Test N: The Malfunction Indicator Lamp (MIL) Is Never/Always On

PINPOINT TEST N: THE MALFUNCTION INDICATOR LAMP (MIL) IS NEVER/ALWAYS ON

Normal Operation
The malfunction indicator lamp (MIL) is illuminated when a mis-fire condition exists or an emission-related concern is detected by the PCM. The instrument cluster (IC) receives the MIL data from the PCM over the high speed controller area network (HS-CAN) communication bus. If an emissions concern exists, the PCM sets a DTC and sends a message to the instrument cluster (IC) to illuminate the MIL. If a mis-fire condition exists, the PCM sets a DTC and sends the instrument cluster (IC) a message to flash the MIL. If the MIL message is missing or if the data is deemed invalid by the instrument cluster (IC) for greater than 5 seconds, the instrument cluster (IC) sets DTC U0100 and defaults the MIL on.

NOTE: If U0100 is set in the instrument cluster (IC) other symptoms may also be present such as an inoperative speedometer, tachometer or temperature gauge.

This pinpoint test is intended to diagnose the following:
- PCM
- Instrument cluster (IC)

N1-N5: