Instrument Cluster Description and Operation: Speedometer

The IPC displays the vehicle speed based on the information from the BCM. The PCM calculates the vehicle speed based on the CAN serial data message indicating the wheel reference speed from the electronic brake control module (EBCM). The PCM sends a CAN serial data message to the BCM indicating the vehicle speed. The BCM sends a class 2 message to the IPC indicating the vehicle speed.

The speedometer defaults to 0 km/h (0 mph) when any of the following occur:

• The EBCM detects a malfunction in the vehicle speed sensor circuit.
• The PCM detects a loss of CAN communications with the EBCM.
• The BCM detects a loss of CAN communications with the PCM.
• The IPC detects a loss of class 2 communications with the BCM.