Malfunction Indicator Lamp (MIL)
WARNING: This page is about a different car, the 2002 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
After the engine is started, the MIL will prove out for a duration of three seconds. If the instrument cluster does not receive a message from the PCM within five seconds, it will send two messages to the PCM and attempt to reestablish communication. If the instrument cluster is unable to reestablish communication, the instrument cluster will illuminate the MIL and log a diagnostic trouble code (DTC).