Abstract: A data bus system for motor vehicles with a number of electronic bus stations, each having an input port that is connected to the motor vehicle battery to supply power to the bus stations. Each bus station is equipped with a detector circuit and a controllable switch. Each bus station is turned off in the ground state when the ignition is turned off, with the exception of the detector circuit assigned to it, by positioning the controllable switch into an open position in a selective wake state. The controllable switch of each selected bus station is closed by its detector circuit while the temporarily required data exchange between selected bus stations takes place. At least one of the bus stations is defined as the main bus station to control the wake state.