INFINITI QX56 2007 Factory Service Manual

TROUBLE DIAGNOSIS FOR SYSTEM
TF-69
< SERVICE INFORMATION >
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Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit. Refer to TF-115, "
Removal and Installation".
COMPONENT INSPECTION
Transfer Shift Relay
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay. Refer to TF-22, "
Location of Electrical Parts".
3. Apply 12V direct current between transfer shift relay terminals 1
and 2.
4. Check continuity between relay terminals 3 and 4, 3 and 5.
5. If NG, replace transfer shift relay.
Transfer Control Device
1. Remove transfer control device. Refer to TF-121, "Removal and Installation".
2. Check operation by applying battery voltage to transfer control
device (actuator motor) terminals 21 and 24.
CAUTION:
• Do not operate actuator motor for more than 1 second.
• Change the actuator motor position to “HIGH” when
installing.
• Be careful not to overheat the harness.
3. Check continuity between transfer control device (actuator
motor) terminals 21 and 24.
4. If NG, replace transfer control device (actuator motor). Refer to
TF-121, "
Removal and Installation".
Actuator Position SwitchINFOID:0000000003532538
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Terminal Condition Continuity
3 - 412V direct current supply between terminals 1 and 2 No
OFF Yes
3 - 512V direct current supply between terminals 1 and 2 Yes
OFF No
WIIA0291E
Terminal Actuator motor
21 (Battery voltage) - 24 (Ground) Clockwise rotate
24 (Battery voltage) - 21 (Ground) Counterclockwise rotate
WDIA0224E
21 - 24 : Approx. 0.2 Ω
SDIA2726E

TF-70
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK ACTUATOR POSITION SWITCH SIGNAL
With CONSULT-II1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “SHIFT POS SW1” and “SHIFT POS
SW2”.
Without CONSULT-II
1. Start engine.
Monitored item [Unit] Content Condition Display value
SHIFT POS SW1 [ON/
OFF]Condition of actuator posi-
tion switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4LO ON
4WD shift switch: 2WD,
AUTO or 4HOFF
SHIFT POS SW2 [ON/
OFF]Condition of actuator posi-
tion switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
27 W/LActuator position switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
44 LG/BActuator position switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
Monitored item Condition Display value
SHIFT POS SW1• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO ON
4WD shift switch:
2WD, AUTO or 4HOFF
SHIFT POS SW2• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
SDIA2714E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-71
< SERVICE INFORMATION >
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2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ACTUATOR POSITION SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer control device (actuator position
switch) harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 27 and
transfer control device (actuator position switch) harness con-
nector F58 terminal 23.
- Transfer control unit harness connector E143 terminal 44 and
transfer control device (actuator position switch) harness con-
nector F58 terminal 20.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control device (actuator position switch) harness connector.
3. Check continuity between transfer control device (actuator posi-
tion switch) harness connector F58 terminal 22 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4.CHECK ACTUATOR POSITION SWITCH
1. Remove transfer control device. Refer to TF-115, "
Removal and Installation".
Connector Terminal ConditionVoltage
(Approx.)
E14327 -
Ground• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H,
AUTO or 2WD0V
4WD shift switch: 4LOBattery
voltage
44 -
Ground• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch:
2WD, AUTO or 4HBattery
voltage
SDIA2715E
Continuity should exist.
SDIA2716E
Continuity should exist.
SDIA2717E

TF-72
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2. Check operation by applying battery voltage to transfer control
device (actuator motor) terminals 21 and 24.
CAUTION:
• Do not operate actuator motor for more than 1 second.
• Change the actuator motor position to “HIGH” when
installing.
• Be careful not to overheat the harness.
OK or NG
YES >> GO TO 5.
NO >> Replace transfer control device (actuator motor). Refer to TF-121, "
Removal and Installation".
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
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 DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control device. Refer to TF-121, "
Removal and Installation".
COMPONENT INSPECTION
1. Remove transfer control device. Refer to TF-121, "Removal and Installation".
2. Check operation by applying battery voltage to transfer control
device (actuator motor) terminals 21 and 24.
CAUTION:
• Do not operate actuator motor for more than 1 second.
• Change the actuator motor position to “HIGH” when
installing.
• Be careful not to overheat the harness.
3. If NG, replace transfer control device (actuator motor). Refer to TF-121, "
Removal and Installation".
Transfer Control DeviceINFOID:0000000003532539
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Terminal Continuity Continuity
24 (Battery voltage) - 21
(Ground)20 - 22 Yes
22 - 23 No
21 (Battery voltage) - 24
(Ground)22 - 23 Yes
20 - 22 No
LDIA0101E
Terminal Continuity Continuity
24 (Battery voltage) - 21
(Ground)20 - 22 Yes
22 - 23 No
21 (Battery voltage) - 24
(Ground)22 - 23 Yes
20 - 22 No
LDIA0101E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-73
< SERVICE INFORMATION >
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Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK POWER SUPPLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector
terminal and ground.
Monitored item [Unit] Content Condition Display value
SHIFT AC MON1 [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4H to
4LO (“Wait” function is op-
erating.)ON
Except the above OFF
SHIFT AC MON2 [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is oper-
ating.)ON
Except the above OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
16 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
22 Y/R Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relayIgnition switch: ON 0V
Ignition switch: OFF Battery voltage
33 R/LTransfer shift high relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
42 P/GTransfer shift low relay moni-
tor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
Connector Terminal Voltage (Approx.)
E14216 - Ground
0V
22 - Ground
E143 30 - Ground Battery voltage
SDIA2834E

TF-74
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 2.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 10A fuse No. 26 located in the fuse and fusible link box. Refer to PG-3
.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector E143 terminal 30.
• Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 3.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 5 and
transfer control unit harness connector E142 terminal 22.
• Transfer shut off relay. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit".
2.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connec-
tor E142 terminals 3, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.CHECK ACTUATOR MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay. Refer to TF-22, "
Location of Electrical Parts".
3. Check voltage between transfer shift high relay harness connec-
tor E46 terminal 5 (A), transfer shift low relay harness connector
E47 terminal 5 (B) and ground.
Connector Terminal Voltage (Approx.)
E14216 - Ground
Battery voltage
22 - Ground
E143 30 - Ground 0V
SDIA2835E
Continuity should exist.
SDIA2691E
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0310E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-75
< SERVICE INFORMATION >
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4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer shift high relay harness connec-
tor E46 terminal 5 (A), transfer shift low relay harness connector
E47 terminal 5 (B) and ground.
OK or NG
OK >> GO TO 4.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 20A fuse No. 57 located in the fuse and relay box. Refer to PG-3
.
• Harness for short or open between battery, transfer shift high relay harness connector E46 ter-
minal 5 and transfer shift low relay harness connector E47 terminal 5.
4.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER SHIFT RELAY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer control device (actuator motor) harness
connector.
3. Remove transfer shift high relay and transfer shift low relay. Refer to TF-22, "
Location of Electrical Parts".
4. Check continuity between the following terminals.
- Transfer control unit harness connector E143 terminal 33 (A)
and transfer shift high relay harness connector E46 terminal 3
(B).
- Transfer control unit harness connector E143 terminal 42 (A)
and transfer shift low relay harness connector E47 terminal 3
(C).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK TRANSFER SHIFT RELAY GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer shift high relay and transfer shift low relay.
3. Check continuity between transfer shift high relay harness con-
nector E46 terminals 2, 4 (A), transfer shift low relay harness
connector E47 terminals 2, 4 (B) and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
6.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK-1 >> With CONSULT-II: GO TO 7.
OK-2 >> Without CONSULT-II: GO TO 8.
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.
Connector Terminal Voltage (Approx.)
E46 5 - Ground
Battery voltage
E47 5 - Ground
WDIA0311E
Continuity should exist.
WDIA0315E
Continuity should exist.
WDIA0312E

TF-76
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
7.PERFORM SELF-DIAGNOSIS (WITH CONSULT-II)
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform the self-diagnosis again.
Is the
“SHIFT ACT CIR [P1819]” displayed?
YES >> Replace transfer control unit. Refer to TF-115, "Removal and Installation".
NO >> Inspection End.
8.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II)
Without CONSULT-II1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to TF-48, "Self-Diagnosis Proce-
dure" and TF-48, "Self-Diagnosis Procedure".
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate transfer control device?
YES >> Replace transfer control unit. Refer to TF-121, "Removal and Installation".
NO >> Inspection End.
Engine Speed Signal (ECM)INFOID:0000000003532540
DIAGNOSTIC PROCEDURE
1.CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to E C - 111 , "
CONSULT-II Function (ENGINE)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 3.
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.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with ECM again. Refer to E C - 111 , "
CONSULT-II Function (ENGINE)" .
Clutch Pressure SolenoidINFOID:0000000003532541
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Monitored item Content Condition Display value
DUTY SOLENOID [%]Condition of clutch pres-
sure solenoid• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%

TROUBLE DIAGNOSIS FOR SYSTEM
TF-77
< SERVICE INFORMATION >
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Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
DIAGNOSTIC PROCEDURE
1.CHECK CLUTCH PRESSURE SIGNAL
With CONSULT-II1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “DUTY SOLENOID”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
Te r m i n a lWire
colorItem Condition Data (Approx.)
10 L/W Transfer dropping resistor• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 4 - 14V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
19 LClutch pressure solenoid
valve• Vehicle stopped
• Engine running
• A/T selector le-
ver “N” position
• Brake pedal de-
pressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever “N” position
• Brake pedal depressed4WD shift switch: 2WD 4%
4WD shift switch: AUTO 96 - 4%
4WD shift switch: 4H or
4LO4%
SDIA2718E
Connector Terminal ConditionVoltage
(Approx.)
E142 10 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO4 - 14V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
19 -
Ground• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch:
AUTO1.5 - 3V
4WD shift switch:
2WD, 4H or 4LOLess than
1V
SDIA2719E

TF-78
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND CLUTCH PRESSURE SOLENOID
VA LV E
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector, transfer terminal cord assembly harness connector
and transfer dropping resistor.
3. Check continuity between transfer control unit harness connec-
tor E142 terminal 19 and transfer terminal cord assembly har-
ness connector F56 terminal 6.
4. Check continuity between transfer dropping resistor harness
connector E135 terminal 2 and transfer terminal cord assembly
harness connector F56 terminal 6.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER DROPPING RESISTOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer dropping resistor harness connector.
3. Check continuity between transfer control unit harness connec-
tor E142 terminal 10 and transfer dropping resistor harness con-
nector E135 terminal 1.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check continuity between transfer terminal cord assembly har-
ness connector F56 terminal 19 and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors. Continuity should exist.
SDIA2720E
Continuity should exist.
SDIA2721E
Continuity should exist.
SDIA2722E
Continuity should exist.
SDIA2723E