Instrument Cluster Description and Operation: Speedometer

The IPC displays the vehicle speed as determined by the ECM. The IPC calculates the kilometers 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 malfunction in the vehicle speed sensor circuit.
• The IPC detects a loss of GMLAN communications from the BCM.