Operation CHARM: Car repair manuals for everyone.

Malfunction Indicator Lamp: Testing and Inspection

MIL CIRCUIT

CIRCUIT DESCRIPTION
The Malfunction Indicator Lamp (MIL) is used to indicate the ECM's detection of a vehicle malfunction. The instrument panel IG2 fuse provides circuit power and the ECM provides the circuit ground that illuminates the MIL.

MIL operations should be checked visually:

The MIL should be illuminated when the ignition is first turned ON. If the MIL is always ON or OFF, use the hand-held tester or OBD II scan tool and follow the procedures to determine the cause of problem.

Wiring Diagram:






INSPECTION PROCEDURE




Step 1 - 3:




Step 4:






HINT: Troubleshoot each trouble symptom in accordance with the chart.