Fuel Level Sensing

The Powertrain Control Module (PCM) reads the fuel level sensor, filters the data, and then sends a fuel level Class 2 serial data message to the instrument cluster for display. The instrument cluster drives the fuel gauge pointer. The PCM is responsible for sending a fuel related Class 2 serial data message so that fuel level sensing is started when Ignition 0 is ON, however the fuel level is not displayed until Ignition 1 is ON. This is done in order to reduce the latency of the fuel gauge display during key-on. The Body Control Module (BCM) looks for the low fuel indicator Class 2 serial data report from the instrument cluster and triggers a chime when the indicator is ON.