Diesel Data: Automotive Repair

The VTM-4 Indicator Does Not Come On




Rear Differential Symptom Troubleshooting - The VTM-4 indicator does not come on

The VTM-4 indicator does not come on

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

1. Do the gauge control module self-diagnosis function Initial Inspection and Diagnostic Overview.

Is the gauge control module OK?

YES -

Go to step 2.

NO -

Go to the gauge control module input test Initial Inspection and Diagnostic Overview and check for an open or short in the power and ground.�

2. Disconnect the VTM-4 control unit connectors A (22P) and B (12P).

3. Connect VTM-4 control unit connector terminal A14 and VTM-4 control unit connector terminal B11 to body ground with jumper wires respectively.





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

5. Check the VTM-4 indicator.

Does the VTM-4 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 6.

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

7. Remove the jumper wire from VTM-4 control unit connector terminal A14 and VTM-4 control unit connector terminal B11

8. Disconnect gauge control module connector C (20P).

9. Connect gauge control module connector terminal C3 to body ground with a jumper wire.






10. Check for continuity between VTM-4 control unit connector terminal A14, and VTM-4 control unit connector terminal B11 to body ground respectively.





Is there continuity?

YES -

Substitute a known-good gauge control module and recheck. If the symptom/indication goes away with the known-good gauge control module, replace the original gauge control module Service and Repair.�

NO -

Repair an open in the wire between gauge control module (C3) and the VTM-4 control unit (A14 or B11). �