Diagnostic Procedure

With CONSULT-II 

1. Turn ignition switch "ON". (Do not start engine.)
2. Select "DATA MONITOR" mode for "ALL MODE AWD/4WD" with CONSULT-II.
3. Read out ON/OFF switching action of the "2WD SWITCH", "AUTO SWITCH", "LOCK SWITCH" and "4L SWITCH" while operating 4WD shift switch.
   Fig 1: Identifying CONSULT-II Display - DATA MONITOR

   

Without CONSULT-II 

1. Turn ignition switch "ON". (Do not start engine.)
2. Check voltage between transfer control unit harness connector terminals and ground.
   CONNECTOR TERMINAL VOLTAGE REFERENCE
   
   

   Connector	Terminal	Condition	Voltage (Approx.)
   M152	9 - ground	4WD shift switch: 2WD	Battery voltage
   		4WD shift switch: AUTO, 4H or 4LO	0V
   	18 - ground	4WD shift switch: 4H	Battery voltage
   		4WD shift switch: 2WD, AUTO or 4LO	0V
   	23 - ground	4WD shift switch: 4LO	Battery voltage
   		4WD shift switch: 2WD, AUTO or 4H	0V
   	24 - ground	4WD shift switch: AUTO	Battery voltage
   		4WD shift switch: 2WD, 4H or 4LO	0V

   Fig 2: Checking Voltage Between Transfer Control Unit Harness 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 Harness 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 Harness Connector Terminal 1 And Ground

OK or NG 

OK: GO TO 3.

NG: Check the following. If any items are damaged, repair or replace damaged parts.

• Harness for short or open between transfer shut off relay harness connector E155 terminal 5.
• Power supply circuit for transfer control unit. 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 9 and 4WD shift switch harness connector M141 terminal 2.
   • Transfer control unit harness connector M152 terminal 18 and 4WD shift switch harness connector M141 terminal 5.
   • Transfer control unit harness connector M152 terminal 23 and 4WD shift switch harness connector M141 terminal 6.
   • Transfer control unit harness connector M152 terminal 24 and 4WD shift switch harness connector M141 terminal 3.

     Continuity should exist. 

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

OK or NG 

OK: GO TO 4.

NG: Repair or replace damaged parts.

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

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

   Connector	Terminal	Condition	Continuity
   M141	1 - 2	4WD shift switch: 2WD	Yes
   		4WD shift switch: AUTO, 4H and 4LO	No
   	1 - 3	4WD shift switch: AUTO	Yes
   		4WD shift switch: 2WD, 4H and 4LO	No
   	1 - 4	4WD shift switch: 2WD	No
   		4WD shift switch: AUTO, 4H and 4LO	Yes
   	1 - 5	4WD shift switch: 4H	Yes
   		4WD shift switch: 2WD, AUTO, and 4LO	No
   	1 - 6	4WD shift switch: 4LO	Yes
   		4WD shift switch: 2WD, AUTO 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 "REMOVAL AND INSTALLATION ".