Diesel Data: Automotive Repair

S Indicator Circuit Troubleshooting

S Indicator Circuit Troubleshooting
1. Turn the ignition switch ON (II).
2. Shift to the D position.





3. Measure the voltage between TCM connector terminals A18 and A4 or A17 with S mode position selected by turning S mode switch on.
Is there about 10 V?
YES- Go to step 4.
NO- Go to step 5.





4. Measure the voltage between gauge assembly connector terminal B1 and body ground.
Is there 10 V?
YES- Check for blown S indicator bulb. If the indicator bulb is OK, check for loose terminal fit in the TCM and gauge assembly connectors. If necessary, substitute a known-good TCM or gauge assembly and recheck.
NO- Repair open in the wire between TCM connector terminal A18 and the gauge assembly connector B (22P).
5. Turn the ignition switch ON (II).
6. Disconnect TCM connector A (26P).
7. Disconnect gauge assembly connector B (22P).





8. Check for continuity between TCM connector terminal A18 and body ground.
Is there continuity?
YES- Repair short in the wire between TCM connector terminal A18 and the gauge assembly connector B (22P).
NO- Check for loose terminal fit in the TCM and gauge assembly connectors. If necessary, substitute a known-good TCM or gauge assembly and recheck.