Diagnostic Procedure

1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector terminals and ground.
   TERMINAL WIRE COLOR ITEM CONDITION
   
   

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

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

   Courtesy of NISSAN MOTOR CO., U.S.A.
4. Turn ignition switch "ON". (Do not start engine.)
5. Check voltage between transfer control unit harness connector terminals and ground.
   TERMINAL CONNECTOR VOLTAGE
   
   

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

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

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

OK or NG 

1. OK: GO TO 2.
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 ".

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 

1. OK: GO TO 3.
2. NG: Repair open circuit or short to power in harness or connectors.
   Fig 3: Checking Continuity Between Transfer Control Unit Harness Connector M152 Terminals 6 And 18 And M153 Terminal 32 And Ground

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

Check transfer control unit input/output signal. Refer to "TRANSFER CONTROL UNIT INPUT/OUTPUT SIGNAL REFERENCE VALUES ".

OK or NG 

1. OK: GO TO 4.
2. 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.

Perform the self-diagnosis after driving vehicle.

OK or NG 

1. OK: Inspection End.
2. NG: Replace transfer control unit. Refer to "REMOVAL AND INSTALLATION ".