Engine Coolant Temperature

The BCM handles the control of engine temperature gauge display and the high temperature indicator. The PCM reads the engine coolant temperature sensor, filters the data, and sends the engine coolant temperature to the instrument cluster via a Class 2 serial data message. The PCM transmits the Class 2 serial data coolant temperature report messages to the instrument cluster in order to determine the temperature gauge display and to the high temperature indicator control.

The instrument cluster receives the engine temperature data in the Class 2 serial data message from the PCM and converts this message into a temperature gauge pointer position which drives the gauge pointer. The instrument cluster also uses this message in order to determine the high temperature indicator control.

The BCM looks for the high temperature indicator Class 2 serial data report from the instrument cluster and triggers a chime when the indicator is on.