Pinpoint Test 18: The Malfunction Indicator Lamp (MIL) Is Never/Always On

PINPOINT TEST 18: THE MALFUNCTION INDICATOR LAMP (MIL) IS NEVER/ALWAYS ON

Normal Operation

The MIL is controlled by the instrument cluster using data sent from the PCM over the high speed controller area network (HS-CAN) communication bus. If the MIL status message is missing for less than 5 seconds, the MIL remains in the last indication mode (on or off). If the MIL status message is missing for more than 5 seconds, the instrument cluster sets DTC U0100 in continuous memory and defaults the MIL on.
NOTE:If DTC U0100 is set in the instrument cluster, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

Possible Causes
- PCM
- Instrument cluster

Diagnostic Procedure