The VTM-4 Indicator Does Not Come on
The VTM-4 indicator does not come on1. Do the gauge control module self-diagnosis function.
Is the gauge control module OK?
YES - Go to step 2.
NO - Go to the gauge control module input test 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 the No. 14 terminal of the VTM-4 control unit connector A (22P) and No. 11 terminal of the VTM-4 control unit connector B (12P) to body ground with jumper wires.
4. Turn the ignition switch ON (II).
5. Watch 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, replace the VTM-4 control unit.
NO - Go to step 6.
6. Turn the ignition switch OFF.
7. Disconnect gauge control module connector A (30P).
8. Connect the No. 3 terminal of the gauge control module connector C (20P) to body ground with a jumper wire.
9. Check for continuity between the No. 14 terminal of the VTM-4 control unit connector A (22P) and body ground, and the No. 11 terminal of the VTM-4 control unit connector B (12P) and body ground.
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.
NO - Repair open in the wire between the gauge control module (C3) and the VTM-4 control unit.