Gateway Modules
WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
The Instrument Panel Cluster (IPC) and Body Control Module (BCM) are gateway modules. The IPC translates messages on the HS-CAN to the I-CAN and vice versa. The BCM translates messages on the HS-CAN to the MS-CAN and vice versa. This allows a message to be distributed throughout all three networks.
The IPC and the BCM are the only modules on this vehicle that have this ability.