Test X: Engine Coolant Over Temp Warning Indicator Is Never/Always On (Base Instrument Cluster)

Pinpoint Test X: The Engine Coolant Over Temperature Warning Indicator Is Never/Always On (Base Instrument Cluster)





Normal Operation
The powertrain control module (PCM) receives the engine coolant temperature status through hardwired circuitry to the engine coolant temperature (ECT) sensor (4.0L engine), and from the cylinder head temperature (CHT) sensor (4.6L engine). The instrument cluster receives the engine coolant temperature data from the PCM over the high speed controller area network (HS-CAN). The instrument cluster monitors the engine coolant temperature data received from the PCM and when the engine coolant temperature is high, the engine over temperature warning indicator illuminates.

Possible Causes
- PCM
- instrument cluster