Test Y: The Low Oil Pressure Reconfigurable Telltale Indicator Is Never/Always On

PINPOINT TEST Y: THE LOW OIL PRESSURE RECONFIGURABLE TELLTALE INDICATOR IS NEVER/ALWAYS ON

Y1-Y2:

Y3-Y6:

Y6-Y8:

Y8-Y10:

Normal Operation
The instrument cluster uses engine rpm data, sent from the powertrain control module (PCM) over the high speed controller area network (HS-CAN) communication bus, to determine whether the engine is running. The normally open engine oil pressure switch is hardwired to the instrument cluster through circuit CMC24 (GY). The instrument cluster provides a reference voltage to the engine oil pressure switch when the ignition key is in the RUN position. When there is low or no oil pressure, the engine oil pressure switch remains open, the instrument cluster detects no change in the reference voltage, and the low oil pressure reconfigurable telltale is turned on. When the engine is running with sufficient oil pressure, the PCM sends an rpm status message to the cluster and the engine oil pressure switch closes, providing a ground, which pulls the reference voltage from the instrument cluster low, turning on the low oil pressure reconfigurable telltale. If the engine rpm status message is missing or if the data is deemed invalid by the instrument cluster for greater than 5 seconds, the instrument cluster sets DTC U0100 and defaults the low oil pressure reconfigurable telltale on.

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

Possible Causes
- Circuit CMC24 (GY) open, short to ground or voltage
- Engine oil pressure switch
- Base engine concern
- Instrument cluster