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 GAUGE fuse provides the circuit with 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 turned ON. If the MIL is always ON or OFF, use the hand-held tester and follow the procedures below to determine the cause of the problem.
If the ECM detects trouble, the MIL illuminates. At this time, the ECM records a DTC in the memory.

Wiring Diagram:

Step 4-5:

Step 6-7:

INSPECTION PROCEDURE

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