INFINITI QX4 2005 Factory Service Manual

TF-78
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK ACTUATOR POSITION SWITCH SIGNAL
With CONSULT-II
1. 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.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
Monitored item Condition Display value
SHIFT POS SW1

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

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch: 4H,
AUTO or 2WDON
4WD shift switch: 4LO OFF
ConnectorTerminal
(Wire
color)ConditionVoltage
(Approx.)
E14327 (W/L)
- Ground

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: 4H,
AUTO or 2WD0V
4WD shift switch: 4LOBattery
voltage
44 (LG/B)
- Ground

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD shift switch: 4LO 0V
4WD shift switch:
2WD, AUTO or 4HBattery
voltage
SDIA2714E
SDIA2715E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-79
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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 (W/L)
and transfer control device (actuator position switch) harness
connector F58 terminal 23 (W/L).
–Transfer control unit harness connector E143 terminal 44 (LG/B)
and transfer control device (actuator position switch) harness
connector F58 terminal 20 (LG/B).
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 (B) 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-138, "
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.
OK or NG
YES >> GO TO 5.
NO >> Replace transfer control device (actuator motor). Refer to TF-138, "
Removal and Installation" . Continuity should exist.
SDIA2716E
Continuity should exist.
SDIA2717E
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

TF-80
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-36, "
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 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-138, "
Removal and Installation" .
COMPONENT INSPECTION
1. Remove transfer control device. Refer to TF-138, "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-138, "
Removal and Installation" .
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-81
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Transfer Control DeviceEDS002IE
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
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.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
operating.)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
operating.)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
lever “N” position

Brake pedal
depressed4WD 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
lever “N” position

Brake pedal
depressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V

TF-82
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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.
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-4, "POWER SUPPLY
ROUTING CIRCUIT" .

Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 1 (G).

Harness for short or open between transfer shut off relay harness connector E69 terminal 2
(SB) and transfer control unit harness connector E143 terminal 30 (SB).

Harness for short or open between battery and transfer shut off relay harness connector E69
terminal 3 (G).

Harness for short or open between transfer shut off relay harness connector E69 terminal 5 (Y/
R) and transfer control unit harness connector E142 terminal 22 (Y/R).

Transfer shut off relay. Refer to TF-57, "COMPONENT INSPECTION" .
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
0V
22 (Y/R) - Ground
E143 30 (SB) - Ground Battery voltage
SDIA2834E
Connector Terminal (Wire color) Voltage (Approx.)
E14216 (Y/R) - Ground
Battery voltage
22 (Y/R) - Ground
E143 30 (SB) - Ground 0V
SDIA2835E

TROUBLE DIAGNOSIS FOR SYSTEM
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Revision: October 20052005 QX56
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 (B), 6 (B), E143 terminal 45 (B) 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 (R), transfer shift low relay harness connector
E47 terminal 5 (R) and ground.
4. Turn ignition switch “ON”. (Do not start engine.)
5. Check voltage between transfer shift high relay harness connec-
tor E46 terminal 5 (R), transfer shift low relay harness connector
E47 terminal 5 (R) 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-4, "POWER SUPPLY ROUTING
CIRCUIT" .

Harness for short or open between battery, transfer shift high relay harness connector E46 ter-
minal 5 (R) and transfer shift low relay harness connector E47 terminal 5 (R). Continuity should exist.
SDIA2691E
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2707E
Connector Terminal (Wire color) Voltage (Approx.)
E46 5 (R) - Ground
Battery voltage
E47 5 (R) - Ground
SDIA2706E

TF-84
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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 (R/L)
and transfer shift high relay harness connector E46 terminal 3
(R/L).
–Transfer control unit harness connector E143 terminal 42 (P/G)
and transfer shift low relay harness connector E47 terminal 3 (P/
G).
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 1 (B/W), 4 (B), transfer shift low relay har-
ness connector E47 terminal 1 (B/W), 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-54, "
TRANSFER CONTROL UNIT TERMINALS
AND REFERENCE 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. Continuity should exist.
SDIA2712E
Continuity should exist.
SDIA2708E

TROUBLE DIAGNOSIS FOR SYSTEM
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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-132, "Removal and Installation" .
NO >> Inspection End.
8. PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-II)
Without CONSULT-II
1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to TF-50, "
SELF-DIAGNOSTIC
PROCEDURE (WITHOUT CONSULT-II)" and TF-53, "ERASE SELF-DIAGNOSIS" .
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate transfer control device?
YES >> Replace transfer control unit. Refer to TF-132, "Removal and Installation" .
NO >> Inspection End.
Engine Speed Signal (ECM)EDS0 02 IF
DIAGNOSTIC PROCEDURE
1. CHECK DTC WITH ECM
Perform self-diagnosis with ECM. Refer to EC-130, "
SELF-DIAG RESULTS MODE" .
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-36, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
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 EC-130, "
SELF-DIAG RESULTS MODE" .

TF-86
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
Clutch Pressure SolenoidEDS002IG
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
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.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%
Te r m i n a lWire
colorItem Condition Data (Approx.)
10 L/W Transfer dropping resistor

Vehicle stopped

Engine running

A/T selector
lever “N” position

Brake pedal
depressed4WD 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
lever “N” position

Brake pedal
depressed4WD shift switch: AUTO 1.5 - 3V
4WD shift switch: 2WD, 4H or 4LO Less than 1V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-87
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK CLUTCH PRESSURE SIGNAL
With CONSULT-II
1. 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.
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
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E142 10 (L/W)
- Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
AUTO4 - 14V
4WD shift switch:
2WD, 4H or 4LOLess
than 1V
19 (L) -
Ground

Vehicle stopped

Engine running

A/T selector lever
“N” position

Brake pedal
depressed4WD shift switch:
AUTO1.5 - 3V
4WD shift switch:
2WD, 4H or 4LOLess
than 1V
SDIA2719E