Diagnostic Procedure

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

CHECK 4LO POSITION SWITCH SIGNAL

With CONSULT-II

Start engine.
Select "DATA MONITOR" mode for "ALL MODE AWD/4WD" with CONSULT-II.

Read out the value of "N POSI SW TF".

DISPLAY VALUE CONDITION

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

Fig 1: Identifying CONSULT-II Display - DATA MONITOR

Without CONSULT-II

Start engine.

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

CONNECTOR TERMINAL VOLTAGE REFERENCE

Connector	Terminal	Condition		Voltage (Approx.)
M153	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 2: Checking Voltage Between Transfer Control Unit Harness Connector Terminal And Ground

OK or NG

OK: GO TO 5.

NG: GO TO 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 M153 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.
OK or NG

OK: GO TO 3.

NG: Repair or replace damaged parts.

Fig 3: Checking Continuity Between Transfer Control Unit Connector Terminal And Neutral-4LO Switch Connector Terminal
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 power.
  
  Fig 4: Checking Continuity Between Neutral-4LO Switch Harness Connector F60 Terminal 12 And Ground
OK or NG

OK: GO TO 4.

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

CHECK 4LO SWITCH

Turn ignition switch "OFF".
Disconnect neutral-4LO switch harness connector.
Remove neutral-4LO switch. Refer to "LOCATION OF ELECTRICAL PARTS ".

Push and release neutral-4LO switch and check continuity between neutral-4LO switch terminals 12 and 13.

CONNECTOR TERMINAL CONTINUITY REFERENCE

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

Fig 5: Checking Continuity Between Neutral-4LO Switch Terminals 12 And 13

OK or NG

OK: GO TO 5.

NG: Replace neutral-4LO switch. Refer to "LOCATION OF ELECTRICAL PARTS ".

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 6.

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 a vehicle for a while.

OK or NG

OK: Inspection End.

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