Engine Coolant Temperature Gage
WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
The IPC displays the engine coolant temperature as determined by the PCM. The body control module (BCM) receives a class 2 message from the PCM indicating the engine coolant temperature. The BCM converts the engine coolant temperature into a percent gage deflection. The IPC receives a message from the BCM via the serial peripheral interface (SPI) indicating the requested gage position. The engine coolant temperature gage defaults to 38°C (100°F) or below if:
- The PCM detects a malfunction in the engine coolant temperature sensor circuit.
- The BCM detects a loss of class 2 communications with the PCM.
- The IPC detects a loss of SPI communications with the BCM.