Symptom 9. 4WD System Does Not Operate

WARNING: This page is about a different car, the 2003 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: The vehicle cannot be put into 4WD mode. (Hydraulic system failure)

CHECK INPUT SIGNAL
With CONSULT-II
1. Select "ECU INPUT SIGNALS" in Data Monitor.
2. Read out the ON/OFF status of "CLUTCH PRES SW".
  
  Fig 1: Checking Input Signal With CONSULT-II
  Courtesy of NISSAN MOTOR CO., U.S.A.
Without CONSULT-II

Check voltage between transfer control unit harness connector terminal 34 and body ground. Refer to "TRANSFER CONTROL UNIT INSPECTION TABLE ", "TROUBLE DIAGNOSIS - GENERAL DESCRIPTION".

OK or NG
1. OK:
  1. Check transfer fluid level.
  2. Disassemble transfer unit and check the following.
    - Transfer motor
    - Main oil pump assembly
    - Sub-oil pump assembly
    - Oil strainer
    - Control valve assembly
    - 2-4WD shift solenoid valve
    - Oil filter element
    - Lip seal
    - Strainer O-ring
    - Main oil pump drive gear
    - Seal ring
    - D-ring
    - Clutch piston
    - Clutch assembly
2. NG: GO TO 2.
CHECK CLUTCH PRESSURE CIRCUIT
Check clutch pressure switch circuit. Refer to "DIAGNOSTIC PROCEDURE ", "CLUTCH PRESSURE SWITCH".

OK or NG
1. OK: GO TO 3.
2. NG: Check, repair or replace faulty parts.
CHECK PROCEDURES FROM THE BEGINNING
Check again.

OK or NG
1. OK: INSPECTION END
2. NG: Recheck each connector's pin terminals for damage or loose connection.