Theory Of Operation
WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
The PCM receives odometer readings from the Front Control Module over CAN C. The FCM gets the odometer readings from the Cluster Module over CAN B. U0001-CAN C BUS, and U0141-LOST COMMUNICATION WITH FCM may also set.