MIL Operation

MIL is located on the instrument panel and is displayed as CHECK ENGINE light on Alero and Grand Am and on Impala and Monte Carlo, the MIL is displayed as an engine icon with ENGINE under the icon.

MIL Function

• The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible.
• The MIL illuminates during a bulb test and a system test.
• A DTC will be stored if a MIL is requested by the diagnostic.

MIL Illumination

• The MIL will illuminate with ignition switch in RUN position and the engine not running.
• The MIL will turn OFF when the engine is started.
• The MIL will remain ON if the self-diagnostic system has detected a malfunction.
• The MIL may turn OFF if the malfunction is not present.
• If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated so long as the ignition switch is in RUN position.
• If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.