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, and recheck. If the MIL circuit is OK, replace the original gauge control module (tach) Gauge Control Module (Tach) Removal And Installation.

2. PCM check:

PCM 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 PCM PCM Update if it does not have the latest software, or substitute a known-good PCM Service and Repair, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM 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 PCM (A42), the back-up control unit, the power control unit, the keyless access control unit, the head light leveling control unit, and the DLC.
-NO- The SCS wire is OK. Update the PCM PCM Update if it does not have the latest software, or substitute a known-good PCM Service and Repair, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair.