Instrument Cluster Description & Operation: Speedometer

The instrument panel cluster (IPC) displays the vehicle speed based on serial data message from the body control module (BCM). The BCM receives vehicle speed data from the engine control module (ECM) via the serial data circuit. The speedometer will default to 0 km/h (0 mph) if:

• The ECM detects a malfunction in the vehicle speed sensor circuit.
• The BCM detects a loss of serial data communications with the ECM.
• The IPC detects a loss of serial data communications with the BCM.