Speedometer Head: Description and Operation

SPEEDOMETER

The IPC displays the vehicle speed based on the information from the BCM. The BCM receives a class 2 message from the PCM indicating the vehicle speed. The PCM calculates the vehicle speed based on the class 2 message indicating the wheel reference speed from the EBCM if:
- The PCM detects a malfunction in the vehicle speed sensor circuit.
- The IPC detects a loss of class 2 communications with the BCM.

The speedometer defaults to 0 km/h (0 mph) if the BCM detects a loss of class 2 communications with both the PCM and the EBCM.