Bus system monitoring method, device and control unit

The monitoring method has a master subscriber (100) of the bus system used for monitoring the data transmission along the bus system, for initiating a procedure which blocks data transmission upon detection of a data transmission not initiated by the master subscriber, in a given operating condition of the automobile and/or the bus system. Also included are Independent claims for the following: (a) a device for monitoring an automobile bus system; (b) a control unit for monitoring an automobile bus system