Circuit Description: Notes

Battery positive voltage is supplied to the malfunction indicator lamp (MIL) through a logic module in the instrument panel cluster (IPC). The powertrain control module (PCM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.

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 PCM.

MIL Illumination

• The MIL will illuminate with ignition switch ON 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 ON.
• If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.