Engine Coolant Temperature Gage

The engine control module (ECM) sends the coolant temperature to the instrument panel module (IPM) via GMLAN. The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the IPM. The IPC receives a GMLAN message from the IPM indicating the engine coolant temperature. The engine coolant temperature gage, if equipped, defaults to a minimum when:

• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The IPC detects a loss of GMLAN communications with the IPM.
• The IPM detects a loss of GMLAN communications with the ECM.

Refer to Cooling System Description and Operation for more information.