Mil Always On: Description
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 Pontiac Grand Prix, 2002 Pontiac Bonneville, 2002 Chevrolet Monte Carlo, 2002 Chevrolet Impala, and 2002 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The battery positive voltage is supplied directly to the Malfunction Indicator Lamp (MIL). The Powertrain Control Module (PCM) turns the MIL ON by grounding the MIL control circuit.