Diagnostic Procedure

With CONSULT-II 

1. Turn ignition switch "ON".
2. Select "DATA MONITOR" mode for "ALL MODE AWD/4WD" with CONSULT-II.
3. Read out ON/OFF switching action of the "2WD SWITCH", "4H SWITCH", "4L SWITCH" with operating 4WD shift switch.
   Fig 1: Identifying CONSULT II - DATA MONITOR Screen

   

Without CONSULT-II 

1. Turn ignition switch "ON".
2. Check voltage between transfer control unit harness connector terminals and ground.
   CONNECTOR TERMINAL VOLTAGE REFERENCE
   
   

   Connector	Terminal	Condition	Voltage (Approx.)
   M152	14 - Ground	4WD shift switch: 2WD	Battery voltage
   		4WD shift switch: 4H and 4LO	0V
   	15 - Ground	4WD shift switch: 4H	Battery voltage
   		4WD shift switch: 2WD and 4LO	0V
   	16 - Ground	4WD shift switch: 4LO	Battery voltage
   		4WD shift switch: 2WD and 4H	0V

Fig 2: Checking Voltage Between Transfer Control Unit Connector Terminals And Ground

OK or NG 

OK: GO TO  5.

NG: GO TO 2.

1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect 4WD shift switch harness connector.
3. Check voltage between 4WD shift switch harness connector terminal 1 and ground.
   CONNECTOR TERMINAL VOLTAGE REFERENCE
   
   

   Connector	Terminal	Voltage (Approx.)
   M141	1 - Ground	0V

   Fig 3: Checking Voltage Between 4WD Shift Switch Connector Terminal 1 And Ground

   
4. Turn ignition switch "ON". (Do not start engine.)
5. Check voltage between 4WD shift switch harness connector terminal 1 and ground.
   CONNECTOR TERMINAL VOLTAGE REFERENCE
   
   

   Connector	Terminal	Voltage (Approx.)
   M141	1 - Ground	Battery voltage

   Fig 4: Checking Voltage Between 4WD Shift Switch Connector Terminal 1 And Ground

   

OK or NG 

OK: GO TO 3.

NG:

1. Check harness for short or open between 4WD shift switch harness connector terminal 1 and transfer shut off relay 2 harness connector E157 terminal 5 and 10A fuse (No. 61 located in the fuse block). If any items are damaged, repair or replace damaged parts.
2. Perform trouble diagnosis for power supply circuit. Refer to "POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT ".

1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the 4WD shift switch harness connector.
3. Check continuity between the following terminals.
   • Transfer control unit harness connector M152 terminal 14 and 4WD shift switch harness connector M141 terminal 3.
   • Transfer control unit harness connector M152 terminal 15 and 4WD shift switch harness connector M141 terminal 5.
   • Transfer control unit harness connector M152 terminal 16 and 4WD shift switch harness connector M141 terminal 6.

     Continuity should exist. 

     Fig 5: Checking Continuity Between 4WD Shift Switch And Transfer Control Unit Connector Terminals

     

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

OK or NG 

OK: GO TO 4.

NG: Repair or replace damaged parts.

1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Remove 4WD shift switch harness connector.
3. Operate 4WD shift switch and check continuity between 4WD shift switch terminals.
   CONNECTOR TERMINAL CONTINUITY REFERENCE
   
   

   Terminal	Condition	Continuity
   1 - 3	4WD shift switch: 2WD	Yes
   	4WD shift switch: 4H and 4LO	No
   1 - 5	4WD shift switch: 4H	Yes
   	4WD shift switch: 2WD and 4LO	No
   1 - 6	4WD shift switch: 4LO	Yes
   	4WD shift switch: 2WD and 4H	No

   Fig 6: Checking Continuity Between 4WD Shift Switch Terminals

   

OK or NG 

OK: GO TO 5.

NG: Replace 4WD shift switch.

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.

Perform the self-diagnosis, after driving a vehicle for a while.

OK or NG 

OK: Inspection End.

NG: Replace transfer control unit. Refer to "TRANSFER CONTROL UNIT ".