Instrument Cluster Description and Operation: Speedometer
The IPC displays the vehicle speed as determined by the ECM. The IPC calculates the kilometres based on the GMLAN vehicle speed information from the BCM. The speedometer defaults to 0 km/h if the IPC detects a loss of GMLAN communications with both the ECM.
- The ECM detects a mulfunction in the vehicle speed sensor.
- The IPC detects a loss of GMLAN communications from the BCM or ECM.