2007 INFINITI QX56 brake

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.

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-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 >
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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

TROUBLE DIAGNOSIS
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< SERVICE INFORMATION >
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• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is "4H" or "4LO", steering wheel is turned fully to either side.
Transfer Control Unit Input/Output Signal Reference ValueINFOID:0000000003532526
TRANSFER CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-II
Monitored item [Unit] Content Condition Display value
VHCL/S SEN·FR [km/h]
or [mph]Front wheel speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
VHCL/S SEN·RR [km/h]
or [mph]Rear wheel speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
ENGINE SPEED [rpm] Engine speedEngine stopped
(Engine speed: Less than 400 rpm)0 rpm
Engine running
(Engine speed: 400 rpm or more)Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V]Accelerator pedal posi-
tion (APP) sensor signal
voltageAccelerator pedal: Release Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V]Transfer fluid tempera-
ture signal voltageTransfer fluid temperature approx. 20 - 80°C (68 - 176°F) Approx. 1.1 - 0.3V
BATTERY VOLT [V]Power supply voltage for
transfer control unitIgnition switch: ON Battery voltage
2WD SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF]Condition of neutral-4LO
switch• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON

TF-36
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
ATP SWITCH [ON/OFF] Condition of ATP switch• Vehicle stopped
• Engine running
• A/T selector lever “N”
• Brake pedal depressed4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is
operating.) ON
Except the above OFF
WAIT DETCT SW [ON/
OFF]Condition of wait detec-
tion switch• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
LINE PRES SW [ON/
OFF]Condition of line pres-
sure switch• A/T selector lever “D” position
• 4WD shift switch: 2WD, AUTO or 4HON
• Except the above
• The vehicle has been left at
room temperature for 5
minutes and more with ig-
nition switch in “OFF” posi-
tion.• Ignition switch: ON
• A/T selector lever: “P”
or "N" position
• 4WD shift switch: other
than AUTOOFF
CL PRES SW [ON / OFF]Condition of clutch pres-
sure switch• Vehicle stopped
• Engine running
• A/T selector lever “D” position
• 4WD shift switch: AUTO or 4H (“Wait” function is not op-
erating.)ON
• Vehicle stopped
• Engine running
• 4WD shift switch: 2WD (“Wait” function is not operat-
ing.)OFF
N POSI SW AT [ON/
OFF]Input condition from A/T
PNP switch• Vehicle stopped
• Engine running
• Brake pedal depressedA/T selector lever posi-
tion: NON
Except the above OFF
R POSI SW AT [ON/
OFF]Input condition from A/T
PNP switch• Vehicle stopped
• Engine running
• Brake pedal depressedA/T selector lever posi-
tion: RON
Except the above OFF
P POSI SW AT [ON/OFF]Input condition from A/T
PNP switch• Vehicle stopped
• Engine running
• Brake pedal depressedA/T selector lever posi-
tion: PON
Except the above OFF
ABS OPER SW [ON/
OFF]Condition of ABS operat-
ingABS is operating. ON
ABS is not operating. OFF
VDC OPER SW [ON/
OFF]Condition of VDC operat-
ingVDC is operating. ON
VDC is not operating. OFF
TCS OPER SW [ON/
OFF]Condition of TCS operat-
ingTCS is operating. ON
TCS is not operating. OFF
THROTTLE POSI [0.0/8]Condition of throttle
openingWhen depressing accelerator pedal
(Value rises gradually in response to throttle position.)0.0/8 - 8.0/8
4WD MODE [AUTO/
LOCK/2WD/4L]Control status of 4WD
(Output condition of 4WD
shift indicator lamp and
4LO indicator lamp)• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD 2WD
4WD shift switch: AUTO AUTO
4WD shift switch: 4H LOCK
4WD shift switch: 4LO 4L Monitored item [Unit] Content Condition Display value

TROUBLE DIAGNOSIS
TF-37
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VHCL/S COMP [km/h] or
[mph]Vehicle speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
COMP CL TORQ [kgm]Condition of control
torque• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD 0 kg-m
4WD shift switch: AUTO39 - 1,353 N·m
(4 - 138 kg-m, 29 -
998 ft-lb)
4WD shift switch: 4H or
4LO1,353 N·m
(138 kg-m, 998 ft-
lb)
DUTY SOLENOID [%]Condition of clutch pres-
sure solenoid• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
2-4WD SOL [ON/OFF]Condition of 2-4WD shift
solenoid valve• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
2-4WD SOL MON [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
ON 4WD shift switch: 4H
4WD shift switch: 4LO
4WD shift switch: AUTO
(“Wait” function is operat-
ing.)OFF
4WD shift switch: 4H
(“Wait” function is operat-
ing.)OFF
MOTOR RELAY [ON/
OFF]Condition of transfer mo-
tor relay• Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting
to “P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever “P” or “N” po-
sition)ON
4WD shift switch: 4H (A/T
selector lever “P” posi-
tion)OFF
("ON" for approx. 2
sec. after shifting
to “P”.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
“P” position)ON Monitored item [Unit] Content Condition Display value

TF-38
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output• Accelerator pedal de-
pressed
• Vehicle stopped
• Engine running
• Brake pedal depressed4WD shift switch: 2WD OFF
4WD shift switch: AUTO
or 4LO (A/T selector lever
“P” or “N” position)OFF
("ON" for approx. 2
sec. after shifting
to “P” and “N”.)
4WD shift switch: AUTO
or 4LO (Except for A/T se-
lector lever “P” or “N” po-
sition)ON
4WD shift switch: 4H (A/T
selector lever “P” posi-
tion)OFF
("ON" for approx. 2
sec. after shifting
to “P”.)
4WD shift switch: 4H (Ex-
cept for A/T selector lever
“P” position)ON
4WD FAIL LAMP [ON/
OFF]Condition of 4WD warn-
ing lamp4WD warning lamp: ON ON
4WD warning lamp: OFF OFF
2WD IND [ON/OFF]Condition of 4WD shift in-
dicator lamp (2WD indi-
cator lamp)2WD indicator lamp of 4WD shift indicator lamp: OFF OFF
2WD indicator lamp of 4WD shift indicator lamp: ON ON
AUTO IND [ON/OFF]Condition of 4WD shift in-
dicator lamp (AUTO indi-
cator lamp)AUTO indicator lamp of 4WD shift indicator lamp: OFF OFF
AUTO indicator lamp of 4WD shift indicator lamp: ON ON
LOCK IND [ON/OFF]Condition of 4WD shift in-
dicator lamp (Lock indi-
cator lamp)Lock indicator lamp of 4WD shift indicator lamp: OFF OFF
Lock indicator lamp of 4WD shift indicator lamp: ON ON
4L IND [ON/OFF]Condition of 4LO indica-
tor lamp condition4LO indicator lamp: OFF OFF
4LO indicator lamp: ON ON
ATP IND [ON/OFF]Condition of ATP indica-
tor lamp ATP indicator lamp: ON ON
AT P i n d i c a t o r l a m p : O F F O F F
SHIFT POS SW1 [ON/
OFF]Condition of actuator po-
sition switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4LO ON
4WD shift switch: 2WD,
AUTO or 4HOFF
SHIFT POS SW2 [ON/
OFF]Condition of actuator po-
sition switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
SHIFT ACT1 [ON/OFF]Output condition to actu-
ator motor (High)• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is
operating.)ON
Except the above OFF
SHIFT AC MON1 [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is
operating.)ON
Except the above OFF
SHIFT ACT2 [ON/OFF]Output condition to actu-
ator motor (Low)• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF Monitored item [Unit] Content Condition Display value