MOST bus: Notes
WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
The MOST (Media Oriented Systems Transport) network uses a ring structure to enable data communication between the various control units.
Data transfer is by means of fibre-optic cable.
Data transfer on the ring bus takes place in one direction only.
On the MOST ring, messages can only be transmitted provided the bus ring is complete and fully functional. If, for example, the voltage supply or the diode of a control unit is defective, it is no longer possible to communicate with the control units on the MOST bus. An exception is the gateway control unit of the headunit (Rad2, CHAMP, M-ASK, CCC or following). The control unit is connected both to the MOST data bus and the K-CAN.