Malfunction Indicator Lamp Inoperative: Description
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
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. There should be a steady Malfunction Indicator Lamp (MIL) with the ignition on and the engine off.