD warning lamp turned ON?
On steady>>Perform the self-diagnosis. Refer to TF-48, "Self-Diagnosis Procedure" or TF-48, "Self-Diagno-
sis Procedure".
Flash rapidly>>GO TO T F - 111 , "
4WD Warning Lamp Flashes Rapidly" .
Flash slowly>>GO TO TF-112, "
4WD Warning Lamp Flashes Slowly".
NO >> GO TO 2.
2.CHECK TIGHT CORNER BRAKING SYMPTOM (1)
1. Set 4WD shift switch to “AUTO” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> GO TO TF-113, "Heavy Tight-corner Braking Symptom Occurs".
NO >> GO TO 3.
3.CHECK TIGHT CORNER BRAKING SYMPTOM (2)
1. Set 4WD shift switch to “4HI” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> Inspection End.
NO >> GO TO TF-114, "
4WD System Does Not Operate" .
WDIA0136E