Malfunction Indicator Light (Mil): Notes

Vehicles are equipped with a Malfunction Indicator Light (MIL). As a bulb check, light will illuminate for about 5 seconds when ignition is turned on. The MIL will also illuminate when a system failure is detected, and a corresponding Diagnostic Trouble Code (DTC) will set in ECM memory.

The Electronic Control Module (ECM) is equipped with a self-diagnostic system, which detects system failures or abnormalities. When a malfunction occurs, the ECM will illuminate the MIL on the instrument panel and a corresponding DTC will be stored in ECM. To retrieve stored DTC(s), see RETRIEVING CODES  . Malfunctions are recorded as hard failures or as intermittent failures.