Engine Coolant Temperature Gage
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) sends coolant temperature as determined by the coolant temperature sensor to the body control module (BCM) via the controller area network (CAN) serial data. The instrument panel cluster (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 (ECT) gage defaults to cold (0°) or below if:
- The ECM detects a malfunction in the ECT 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.