Malfunction Indicator Light

MIL may also be referred to as SERVICE ENGINE SOON light. If all systems are normal, immediately after ignition switch is turned to ON position, MIL will illuminate for 5 seconds, then go out. When ECM/PCM determines an emission system related malfunction exists, ECM/PCM will turn the MIL on. If ECM/PCM determines that the malfunction no longer exists, it will turn the MIL off.

If MIL will not come on for bulb check or MIL stays on with no DTCs present, diagnose MIL circuit malfunction. See MALFUNCTION INDICATOR LIGHT DIAGNOSIS  .