Diagnostic Procedure

WARNING: This page is about a different car, the 2006 Nissan Xterra. However, it is still accessible from the selected car via links, so may be relevant.

CHECK POWER SUPPLY

Turn ignition switch "OFF". (Stay for at least 5 seconds.)
Disconnect transfer control unit harness connector.

Check voltage between transfer control unit harness connector terminals and ground.

TRANSFER CONTROL UNIT CONNECTOR TERMINALS AND GROUND VOLTAGE

Connector	Terminal	Voltage (Approx.)
M152	19 - Ground	Battery voltage
M152	25 - Ground	0V
M153	40 - Ground	Battery Voltage
	44 - Ground	0V
	45 - Ground	0V

Fig 1: Identifying Voltage Between Transfer Control Unit Harness Connector Terminals And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

Turn ignition switch "ON". (Do not start engine.)
Check voltage between transfer control unit harness connector terminals and ground.

TRANSFER CONTROL UNIT CONNECTOR TERMINALS AND GROUND VOLTAGE

Connector	Terminal	Voltage (Approx.)
M152	19 - Ground	Battery voltage
M152	25 - Ground
M153	40 - Ground
	44 - Ground
	45 - Ground

Fig 2: Identifying Voltage Between Transfer Control Unit Connector Terminals And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2.

NG: Check the following. If any items are damaged, repair or replace damaged parts.

40A fusible link (No. j, located in the fuse and fusible link box). Refer to "POWER SUPPLY ROUTING CIRCUIT ".
10A fuses [No. 21, located in the fuse block (J/B) and Nos. 57 and 58 located in the fuse and relay box]. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
Harness for short or open between battery and transfer control unit harness connector M152 terminal 19.
Harness for short or open between battery and transfer shut off relay 2 harness connector E157 terminal 1 and 3.
Harness for short or open between battery and transfer shut off relay 1 harness connector E156 terminal 3.
Harness for short or open between ignition switch and transfer control unit harness connector M152 terminal 25.
Harness for short or open between ignition switch and transfer shut off relay 1 harness connector E156 terminal 1.
Harness for short or open between transfer shut off relay 2 harness connector E157 terminal 5 and transfer control unit harness connector M153 terminals 44, 45.
Harness for short or open between transfer shut off relay 1 harness connector E156 terminal 5 and transfer control unit harness connector M153 terminals 44, 45.
Harness for short or open between transfer shut off relay 2 harness connector E157 terminal 2 and transfer control unit harness connector M153 terminal 40.
Harness for open between transfer shut off relay 1 harness connector E156 terminal 2 and ground.
Battery and ignition switch. Refer to "POWER SUPPLY ROUTING CIRCUIT ".
Transfer shut off relay 1, 2. Refer to "COMPONENT INSPECTION ".

CHECK GROUND CIRCUIT
1. Turn ignition switch "OFF".
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connector M152 terminals 6 and 18, and M153 terminal 32 and ground.
Continuity should exist .

Also check harness for short to power.

OK or NG

OK: GO TO 3.

NG: Repair open circuit or short to power in harness or connectors.

Fig 3: Identifying Continuity Between Transfer Control Unit Connector M152 Terminals And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to "TRANSFER CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES ".

OK or NG

OK: GO TO 4.

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.
CHECK DTC
Perform the self-diagnosis, after driving vehicle for a while.

OK or NG

OK: Inspection End.

NG: Replace transfer control unit. Refer to "REMOVAL AND INSTALLATION ".