Diagnosis Procedure (4WAS Main Control Unit)

POWER SUPPLY AND GROUND CIRCUIT

Diagnosis Procedure (4WAS Main Control Unit)


1. CHECK 4WAS MAIN CONTROL UNIT GROUND

1.Turn the ignition switch OFF.
2.Disconnect 4WAS main control unit harness connector.
3.Check the continuity between 4WAS main control unit harness connector terminal and the ground.





Is the inspection result normal?
YES- GO TO 2.
NO- Repair or replace the harnesses and connectors.

2. CHECK 4WAS MAIN CONTROL UNIT POWER SUPPLY (1)

1.Check the voltage between 4WAS main control unit harness connector terminal and ground.





2.Turn the ignition switch ON.

CAUTION:
Never start the engine.
3.Check the voltage between 4WAS main control unit harness connector terminal and ground.





Is the inspection result normal?
YES- GO TO 4.
NO- GO TO 3.

3. CHECK 4WAS MAIN CONTROL UNIT POWER SUPPLY (2)

1.Turn the ignition switch OFF.
2.Check the 10A fuse (#46).
3.Disconnect IPDM E/R harness connector.
4.Check the continuity between 4WAS main control unit harness connector and IPDM E/R harness connector.





5.Check the continuity between 4WAS main control unit harness connector and ground.





Is the inspection result normal?
YES- Perform the trouble diagnosis for ignition power supply circuit. Ignition Power Supply.
NO- Repair or replace error-detected parts.

4. CHECK 4WAS REAR MOTOR POWER SUPPLY CIRCUIT (1)

1.Remove 4WAS rear motor relay.
2.Check the continuity between 4WAS rear motor relay harness connector and ground.





3.Check the continuity between 4WAS main control unit harness connector and IPDM E/R harness connector.





Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace error-detected parts.

5. CHECK 4WAS REAR MOTOR POWER SUPPLY CIRCUIT (2)

1.Check 20A fusible link (#37).
2.Check the harness for open or short between 4WAS front control unit harness connector No.3 terminal and 20A fusible link (#37).
Is the inspection result normal?
YES- GO TO 6.
NO- Repair or replace error-detected parts.

6. CHECK 4WAS REAR MOTOR POWER SUPPLY CIRCUIT (3)

1.Turn the ignition switch ON.

CAUTION:
Never start the engine.
2.Check the voltage between 4WAS main control unit harness connectors and the ground.





3.Turn the ignition switch OFF.
Is the inspection result normal?
YES- GO TO 7.
NO-Replace 4WAS main control unit. 4WAS Main Control Unit.
- Before replacing 4WAS main control unit, record the self-diagnose results(history). Power Supply And Ground Circuit.

7. CHECK 4WAS REAR MOTOR RELAY

Check 4WAS rear motor relay. Component Inspection.
Is the inspection result normal?
YES- GO TO 8.
NO- Replace 4WAS rear motor relay.

8. CHECK 4WAS REAR MOTOR POWER SUPPLY

1.Connect 4WAS main control unit harness connector.
2.Install 4WAS rear motor relay.
3.Turn the ignition switch ON.

CAUTION:
Never start the engine.
4.Check the voltage between 4WAS main control unit harness connectors and the ground.





Is the inspection result normal?
YES- INSPECTION END.
NO-Replace 4WAS main control unit. 4WAS Main Control Unit.
- Before replacing 4WAS main control unit, record the self-diagnose results(history). Power Supply And Ground Circuit.