Driver Information Center (DIC) Description and Operation: Odometer
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
The odometer information is stored in the body control module (BCM) and is transmitted to the instrument panel cluster (IPC) for display in the driver information center (DIC). The IPC stores a backup copy of the odometer value in case the IPC does not receive a valid odometer reading form the BCM. The last known good odometer value from the BCM is displayed by the IPC before ERROR is displayed in the DIC.