2005 INFINITI QX4 relay

TROUBLE DIAGNOSIS FOR SYSTEM
TF-83
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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
TF-95
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Revision: October 20052005 QX56
Transfer MotorEDS0 02 II
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
Monitored item Content Condition Display value
MOTOR RELAY [ON/
OFF]Condition of transfer motor
relay

Accelerator pedal
depressed

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
selector lever “P” or “N”
position)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
(Except for A/T selector
lever “P” position)ON
MOTOR RELAY MON
[ON/OFF]Check signal for transfer
control unit signal output

Accelerator pedal
depressed

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
selector lever “P” or “N”
position)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
(Except for A/T selector
lever “P” position)ON

TF-96
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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.Te r m i n a lWire
colorItem Condition Data (Approx.)
14 LG Transfer motor relay

Accelerator
pedal depressed

Vehicle stopped

Engine running

Brake pedal
depressed4WD shift switch: 2WD Battery 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
41 R Transfer motor relay monitor

Accelerator
pedal depressed

Vehicle stopped

Engine running

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

TROUBLE DIAGNOSIS FOR SYSTEM
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Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK TRANSFER MOTOR RELAY 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 “MOTOR RELAY” and “MOTOR RELAY
MON”.
Without CONSULT-II
1. Start engine.
Monitored
itemConditionDisplay value
(Approx.)
MOTOR
RELAY

Accelerator
pedal depressed

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 selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON
MOTOR
RELAY
MON

Accelerator
pedal depressed

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 selector
lever “P” or “N” position)ON
4WD shift switch: 4H (A/T
selector lever “P” position)OFF
("ON" for
approx. 2 sec.
after shifting to
“P”.)
4WD shift switch: 4H (Except
for A/T selector lever “P” posi-
tion)ON
SDIA2734E

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

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