MIL Circuit Troubleshooting

Engine

MIL Circuit Troubleshooting

MIL Circuit Troubleshooting

1. Gauge control module (tach) check:

Gauge control module (tach) check
-1. Turn the ignition switch to ON (II).

-2. Do the gauge self-diagnostic function Testing and Inspection.

Does the MIL flash?
-YES- Go to step 2.
-NO- Substitute a known-good gauge control module (tach) Gauge Control Module (Tach) Removal and Installation, then recheck. If the symptom/indication goes away with a known-good gauge control module, replace the original gauge control module (tach) Gauge Control Module (Tach) Removal and Installation.

2. ECM check:

ECM check
-1. Connect the HDS to the DLC.

-2. Check the SCS in the DATA LIST with the HDS.

Is a short indicated?
-YES- Go to step 3.
-NO- Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, 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.

3. Shorted wire check (SCS line):

Shorted wire check (SCS line)
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Disconnect the HDS.

-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the SCS wire between the ECM (A42) and the DLC.
-NO- The SCS wire is OK. Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, 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.