Malfunction Indicator Lamp

Malfunction Indicator Lamp (MIL)

The Malfunction Indicator Lamp (MIL) alerts the driver that the Powertrain Control Module (PCM) has detected an OBD II emission-related component or system fault. When this occurs, an OBD II Diagnostic Trouble Code (DTC) will be set.

- The MIL is located on the instrument panel and is labeled SERVICE ENGINE SOON.
- Power is supplied to the MIL whenever the ignition switch is in the RUN or START position.
- The MIL will remain on in the RUN/START mode as a bulb check or until the CKP signal is detected.
- The light may also be on due to a short to ground of the MIL circuit.
- An engine, with federal calibration, operating in the Failure Mode Effects Management (FMEM) will cause the MIL to be on.
- To turn off the MIL after a repair, a clear code command from the Scan Tool must be sent.
- For any MIL concern, go to Symptom Charts.