Circuit Description

The MIL is used to indicate the ECM's detection of a vehicle malfunction.

The instrument panel GAUGE fuse provides the 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 switch is first turned to on. If the MIL is always ON or OFF, use the hand-held tester or OBD II scan tool and follow the procedures below to determine the cause of the problem.