The VTM-4 Lock Indicator Does Not Come On For About 4 Seconds When The Ignition Switch Is Turned On (II)

Rear Differential Symptom Troubleshooting - The VTM-4 LOCK indicator does not come on for about 4 seconds when the ignition switch is turned ON (II)

The VTM-4 LOCK indicator does not come on for about 4 seconds when the ignition switch is turned ON (II)

NOTE: Before you troubleshoot, review the general troubleshooting information Initial Inspection and Diagnostic Overview.

1. Disconnect VTM-4 control unit connector A (22P).

2. Connect VTM-4 control unit connector terminal A16 to body ground with a jumper wire.






3. Turn the ignition switch to ON (II).

4. Check the VTM-4 LOCK indicator.

Does the VTM-4 LOCK indicator come on?

YES -

Check for poor connections or loose terminals at the VTM-4 control unit connectors. If the connections are OK, substitute a known-good VTM-4 control unit Service and Repair and recheck. If the symptom/indication goes away with the known-good VTM-4 control unit, replace the original VTM-4 control unit Service and Repair.�

NO -

Go to step 5.

5. Turn the ignition switch to LOCK (0).

6. Remove the jumper wire from VTM-4 control unit connector terminal A16.

7. Remove the VTM-4 LOCK switch.

8. Connect the VTM-4 LOCK switch 5P connector terminal No. 5 to body ground with a jumper wire.






9. Check for continuity between VTM-4 control unit connector terminal A16 and body ground.





Is there continuity?

YES -

Go to step 10.

NO -

Repair an open in the wire between VTM-4 control unit (A16) and the VTM-4 LOCK switch.�

10. Remove the jumper wire from the VTM-4 LOCK switch.

11. Turn the ignition switch ON (II).

12. Measure the voltage between the VTM-4 LOCK switch 5P connector terminal No. 2 and body ground.





Is there battery voltage?

YES -

Replace the VTM-4 LOCK indicator bulb Service and Repair.�

NO -

Repair an open in the wire between the No. 2 terminal of the VTM-4 LOCK switch 5P connector and the under-dash fuse/relay box.�