Engine Coolant Temperature Gauge

The instrument cluster displays the engine coolant temperature as determined by the engine control module (ECM). The ECM sends the engine coolant temperature information via a High Speed CAN-Bus signal to the body control module (BCM). The BCM then sends the information via a Low Speed CAN-Bus signal to the instrument cluster to display the engine coolant temperature. The engine coolant temperature gauge defaults to 40°C (104° F) or below if:

• The ECM detects a malfunction in the engine coolant temperature sensor circuit.
• The BCM detects a loss of serial data communications with the ECM.
• The instrument cluster detects a loss of serial data communications with the BCM.