Gateway Module
WARNING: This page is about a different car, the 2014 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
The IPC and BCM are gateway modules. The IPC translates messages on the Medium Speed Controller Area Network (MS-CAN) to the Infotainment Controller Area Network (I-CAN) and vice versa. The BCM translates messages on the High Speed Controller Area Network (HS-CAN) to the Medium Speed Controller Area Network (MS-CAN) and vice versa. This allows a message to be distributed throughout all 3 networks.
The IPC and the BCM are the only modules on this vehicle that have this ability.