Diagnosis Procedure

Regarding Wiring Diagram information, refer to "WIRING DIAGRAM ".

1. CHECK 4LO POSITION SWITCH SIGNAL

   With CONSULT 

   1. Start engine.
   2. Select "DATA MONITOR" mode for "ALL MODE AWD/4WD" with CONSULT.
   3. Read out the value of "4L POSI SW".

      Condition		Display value
      Vehicle stopped Engine running A/T selector lever "N" position Brake pedal depressed	4WD shift switch: 4LO	ON
      	Except the above	OFF

   Without CONSULT 

   1. Start engine.
   2. Check voltage between transfer control unit harness connector terminal and ground.

      Connector	Terminal	Condition		Voltage (Approx.)
      M165	24 - Ground	Vehicle stopped Engine running A/T selector lever "N" position Brake pedal depressed	4WD shift switch: 4LO	0V
      			Except the above	Battery voltage

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

      Courtesy of NISSAN NORTH AMERICA, INC.

      Are the inspection results normal? 

      YES: GO TO  5.

      NO: GO TO 2.

2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND 4LO SWITCH
   1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
   2. Disconnect transfer control unit harness connector and the 4LO switch harness connector.
   3. Check continuity between transfer control unit harness connector M165 terminal 24 and 4LO switch harness connector F74 terminal 13.

      Continuity should exist  .

      Fig 2: Checking Continuity Between Transfer Control Unit Harness Connector M165 Terminal 24 And 4Lo Switch Harness Connector F74 Terminal 13

      Courtesy of NISSAN NORTH AMERICA, INC.

      Also check harness for short to ground and short to power.

      Is there continuity? 

      YES: GO TO 3.

      NO: Repair or replace damaged parts.

3. CHECK GROUND CIRCUIT
   1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
   2. Disconnect 4LO switch harness connector.
   3. Check continuity between 4LO switch harness connector F74 terminal 12 and ground.

      Continuity should exist  .

      Fig 3: Checking Continuity Between 4LO Switch Connector F74 Terminal 12 And Ground

      Courtesy of NISSAN NORTH AMERICA, INC.

      Also check harness for short to power.

      Is there continuity? 

      YES: GO TO 4.

      NO: Repair open circuit or short to power in harness or connectors.

4. CHECK 4LO SWITCH
   1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
   2. Disconnect 4LO switch harness connector.
   3. Remove 4LO switch. Refer to "COMPONENT PARTS LOCATION ".
   4. Push and release 4LO switch and check continuity between 4LO switch terminals 12 and 13.

      Terminal	Condition	Continuity
      12 - 13	Push 4LO switch	Yes
      	Release 4LO switch	No

      Fig 4: Checking Continuity Between 4LO Switch Terminals 12 And 13

      Courtesy of NISSAN NORTH AMERICA, INC.

      Are the inspection results normal? 

      YES: GO TO 5.

      NO: Replace 4LO switch.

5. CHECK TRANSFER CONTROL UNIT

   Check transfer control unit input/output signal. Refer to "REFERENCE VALUE ".

   Are the inspection results normal? 

   YES: GO TO 6.

   NO: Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

6. CHECK DTC

   Drive the vehicle and then perform self-diagnosis.

   Is DTC P1810 displayed? 

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

   NO: Inspection End.