BMW I/K Bus System Overview and Diagnostics
The Body Bus (K-bus) is responsible for the data exchange of telegrams that are required throughout the system. For instance, the ZKE and the IHK are connected to the K-bus.
The K-bus is technically identical to the I-bus. The Body Bus (K-bus) in the E38 is, in the same way as the diagnosis bus (D-bus), the instrumentation bus (I-bus) and the peripheral bus (P-bus), a serial data link between control units.
The functional principle of the K-bus is comparable to that of a telephone conference circuit. All participants are interconnected via the K-bus. Every participant can both receive as well as transmit messages via the K-bus. The K-bus is designed as a single-wire bus system, i.e. the K-bus is a wire system which is used to transmit and receive messages. The high data transfer rate on the K-bus (approx. 10,000 bit/sec) enables distribution of messages between the control units virtually without delay.