Diagnostic Procedure

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.

SHIFT ACTUATOR CIRCUIT
Refer to "TRANSFER SHIFT RELAY (HIGH & LOW) ", "COMPONENT INSPECTION" and "ACTUATOR & ACTUATOR POSITION SWITCH ", "COMPONENT INSPECTION".

OK or NG
1. OK: GO TO 2.
2. NG: Repair or replace transfer shift relay and actuator and actuator position switch.
CHECK POWER SOURCE OF TRANSFER SHIFT (HI & LOW) RELAY

Fig 1: Transfer Shift (HI And LOW) Relay Circuit Diagram
Courtesy of NISSAN MOTOR CO., U.S.A.
1. Disconnect transfer control device terminal.
2. Turn ignition switch to "ON" (Do not start engine).
3. Check voltage between transfer shift HI and LOW relay terminal 5 and body ground.
  Voltage: Battery voltage
  
  Fig 2: Checking Voltage Between Transfer Shift HI And LOW Relay Terminal And Body Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 3.
2. NG: Check the following.
  - Continuity between ignition switch and transfer shift HI & LOW relays
  - Check ground circuit between transfer shift HI & LOW relays and body ground.
  - Ignition switch and No. 3 fuse (20A)
CHECK POWER SOURCE OF TRANSFER CONTROL DEVICE
1. Disconnect transfer control device terminal.
2. Turn ignition switch to "ON". (Do not start engine.)
3. Turn 4WD shift switch from "4H" to "4LO" (or from "4LO" to "4H").
4. Check voltage between transfer control device terminal 3 (or 4) and body ground.
  Voltage: Battery voltage
  
  Fig 3: Checking Transfer Control Device Power Source
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG:
  Check the following.
  - Harness and connector from transfer shift HI and LOW relays to transfer control device harness terminal
  - Ground circuit between transfer control device and body ground.
CHECK INPUT SIGNAL
1. WITH CONSULT-II: GO TO 5.
2. WITHOUT CONSULT-II: GO TO 6.
CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine (idling).
2. Select "SELF-DIAG RESULTS" in Select Diag Mode.
3. Read out self-diagnostic result.
  
  Fig 4: Identifying Transfer Shift HI And LOW Relay Connection With Transfer Control Unit
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 5: CONSULT-II - Self Diag Results Display
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: GO TO 7.
CHECK INPUT SIGNAL
Without CONSULT-II
1. Start engine (idling).
2. Check voltage between transfer control unit harness connector terminal 4 (or 13) and body ground while 4WD shift switch is set from 4H to 4LO (or from 4LO to 4H).
  
  Fig 6: Checking Voltage Between Transfer Control Unit Harness Connector Terminal And Body Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Result
  
  Fig 7: Terminal No. And Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: GO TO 7.
CHECK HARNESS CONTINUITY BETWEEN TRANSFER CONTROL UNIT AND TRANSFER CONTROL DEVICE
OK or NG
1. OK: GO TO 8.
2. NG: Repair and replace harness connector between transfer control unit and transfer control device.
PERFORM SELF-DIAGNOSIS AGAIN
After driving for a while, perform self-diagnosis again. Refer to "TROUBLE DIAGNOSIS WITHOUT CONSULT-II ".

OK or NG
1. OK: INSPECTION END
2. NG:
  1. Perform transfer control unit/output signal inspection. Refer to "TRANSFER CONTROL UNIT INSPECTION TABLE ", "TROUBLE DIAGNOSIS - GENERAL DESCRIPTION".
  2. If NG, recheck transfer control unit pin terminals for damage or loose connection with harness connector.