Malfunction Indicator Light (MIL)

MIL may also be referred to as Service Engine Soon light. If all systems are normal, immediately after ignition switch is turned on, MIL will illuminate for 5 seconds. Go out. When PCM determines an emissions related malfunction exists, PCM will turn the MIL on. If 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 Diagnostic Trouble Codes (DTCs) present, diagnose MIL circuit malfunction. See MALFUNCTION INDICATOR LIGHT (MIL)  under DIAGNOSTIC CIRCUIT CHECK.