Engine Coolant Temperature Gage
WARNING: This page is about a different car, the 2003 Pontiac Sunfire and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The PCM sends coolant temperature as determined by the coolant temperature sensor to the BCM via class 2. The IPC displays the engine coolant temperature as determined by the BCM. The IPC receives a class 2 message from the BCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 75°C (160°F) or below if:
- The PCM detects a malfunction in the engine coolant temperature sensor circuit.
- The IPC detects a loss of class 2 communications with the BCM.
- The BCM detects a loss of class 2 communications with the PCM.