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 N POSI SW TF.

      Condition		Display value
      Vehicle stopped Engine running A/T selector lever N position Brake pedal depressed	4WD shift switch: 2WD, AUTO or 4H	OFF
      	4WD shift switch: 4H to 4LO (While actuator motor is operating.)	OFF → ON
      	4WD shift switch: 4LO to 4H (While actuator motor is operating.)	ON → OFF
      	4WD shift switch: 4LO	ON

   Without CONSULT 

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

      Connector	Terminal (Wire color)	Condition		Voltage (Approx.)
      E143	25 - Ground	Vehicle stopped Engine running A/T selector lever N position Brake pedal depressed	4WD shift switch: 2WD, AUTO or 4H	Battery voltage
      			4WD shift switch: 4H to 4LO (While actuator motor is operating.)	Battery voltage → 0V
      			4WD shift switch: 4LO to 4H (While actuator motor is operating.)	0V → Battery voltage
      			4WD shift switch: 4LO	0V

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

      Courtesy of NISSAN NORTH AMERICA, INC.

      Are inspection results normal? 

      YES: GO TO  5.

      NO: GO TO 2.

2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND NEUTRAL-4LO SWITCH 
   1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
   2. Disconnect transfer control unit harness connector and the neutral-4LO switch harness connector.
   3. Check continuity between transfer control unit harness connector E143 terminal 25 and neutral-4LO switch harness connector F60 terminal 13.

      Continuity should exist. 

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

      Are inspection results normal? 

      YES: GO TO 3.

      NO: Repair or replace damaged parts.

      Fig 2: Checking Continuity Between Transfer Control Unit Harness Connector E143 Terminal 25 And Neutral-4LO Switch Harness Connector F60 Terminal 13

      Courtesy of NISSAN NORTH AMERICA, INC.
3. CHECK GROUND CIRCUIT 
   1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
   2. Disconnect neutral-4LO switch harness connector.
   3. Check continuity between neutral-4LO switch harness connector F60 terminal 12 and ground.

      Continuity should exist. 

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

      Are inspection results normal? 

      YES: GO TO 4.

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

      Fig 3: Checking Continuity Between Neutral-4LO Switch Harness Connector F60 Terminal 12 And Ground

      Courtesy of NISSAN NORTH AMERICA, INC.
4. CHECK 4LO SWITCH 
   1. Turn ignition switch OFF.
   2. Disconnect neutral-4LO switch harness connector.
   3. Remove neutral-4LO switch.
   4. Push and release neutral-4LO switch and check continuity between neutral-4LO switch terminals 12 and 13.

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

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

      Courtesy of NISSAN NORTH AMERICA, INC.

      Are inspection results normal? 

      YES: GO TO 5.

      NO: Replace neutral-4LO switch. Refer to "COMPONENT PARTS LOCATION ".

5. CHECK TRANSFER CONTROL UNIT 

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

   Are 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.

   Are inspection results normal? 

   YES: Inspection End.

   NO: Replace transfer control unit. Refer to "REMOVAL AND INSTALLATION ".