Circuit Description

The 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.