CHECK ENGINE Light & Malfunction Indicator Light (MIL)

CHECK ENGINE light and MIL are intended to alert driver of certain malfunctions in EEC-IV system.

Light may also be used to retrieve service codes stored in PCM. When hooked up for KOEO SELF-TEST or KOER SELF-TEST, light will display all codes which turn on light during vehicle operation.

If light comes on during vehicle operation, vehicle should be inspected as soon as possible. Immediately turning off engine is not necessary; vehicle can be driven with light on.

If light comes on and then goes off during vehicle operation, a code will be stored in PCM memory as Continuous Memory Code.

Light should come on when ignition is turned on and go out when engine is started. If light does not come on, see CIRCUIT TEST ML. If hard fault codes are not present, PCM turns out light when it receives a Profile Ignition Pick-Up (PIP) signal.