FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

MIL Circuit Troubleshooting




MIL Circuit Troubleshooting

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

2. Do the gauge self-diagnostic function Initial Inspection and Diagnostic Overview.

Does the MIL flash?

YES -

Go to step 3.

NO -

Substitute a known-good gauge control module (tach), and recheck. If the MIL circuit is OK, replace the original gauge control module (tach) Gauge Control Module Replacement.�

3. Connect the HDS to the DLC.

4. Check the SCS in the DATA LIST with the HDS.

Is a short indicated?

YES -

Go to step 5.

NO -

Update the ECM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM, then recheck. If the symptom/indication goes away and the ECM was updated, troubleshooting is complete. If the symptom/indication goes away and the ECM was substituted, replace the original ECM Service and Repair.�

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

6. Disconnect ECM connector A (44P), then disconnect the HDS.

7. Check for continuity between ECM connector terminal A31 and body ground.





Is there continuity?

YES -

Repair short in the wire between the ECM (A31) and the SRS unit, the EPS control unit, or the DLC.�

NO -

Update the ECM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM, then recheck. If the symptom/indication goes away and the ECM was updated, troubleshooting is complete. If the symptom/indication goes away and the ECM was substituted, replace the original ECM Service and Repair.�