2005 INFINITI QX4 ignition

TROUBLE DIAGNOSIS FOR SYSTEM
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Revision: October 20052005 QX56
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-88
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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 (L) and transfer terminal cord assembly
harness connector F56 terminal 6 (L).
4. Check continuity between transfer dropping resistor harness
connector E135 terminal 2 (L) and transfer terminal cord assem-
bly harness connector F56 terminal 6 (L).
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 (L/W) and transfer dropping resistor har-
ness connector E135 terminal 1 (L/W).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.Continuity should exist.
SDIA2720E
Continuity should exist.
SDIA2721E
Continuity should exist.
SDIA2722E

TROUBLE DIAGNOSIS FOR SYSTEM
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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 (B) 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.
5. CHECK CLUTCH PRESSURE SOLENOID
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 6 and 19.
OK or NG
OK >> GO TO 6.
NG >> Replace clutch pressure solenoid. Refer to TF-22,
"Location of Electrical Parts" .
6. CHECK TRANSFER DROPPING RESISTOR
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer dropping resistor harness connector. Refer to TF-22, "
Location of Electrical Parts" .
3. Check resistance between transfer dropping resistor terminals 1
and 2.
OK or NG
OK >> GO TO 7.
NG >> Replace transfer dropping resistor. Refer to TF-22,
"Location of Electrical Parts" .
7. 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 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.
SDIA2723E
6 - 19 : Approx. 3.0 - 3.4 Ω
WDIA0225E
1 - 2 : Approx. 11.2 - 12.8 Ω
SDIA2725E

TF-90
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
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" .
COMPONENT INSPECTION
Clutch Pressure Solenoid
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 6 and 19.
4. If NG, replace clutch pressure solenoid. Refer to TF-22, "
Loca-
tion of Electrical Parts" .
Transfer Dropping Resistor
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer dropping resistor harness connector.
3. Check resistance between transfer dropping resistor terminals 1
and 2.
4. If NG, replace transfer dropping resistor. Refer to TF-22, "
Loca-
tion of Electrical Parts" . 6 - 19 : Approx. 3.0 - 3.4 Ω
WDIA0225E
1 - 2 : Approx. 11.2 - 12.8 Ω
SDIA2725E

TROUBLE DIAGNOSIS FOR SYSTEM
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3. CHECK 4WD SHIFT SWITCH SIGNAL
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check voltage between transfer control unit harness connector
terminals and ground.
OK or NG
OK >> GO TO 4.
NG >> Check 4WD shift switch. Refer to TF-66, "
COMPONENT INSPECTION" .
4. CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER TERMINAL CORD ASSEMBLY
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector and transfer terminal cord assembly harness connector.
3. Check continuity between 4WD shift switch harness connector
M141 terminal 4 (G/R) and transfer terminal cord assembly har-
ness connector F56 terminal 5 (G/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 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 transfer control unit harness connec-
tor E142 terminal 1 (GR) and transfer terminal cord assembly
harness connector F56 terminal 4 (GR).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
ConnectorTe r m i n a l
(Wire color)ConditionVoltage
(Approx.)
M1414 (G/R) -
ground4WD shift switch: AUTO, 4H or 4LO Battery voltage
4WD shift switch: 2WD 0V
SDIA2729E
Continuity should exist.
SDIA2731E
Continuity should exist.
SDIA2732E

TF-94
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
6. CHECK 2-4WD SOLENOID
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 4 and 5.
OK or NG
OK >> GO TO 7.
NG >> 2-4WD solenoid is malfunctioning. Refer to TF-22,
"Location of Electrical Parts" .
7. 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 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" .
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 ter-
minals 4 and 5.
4. If NG, replace the 2-4WD solenoid. Refer to TF-22, "
Location of
Electrical Parts" . 4 - 5 : Approx. 22.8 - 25.2 Ω
WDIA0187E
4 - 5 : Approx. 22.8 - 25.2 Ω
WDIA0187E

TROUBLE DIAGNOSIS FOR SYSTEM
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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