MIL is an abbreviation for the Malfunction Indicator Lamp (MIL).
If the Engine Control Module (ECM) recognizes a malfunction that leads to increased emissions values, it indicates them by lighting the Malfunction Indicator Lamp (MIL) which is located in the instrument cluster.
The Engine Control Module (ECM) switches on the Malfunction Indicator Lamp (MIL) after the ignition is switched on. Shortly after the engine is started, The Malfunction Indicator Lamp (MIL) goes out if the Engine Control Module (ECM) does not detect a malfunction that increases the emissions values.
If the Engine Control Module (ECM) recognizes a malfunction that leads to increased emissions during the operation of the engine, the Engine Control Module (ECM) switches on the Malfunction Indicator Lamp (MIL) and an entry is stored in the DTC memory of the Engine Control Module (ECM).