Instrument Cluster Description and Operation: Odometer

The vehicle odometer is calculated and stored electronically in the body control module (BCM) and is sent via GMLAN to the instrument panel cluster (IPC) for display. The BCM calculates and stores the mileage based on the vehicle speed GMLAN message from the engine control module (ECM). The IPC displays the season odometer information from the BCM in the driver information center (DIC). If the stored VIN in the IPC matches the GMLAN VIN, the odometer data from the BCM will then be displayed. If the VINs do not match, the IPC will freeze the odometer value for the entire ignition cycle.