Diagnosis Procedure (4WAS Front Control Unit)

POWER SUPPLY AND GROUND CIRCUIT

Diagnosis Procedure (4WAS Front Control Unit)


1. CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY (1)

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





4.Turn the ignition switch ON.

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





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 2.

2. CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY (2)

1.Turn the ignition switch OFF.
2.Check the 40A fusible link (Q).
3.Check the harness for open or short between 4WAS front control unit harness connector No.11 terminal and 40A fusible link (Q).
Is the inspection result normal?
YES- Perform the trouble diagnosis for power supply circuit. Battery Power Supply.
NO- Repair or replace error-detected parts.

3. CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY (3)

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





4.Turn the ignition switch ON.

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





Is the inspection result normal?
YES- GO TO 5.
NO- GO TO 4.

4. CHECK 4WAS FRONT CONTROL UNIT POWER SUPPLY (4)

1.Turn the ignition switch OFF.
2.Check the 10A fuse (#3).
3.Disconnect fuse block (J/B) harness connector.
4.Check the continuity between 4WAS front control unit harness connector and fuse block (J/B).





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

5. CHECK 4WAS FRONT CONTROL UNIT GROUND

Check the continuity between 4WAS front control unit harness connector terminal and the ground.





Is the inspection result normal?
YES- INSPECTION END
NO- Repair or replace the harnesses and connectors.