Gateway Function
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The BCM acts as a gateway module by receiving information in one format and transmitting it to other modules using another format. For example, the BCM receives the vehicle speed data from the PCM over the High Speed Controller Area Network (HS-CAN), converts the data into a MS-CAN message and sends (gateways) the message to other network modules such as the HVAC and the Audio Front Control Module (ACM). This enables network communication between modules that do not communicate using the same network (HS-CAN or MS-CAN).