Test V: The Engine Over-Temperature Warning Indicator Is Never/Always On
PINPOINT TEST V: THE ENGINE OVER-TEMPERATURE WARNING INDICATOR IS NEVER/ALWAYS ONV1-V4:
Normal Operation
The engine temperature status is transmitted to the powertrain control module (PCM) from the cylinder head temperature sensor through circuit 8-RJ33 (WH/VT). The PCM transmits an over-temperature status to the instrument cluster over the communication network. When the engine temperature, as measured at the cylinder head, reaches 121°C (250°F), the PCM enters the first stage of the fail-safe mode and sends a command message to the instrument cluster to turn on the engine over-temperature warning indicator. The instrument cluster logs diagnostic trouble code (DTC) U1073 if the instrument cluster fails to receive the engine temperature status from the PCM.
Possible Causes
- PCM
- instrument cluster