Engine Coolant Temperature Gage
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The ECM sends coolant temperature as determined by the coolant temperature sensor to the BCM via CAN serial data. The IPC displays the engine coolant temperature with the gage when the BCM sends a class 2 message to the IPC indicating coolant temperature percentage. The engine coolant temperature gage defaults to cold (0°) or below if:
- The ECM 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 CAN communications with the ECM.