2005 INFINITI QX4 wheel

COLLISION DIAGNOSIS
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Revision: October 20052005 QX56
COLLISION DIAGNOSISPFP:00015
For Frontal CollisionEHS001SN
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" .
SRS INSPECTION (FOR FRONTAL COLLISION)
Part SRS is activated SRS is NOT activated
Driver air bag module If the driver air bag
has deployed:
REPLACE
Install with new fas-
teners.If the driver air bag has NOT been activated:
1. Remove driver air bag module. Check harness cover and connectors for damage,
terminals for deformities, and harness for binding.
2. Install driver air bag module into the steering wheel to check fit and alignment with
the wheel.
3. If no damage is found, reinstall with new fasteners.
4. If damaged—REPLACE. Install driver air bag modules with new fasteners.
Front passenger air
bag moduleIf the front passenger
air bag has deployed:
REPLACE
Install with new fas-
teners.If the front passenger air bag has NOT been activated:
1. Remove front passenger air bag module. Check harness cover and connectors for
damage, terminals for deformities, and harness for binding.
2. Install front passenger air bag module into the instrument panel to check fit with the
instrument panel.
3. If no damage is found, reinstall with new fasteners.
4. If damaged—REPLACE. Install front passenger air bag modules with new fasten-
ers.
Crash zone sensor If any of the front air
bags or seat belt pre-
tensioners* have
been activated:
REPLACE the crash
zone sensor and
bracket with new fas-
teners.
*: Confirm seat belt
pre-tensioner activa-
tion using CONSULT-
II only.If the front air bags or seat belt pre-tensioners have NOT been activated:
1. Remove the crash zone sensor. Check harness connectors for damage, terminals
for deformities, and harness for binding.
2. Check for visible signs of damage (dents, cracks, deformation) of the crash zone
sensor and bracket.
3. Install the crash zone sensor to check fit.
4. If no damage is found, reinstall with new fasteners.
5. If damaged—REPLACE the crash zone sensor and bracket with new fasteners.
Seat belt pre-ten-
sioner assemblies
(All applicable loca-
tions: buckle, reel, lap
outer)If either the driver or
passenger seat belt
pre-tensioner* has
been activated:
REPLACE all seat
belt pre-tensioner
assemblies with new
fasteners.
*: Confirm seat belt
pre-tensioner activa-
tion using CONSULT-
II only.If the pre-tensioners have NOT been activated:
1. Remove seat belt pre-tensioners.
Check harness cover and connectors for damage, terminals for deformities, and
harness for binding.
2. Check belts for damage and anchors for loose mounting.
3. Check retractor for smooth operation.
4. Check seat belt adjuster for damage.
5. Check for deformities of the center pillar inner.
6. If the center pillar inner has no damage, REPLACE the seat belt pre-tensioner
assembly.
7. If no damage is found, reinstall seat belt pre-tensioner assembly.
8. If damaged—REPLACE. Install the seat belt pre-tensioners with new fasteners.
Diagnosis sensor unit If any of the SRS
components have
been activated:
REPLACE the diag-
nosis sensor unit.
Install with new fas-
teners.If none of the SRS components have been activated:
1. Check case for dents, cracks or deformities.
2. Check connectors for damage, and terminals for deformities.
3. If no damage is found, reinstall with new fasteners.
4. If damaged—REPLACE. Install diagnosis sensor unit with new fasteners.

SRS-62
COLLISION DIAGNOSIS
Revision: October 20052005 QX56
For Side and Rollover CollisionEHS001SO
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.
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 harness.
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

ALL-MODE 4WD SYSTEM
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Revision: October 20052005 QX56
Ta b l e 1
Ta b l e 2
*: After 2.5 seconds have elapsed.

4WD shift switch, PNP switch, Neutral-4LO switch, vehicle speed sensor and throttle position sensor are
used in conjunction with the transfer motor.
WAIT DETECTION SWITCH

The wait detection switch operates when there is “circulating” torque produced in the propeller shaft
(L→H) or when there is a phase difference between 2-4 sleeve and clutch drum (H→L). After the release
of the “circulating” torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts.
A difference may occur between the operation of the 4WD shift switch and actual drive mode. At this
point, the wait detection switch senses an actual drive mode.

The wait detection switch operates as follows.
–4WD lock gear (clutch drum) locked: ON
–4WD lock gear (clutch drum) released: OFF

The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the
vehicle drive mode.
NEUTRAL-4LO SWITCH
The neutral-4LO switch detects that transfer gear is in neutral or 4LO (or shifting from neutral to 4LO) condi-
tion by L-H shift fork position.
ATP SWITCH
ATP switch detects if transfer gear is in a neutral condition by L-H shift fork position.
NOTE:
Transfer gear may be in a neutral condition in 4H-4LO.
2-4WD SHIFT SOLENOID VALVE
The 2-4WD shift solenoid valve operates to apply oil pressure to the wet-multiplate clutch, depending on the
drive mode. The driving force is transmitted to the front wheels through the clutch so the vehicle is set in the
4WD mode. Setting the vehicle in the 2WD mode requires no pressure buildup. In other words, pressure force
applied to the wet-multiplate clutch becomes zero.
CLUTCH PRESSURE SOLENOID VALVE
The clutch pressure solenoid valve distributes torque (front and rear) in AUTO mode.
PNP switch “R” position VFF (Vehicle speed) A/T position Motor relay drive command
ON — R ON
OFF0Positions other than the “P” or
“N” positionsON
—“P” or “N” position (See Table
2.)—
0 < VFF ≤ 50 km/h (31 MPH) — ON
50 km/h (31 MPH) < VFF < 55
km/h (34 MPH)—HOLD
55 km/h (34 MPH) ≤ VFF — OFF
A/T position N-4L SW 4WD modeThrottle position
0 - 0.07/8 0.07/8 - 1/8 1/8 - MAX
NOFFLOCK (4H) ON ON ON
Positions other than
the LOCK position
(2WD or AUTO)OFF* HOLD ON
ON — OFF* HOLD ON
P — — OFF* HOLD ON

TF-18
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
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
operating 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 differ-
ent 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.

TF-20
ALL-MODE 4WD SYSTEM
Revision: October 20052005 QX56
COMPONENTS FUNCTION
CAN CommunicationEDS002HC
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .
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.
ATP warning lampIndicates 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.
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

TF-34
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
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-50, "SELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)" (with CONSULT-II) or TF-50, "SELF-DIAGNOSTIC PROCEDURE (WITHOUT CON-
SULT-II)" (without CONSULT-II).
Flash rapidly>>GO TO TF-128, "
4WD Warning Lamp Flashes Rapidly" .
Flash slowly>>GO TO TF-129, "
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-130, "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-131, "
4WD System Does Not Operate" .
Trouble Diagnosis Chart for SymptomsEDS002HI
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-50, "Self-diagnostic Procedure" .
Symptom Condition Check item Reference page
4WD shift indicator lamp and 4LO indicator
lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator
lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-117
Transfer shut off relay
Combination meter
4WD warning lamp does not turn ON
(4WD warning lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-121
Transfer shut off relay
Combination meter

TROUBLE DIAGNOSIS
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Revision: October 20052005 QX56
NOTE:

Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not
a malfunction.

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.
4WD shift indicator lamp or 4LO indicator
lamp does not changeEngine running4WD shift switch
TF-123
Wait detection switch
Neutral-4LO switch
ATP switch
2-4WD solenoid
Transfer control device
Actuator motor
Actuator position switch
Transfer inner parts
ATP warning lamp turns ON Engine runningCAN communication line
TF-125
4WD shift switch
PNP switch signal
ATP switch
Combination meter
Transfer inner parts
4LO indicator lamp repeats flashing Engine runningWait detection switch
TF-127
Neutral-4LO switch
Transfer inner parts
4WD warning lamp flashes rapidly (2 times/
second)While drivingTransfer fluid temperature
TF-128
Tire size is different between front and
rear of vehicle
4WD warning lamp flashes slowly
(1 time/2 seconds)While drivingTire size is different between front and
rear of vehicle.
TF-129
Transfer fluid temperature
Clutch pressure switch
Heavy tight-corner braking symptom occurs
(See NOTE.)

While driving

AUTO mode

Steering wheel is
turned fully to either
sideCAN communication line
TF-130
4WD shift switch
Accelerator pedal position signal
Clutch pressure solenoid
Transfer inner parts
4WD system does not operate While driving4WD shift switch
TF-131
Clutch pressure switch
Transfer inner parts Symptom Condition Check item Reference page

TF-36
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Transfer Control Unit Input/Output Signal Reference ValuesEDS0 02 HJ
TRANSFER CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-II
Monitored item [Unit] Content Condition Display value
VHCL/S SEN·FR [km/h]
or [mph]Wheel speed (Front
wheel)Vehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indi-
cation on speed-
ometer (Inside of
±10%)
VHCL/S SEN·RR [km/h]
or [mph]Wheel speed (Rear
wheel)Vehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indi-
cation on speed-
ometer (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 indi-
cation on tachom-
eter
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
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
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