INFINITI QX56 2006 Factory Service Manual

TF-126
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
4. CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to TF-113, "
ATP Switch" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch “ OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
–Transfer control unit harness connector E142 terminal 15 and
combination meter harness connector M24 terminal 6.
–Transfer control unit harness connector E142 terminal 40 and
combination meter harness connector M24 terminal 7.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6. CHECK ATP WARNING LAMP CIRCUIT
1. A/T selector lever in "P" position.
2. Connect combination meter harness connector and transfer control unit harness connector.
3. Disconnect ATP switch harness connector.
4. Ground the following terminal using suitable wiring.
–ATP switch harness connector F55 terminal 8 and ground.
5. Turn ignition switch “ ON”. (Do not start engine.)
Does indicator lamp turn on?
OK >> GO TO 7.
NG >> Replace combination meter. Refer to IP-13, "
COMBINA-
TION METER" .
Continuity should exist.
WDIA0149E
40 to 7: Continuity should not exist.
7 to 40: Continuity should exist.
WDIA0150E
SDIA2769E

TROUBLE DIAGNOSIS FOR SYMPTOMSTF-127
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Revision: November 2009 2006 QX56
7. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 8.
8. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 9.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
9. CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-146, "
Disassembly and Assembly" .
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.
4LO Indicator Lamp Repeats FlashingEDS002HQ
SYMPTOM:
4LO lamp keeps flashing.
DIAGNOSTIC PROCEDURE
1. CONFIRM THE SYMPTOM
1. Set 4WD shift switch to “2WD”.
2. Move vehicle forward and backward, or drive straight increasing or decreasing under 20 km/h (12 MPH).
Dose 4WD shift indicator lamp keep flashing?
YES >> GO TO 2.
NO >> Inspection End.
2. CHECK SYSTEM FOR WAIT DETECTION SWITCH
Perform trouble diagnosis for wait detection switch system. Refer to TF-66, "
Wait Detection Switch" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK SYSTEM FOR NEUTRAL-4LO SWITCH
Perform trouble diagnosis for neutral-4LO switch system. Refer to TF-59, "
Neutral-4LO Switch" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 5.

TF-128
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 6.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
6. CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-146, "
Disassembly and Assembly" .
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.
4WD Warning Lamp Flashes RapidlyEDS002HR
SYMPTOM:
While driving, 4WD warning lamp flashes rapidly.
NOTE:
Rapid flashing: 2 times/second
DIAGNOSTIC PROCEDURE
1. CHECK TIRE
Check the following.

Tire pressure

Wear condition

Longitudinal tire size (There is no difference between longitudinal tires.)
OK or NG
OK >> GO TO 2.
NG >> Repair or replace damaged parts.
2. CHECK 4WD WARNING LAMP
Stop the vehicle and allow it to idle for a short period of time.
Does flashing stop?
YES >> Inspection End.
NO >> GO TO 3.
3. CHECK TRANSFER FLUID TEMPERATURE
Perform trouble diagnosis for transfer fluid temperature system. Refer to TF-102, "
Transfer Fluid Temperature"
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 5.

TROUBLE DIAGNOSIS FOR SYMPTOMSTF-129
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Revision: November 2009 2006 QX56
5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> Inspection End.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
4WD Warning Lamp Flashes SlowlyEDS002HS
SYMPTOM:
While driving, 4WD warning lamp flashes slowly. (When continuing to flash until turning ignition
switch OFF.)
NOTE:
Slow flashing: 1 time/2 seconds
DIAGNOSTIC PROCEDURE
1. CHECK TIRE
Check the following.

Tire pressure

Wear condition

Longitudinal tire size (There is no difference between longitudinal tires.)
OK or NG
OK >> GO TO 2.
NG >> Repair or replace damaged parts.
2. CHECK TRANSFER FLUID TEMPERATURE
Perform trouble diagnosis for transfer fluid temperature system. Refer to TF-102, "
Transfer Fluid Temperature"
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK CLUTCH PRESSURE SWITCH
Perform trouble diagnosis for clutch pressure switch system. Refer to TF-105, "
Clutch Pressure Switch" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 5.
5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> Inspection End.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

TF-130
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
Heavy Tight-corner Braking Symptom OccursEDS002HT
SYMPTOM:
Heavy tight-corner braking symptom occurs when vehicle is driven in AUTO mode and steering wheel
is turned fully to either side.
DIAGNOSTIC PROCEDURE
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.
1. CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to TF-50, "
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)" .
Is "CAN COMM CIRCUIT [U1000]" displayed?
YES >> Perform trouble diagnosis for CAN communication line. Refer to TF-113, "CAN Communication
Line" .
NO >> GO TO 2.
2. CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to TF-62, "
4WD Shift Switch" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK ACCELERATOR PEDAL POSITION SIGNAL CIRCUIT
Perform self diagnosis for ECM. Refer to EC-49, "
Emission-related Diagnostic Information" .
Is any malfunction deteced by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 4.
4. CHECK SYSTEM FOR CLUTCH PRESSURE SOLENOID
Perform trouble diagnosis for clutch pressure solenoid system. Refer to TF-105, "
Clutch Pressure Switch" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 6.
6. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 7.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

TROUBLE DIAGNOSIS FOR SYMPTOMSTF-131
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Revision: November 2009 2006 QX56
7. CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-146, "
Disassembly and Assembly" .
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.
4WD System Does Not OperateEDS002HU
SYMPTOM:
The vehicle cannot be put into 4WD mode. (Hydraulic system failure)
DIAGNOSTIC PROCEDURE
1. CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to TF-62, "
4WD Shift Switch" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace damaged parts.
2. CHECK SYSTEM FOR CLUTCH PRESSURE SWITCH
Perform trouble diagnosis for clutch pressure switch system. Refer to TF-105, "
Clutch Pressure Switch" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. SYMPTOM CHECK
Check again.
OK or NG
OK >> Inspection End.
NG >> GO TO 4.
4. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 5.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
5. CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to TF-146, "
Disassembly and Assembly" .
2. Check transfer inner parts.
OK or NG
OK >> Inspection End.
NG >> Repair or replace damaged parts.

TF-132
TRANSFER CONTROL UNIT
Revision: November 20092006 QX56
TRANSFER CONTROL UNITPFP:33084
Removal and InstallationEDS002IS
REMOVAL
1. Set transfer state as 2WD when 4WD shift switch is at 2WD, or as AUTO when 4WD shift switch is at
AUTO.
CAUTION:
When removing transfer control unit, transfer state must be at 2WD or AUTO.
2. Turn the ignition switch OFF and disconnect negative battery terminal.
3. Remove the glove box assembly. Refer to IP-14, "
Lower Instrument Panel RH and Glove Box" .
4. Disconnect the two transfer control unit connectors.
5. Remove the transfer control unit bolts.
6. Remove the transfer control unit.
INSTALLATION
Installation is in the reverse order of removal.

When installing the transfer control unit, tighten bolts to the specified torque.
CAUTION:

Do not connect harness connector to transfer control unit when 4WD shift switch is at 4LO.

After the installation, check perform self-diagnosis. Refer to TF-50, "Self-diagnostic Procedure" . If NG,
adjust position between transfer assembly and transfer control unit. Refer to TF-4, "
Precautions for Trans-
fer Assembly and Transfer Control Unit Replacement" .
BDIA0014E
Transfer control unit bolts : 5.1 N·m (0.52 kg-m, 45 in-lb)

FRONT OIL SEALTF-133
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Revision: November 2009 2006 QX56
FRONT OIL SEALPFP:38189
Removal and InstallationEDS003B8
REMOVAL
1. Partially drain the transfer fluid. Refer to TF-11, "DRAINING" .
2. Remove the front propeller shaft. Refer to PR-5, "
REMOVAL" .
3. Remove the companion flange self-lock nut using Tool.
4. Put a matching mark on top of the front drive shaft in line with the mark on the companion flange.
CAUTION:
Use paint to make the matching mark on the front drive
shaft. Do not damage the front drive shaft.
5. Remove the companion flange using suitable tool.
6. Remove the oil seal from the front case using Tool. CAUTION:
Do not damage front case.Tool number : KV40104000 ( — )
SDIA2657E
SDIA2658E
WDIA0193E
Tool number : KV381054S0 (J-34286)
LDIA0144E

TF-134
FRONT OIL SEAL
Revision: November 20092006 QX56
INSTALLATION
1. Install the new oil seal until it is flush with the end face of the
front case using Tool.
CAUTION:

Do not reuse oil seal.

Apply petroleum jelly to oil seal.
2. Align the matching mark of the front drive shaft with the match- ing mark of the companion flange, then install the companion
flange.
3. Install the new self-lock nut. Tighten to the specified torque using Tool. Refer to TF-146, "
COMPONENTS" .
CAUTION:
Do not reuse self-lock nut.
4. Install the front propeller shaft. Refer to PR-5, "
INSTALLATION"
.
5. Refill the transfer with fluid and check fluid level. Refer to TF-11,
"TRANSFER FLUID" .
6. Check the transfer for fluid leakage. Refer to TF-11, "
FLUID
LEAKAGE AND FLUID LEVEL" .
Tool number : KV38100500 ( — )
SDIA2662E
SDIA2658E
Tool number : KV40104000 ( — )
LDIA0147E

REAR OIL SEALTF-135
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Revision: November 2009 2006 QX56
REAR OIL SEALPFP:33140
Removal and InstallationEDS003B9
REMOVAL
1. Partially drain the transfer fluid. Refer to TF-11, "DRAINING" .
2. Remove the rear propeller shaft. Refer to PR-9, "
REMOVAL" .
3. Remove the dust cover from the rear case. CAUTION:
Do not damage the rear case.
4. Remove the rear oil seal from the rear case using Tool. CAUTION:
Do not damage the rear case.
INSTALLATION
1. Install the new oil seal until it is flush with the end face of the rearcase using Tool.
CAUTION:

Do not reuse oil seal.

Apply petroleum jelly to oil seal.
2. Apply petroleum jelly to the circumference of the new dust cover. Position the new dust cover using the identification mark as
shown.
CAUTION:

Do not reuse dust cover.

Position the identification mark at the position shown.
WDIA0127E
Tool number : KV381054S0 (J-34286)
LDIA0139E
Tool number : ST30720000 (J-25405)
LDIA0140E
SDIA3436E