INFINITI QX4 2005 Factory Service Manual

TF-98
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
ConnectorTe r m i n a l
(Wire
color)Condition Voltage (Approx.)
E142 14 (LG) -
Ground

Accelera-
tor pedal
depressed

Vehicle
stopped

Engine
running

Brake
pedal
depressed4WD shift switch:
2WDBattery voltage
4WD shift switch:
AUTO or 4LO (A/T
selector lever “P” or
“N” position)Battery voltage
(0V for approx. 2
sec. after shifting
to “P” and “N”.)
4WD shift switch:
AUTO or 4LO
(Except for A/T
selector lever “P” or
“N” position)0V
4WD shift switch:
4H (A/T selector
lever “P” position)Battery voltage
(0V for approx. 2
sec. after shifting
to “P”.)
4WD shift switch:
4H (Except for A/T
selector lever “P”
position)0V
E143 41 (R) -
Ground

Accelera-
tor pedal
depressed

Vehicle
stopped

Engine
running

Brake
pedal
depressed4WD shift switch:
2WD0V
4WD shift switch:
AUTO or 4LO (A/T
selector lever “P” or
“N” position)0V
(Battery voltage
for approx. 2 sec.
after shifting to
“P” and “N”.)
4WD shift switch:
AUTO or 4LO
(Except for A/T
selector lever “P” or
“N” position)Battery voltage
4WD shift switch:
4H (A/T selector
lever “P” position)0V
(Battery voltage
for approx. 2 sec.
after shifting to
“P”.)
4WD shift switch:
4H (Except for A/T
selector lever “P”
position)Battery voltage
SDIA2735E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-99
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Revision: October 20052005 QX56
2. CHECK TRANSFER MOTOR RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Disconnect transfer motor relay.
4. Check voltage between transfer motor relay harness connector
terminals and ground.
5. Turn ignition switch “ON”. (Do not start engine.)
6. Check voltage between transfer motor relay harness connector
terminals and ground.
OK or NG
OK >> GO TO 3.
NG >> Check the following. If any items are damaged, repair or
replace damaged parts.

20A fuse No. 58 located in the fuse and relay box. Refer to PG-4, "POWER SUPPLY ROUTING
CIRCUIT" .

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 motor relay harness connector E154
terminal 5 (G/R).

Harness for short or open between transfer shut off relay harness connector E69 terminal 5 (Y/
R) and transfer motor relay harness connector E153 terminal 2 (Y/R).

Battery and ignition switch. Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .
3. CHECK TRANSFER MOTOR RELAY
1. Turn ignition switch “OFF”.
2. Remove transfer motor relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Apply 12V direct current between transfer motor relay terminals
1 and 2.
4. Check continuity between relay terminals 3 and 5.
OK or NG
OK >> GO TO 4.
NG >> Replace the transfer motor relay.
Connector Terminal (Wire color) Voltage (Approx.)
E153 2 (Y/R) - Ground 0V
E154 5 (G/R) - Ground Battery voltage
WDIA0169E
Connector Terminal (Wire color) Voltage (Approx.)
E153 2 (Y/R) - Ground
Battery voltage
E154 5 (G/R) - Ground
WDIA0170E
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
LDIA0098E

TF-100
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
4. CHECK TRANSFER MOTOR CONTROL CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer motor relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Disconnect transfer control unit harness connector and transfer motor.
4. Check continuity between the following terminals.
–Transfer control unit harness connector E142 terminal 14 (LG)
and transfer motor relay harness connector E153 terminal 1
(LG).
–Transfer control unit harness connector E142 terminal 41 (R)
and transfer motor relay harness connector E154 terminal 3 (R).
–Transfer control unit harness connector E142 terminal 41 (R)
and transfer motor harness connector F57 terminal 14 (R).
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 MOTOR GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer motor harness connector.
3. Check continuity between transfer motor harness connector F57
terminal 15 (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.
SDIA2738E
Continuity should exist.
WDIA0143E
Continuity should exist.
SDIA2740E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-101
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Revision: October 20052005 QX56
6. CHECK TRANSFER MOTOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer motor harness connector.
3. Apply 12V direct current between transfer motor terminals 14
and 15.
Does transfer motor operate?
YES >> GO TO 7.
NO >> Replace transfer motor. Refer to TF-140, "
Removal and
Installation" .
7. 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 >> 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.
8. CHECK DTC
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-132, "
Removal and Installation" .
LDIA0097E

TF-102
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
COMPONENT INSPECTION
Transfer Motor Relay
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer motor relay. Refer to TF-22, "
Location of Electrical Parts" .
3. Apply 12V direct current between transfer motor relay terminals
1 and 2.
4. Check continuity between relay terminals 3 and 5.
5. If NG, replace transfer motor relay. Refer to TF-22, "
Location of
Electrical Parts" .
Transfer Motor
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove transfer motor. Refer to TF-140, "
Removal and Installation" .
3. Apply 12V direct current between transfer motor terminals 14
and 15.
4. If transfer motor does not operate, replace transfer motor. Refer
to TF-140, "
Removal and Installation" .
Transfer Fluid TemperatureEDS002IJ
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.Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
LDIA0098E
LDIA0097E
Monitored item [Unit] Content ConditionDisplay value
(Approx.)
FLUID TEMP SE [V]Condition of transfer fluid
temperatureTransfer fluid temperature approx. 20 - 80°C (68 -
176°F)1.1 - 0.3V
Te r m i n a lWire
colorItem Condition Data (Approx.)
28 B/G Sensor ground Always 0V
31 GTransfer fluid temperature
sensorIgnition switch: ONTransfer fluid temperature approx. 20°C
(68°F)1.1V
Transfer fluid temperature approx. 80°C
(176°F)0.3V

TROUBLE DIAGNOSIS FOR SYSTEM
TF-103
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER FLUID TEMPERATURE SENSOR 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 “FLUID TEMP SE”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND TRANSFER TERMINAL CORD
ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and transfer terminal cord assembly harness connec-
tor.
3. Check continuity between the following terminals.
–Transfer control unit harness connector E143 terminal 28 (B/G)
and transfer terminal cord assembly harness connector F56 ter-
minal 3 (B/G).
–Transfer control unit harness connector E143 terminal 31 (G)
and transfer terminal cord assembly harness connector F56 ter-
minal 2 (G).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
ConditionDisplay value
(Approx.)
Transfer fluid temperature approx. 20 - 80°C (68 - 176°F) 1.1 - 0.3V
SDIA2741E
ConnectorTe r m i n a l
(Wire
color)ConditionData
(Approx.)
E14328 (B/G)
- GroundAlways 0V
31 (G) -
GroundIgnition switch:
ONTransfer fluid temperature
approx. 20°C (68°F)1.1V
Transfer fluid temperature
approx. 80°C (176°F)0.3V
SDIA2742E
Continuity should exist.
SDIA2743E

TF-104
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
3. CHECK TRANSFER FLUID TEMPERATURE SENSOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly ter-
minals 2 and 3.
OK or NG
OK >> GO TO 4.
NG >> Replace transfer fluid temperature sensor. Refer to TF-
22, "Location of Electrical Parts" .
4. 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 >> 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 DTC
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-132, "
Removal and Installation" .
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer terminal cord assembly harness connector.
3. Check resistance between transfer terminal cord assembly har-
ness connector F56 terminals 2 and 3.
4. If NG, replace the transfer fluid temperature sensor. Refer to TF-
22, "Location of Electrical Parts" .
Temperature °C (°F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
WDIA0188E
Temperature °C (°F) Resistance (Approx.)
20 (68) 2.5 kΩ
80 (176) 0.3 kΩ
WDIA0188E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-105
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Revision: October 20052005 QX56
Clutch Pressure SwitchEDS002IK
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
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
operating.)ON

Vehicle stopped

Engine running

4WD shift switch: 2WD (“Wait” function is not oper-
ating.)OFF
Te r m i n a lWire
colorItem Condition Data (Approx.)
34 BR Clutch pressure switch

Vehicle stopped

Engine running

A/T selector
lever “D” position4WD shift switch: AUTO or 4H (“Wait”
function is not operating.)0V

Vehicle stopped

Engine running4WD shift switch: 2WD (“Wait” function is
not operating.)Battery voltage

TF-106
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK CLUTCH PRESSURE SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out ON/OFF switching action of the “CL PRES SW” while
operating 4WD shift switch.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND CLUTCH PRESSURE SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the transfer terminal cord assembly harness con-
nector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 34 (BR) and transfer terminal cord assembly
harness connector F56 terminal 7 (BR)
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value

Ignition switch: ON

A/T selector lever “D”
position4WD shift switch: AUTO or 4H
(“Wait” function is not operating.)ON
Ignition switch: ON4WD shift switch: 2WD (“Wait”
function is not operating.)OFF
ConnectorTerminal
(Wire
color)ConditionVoltage
(Approx.)
E14334 (BR) -
Ground

Ignition switch: ON

A/T selector lever
“D” position4WD shift switch:
AUTO or 4H
(“Wait” function is
not operating.)0V
Ignition switch: ON4WD shift switch:
2WD (“Wait” func-
tion is not operat-
ing.)Battery
voltage
WDIA0141E
SDIA2746E
Continuity should exist.
SDIA2747E

TROUBLE DIAGNOSIS FOR SYSTEM
TF-107
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Revision: October 20052005 QX56
3. 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 >> GO TO 4.
NG >> Check transfer control unit pin terminals for damage or loose connection with the harness connec-
tor. If any items are damaged, repair or replace damaged parts.
4. CHECK CLUTCH PRESSURE SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release clutch pressure switch and check continuity
between transfer terminal cord assembly terminal 7 and ground.
OK or NG
OK >> GO TO 5.
NG >> Replace clutch pressure switch. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
5. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> GO TO 6.
NG >> Replace transfer control unit. Refer to TF-132, "
Removal and Installation" .
6. CRUISE TEST
Perform cruise test. Refer to TF-34, "
CRUISE TEST" .
OK or NG
OK >> Inspection End.
NG >> Perform the applicable trouble diagnosis.
COMPONENT INSPECTION
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Remove clutch pressure switch. Refer to TF-22, "
Location of Electrical Parts" .
3. Push and release clutch pressure switch and check continuity
between transfer terminal cord assembly terminal 7 and ground.
4. If NG, replace the clutch pressure switch. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
Terminal Condition Continuity
7 -
GroundPush clutch pressure switch Yes
Release clutch pressure switch No
WDIA0171E
Terminal Condition Continuity
7 - GroundPush clutch pressure switch Yes
Release clutch pressure switch No
WDIA0171E