service INFINITI QX56 2007 Factory Service Manual

TF-30
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
BDWA0172E

TROUBLE DIAGNOSIS
TF-31
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Inspections Before Trouble DiagnosisINFOID:0000000003532524
TRANSFER FLUID CHECK
Check fluid for leaks and fluid level. Refer to TF-11, "Inspection" .
PREPARATION FOR ROAD TEST
BDWA0173E

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

TF-34
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Trouble Diagnosis Chart by Symptom
INFOID:0000000003532525
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-48, "Self-Diagnosis Procedure" .
NOTE:
• Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a
malfunction.
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-102
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-104
Transfer shut off relay
Combination meter
4WD shift indicator lamp or 4LO indicator
lamp does not changeEngine running4WD shift switch
TF-107
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-109
4WD shift switch
PNP switch signal
ATP switch
Combination meter
Transfer inner parts
4LO indicator lamp repeats flashing Engine runningWait detection switch
TF-110
Neutral-4LO switch
Transfer inner parts
4WD warning lamp flashes rapidly (2 times/
second)While drivingTransfer fluid temperature
TF-111
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-112
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-113
4WD shift switch
Accelerator pedal position signal
Clutch pressure solenoid
Transfer inner parts
4WD system does not operate While driving4WD shift switch
TF-114
Clutch pressure switch
Transfer inner parts

TROUBLE DIAGNOSIS
TF-35
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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

TROUBLE DIAGNOSIS
TF-39
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TRANSFER CONTROL UNIT TERMINAL CONNECTOR LAYOUT
NOTE:
Data are reference value and are measured between each terminal and ground.
SHIFT AC MON2 [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: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF
T/F F SPEED [km/h] or
[mph]Displayed, but do not use.
A/T R SPEED [km/h] or
[mph]Condition of vehicle
speed sensor A/T (Revo-
lution sensor)During drivingApproximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5]Condition of A/T selector
lever positionDisplays actual A/T gear position. 1/2/3/4/5 Monitored item [Unit] Content Condition Display value
WDIA0378E
Te r m i n a lWire
colorItem Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W4WD shift indicator lamp
(2WD indicator lamp)2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
5 W/B 4WD warning lamp4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W4WD shift switch
(2WD)Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V