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

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

Normal Operation
The MIL is controlled by the instrument cluster (IC) using data sent from the PCM over the high speed controller area network (HS-CAN) communication bus. If the MIL status message is missing or invalid for less than 5 seconds, the MIL remains in the last indication mode (on or off), based upon the last known good data message. If the MIL status message is missing for more than 5 seconds, the instrument cluster (IC) sets DTC U0101 in continuous memory and defaults the MIL on. If the MIL message is deemed invalid for longer than 5 seconds, the instrument cluster (IC) sets DTC U2023 and defaults the MIL on.

NOTE: If DTC U0101 is set in the instrument cluster (IC), other observable symptoms may be an inoperative speedometer, tachometer or odometer.

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

R1-R4:

R5: