Signal transmission apparatus (50; 100) for a signal transmission between a vehicle component and a bus line, having: a driving component port (52; 102) to which the vehicle component is couplable such that the vehicle component can apply an input signal at a first voltage level to the driving component port (52; 102); a transmission device that is designed to take the applied input signal as a basis for outputting a bus signal at a second voltage level, which does not correspond to the first voltage level; and a bus line port to which the bus line is couplable such that the transmission device can forward output bus signals via the bus line; a control device (58; 110) that is designed to ascertain a bus code on the input signal and a level change on the bus line port, and to take into consideration the bus code ascertained on the input signal and the level change ascertained on the bus line port in order to control output of the bus signal via the transmission device; a reception device that is designed to take into consideration a signal received on the bus line port at the second voltage level in order to output an output signal at the first voltage level to the vehicle component via the driving component port, characterized in that the signal transmission apparatus (50; 100) is in the form of a bidirectional single-wire interface; the reception device is coupled to the driving component port such that the output signal is outputtable to the vehicle component via the driving component port, the driving component port (52; 102) is in the form of a bidirectional single-wire port and the signal transmission apparatus is designed to prevent simultaneous sending and receiving via the driving component port (52; 102) by virtue of the control device (58; 110) being designed to ascertain a prescribed level change on the driving component port (52; 102), and to control the reception device such that output of the output signal via the driving component port (52; 102) is prevented when the prescribed level change is ascertained. a driving component port (52; 102) to which the vehicle component is couplable such that the vehicle component can apply an input signal at a first voltage level to the driving component port (52; 102); a transmission device that is designed to take the applied input signal as a basis for outputting a bus signal at a second voltage level, which does not correspond to the first voltage level; and a bus line port to which the bus line is couplable such that the transmission device can forward output bus signals via the bus line; a control device (58; 110) that is designed to ascertain a bus code on the input signal and a level change on the bus line port, and to take into consideration the bus code ascertained on the input signal and the level change ascertained on the bus line port in order to control output of the bus signal via the transmission device; a reception device that is designed to take into consideration a signal received on the bus line port at the second voltage level in order to output an output signal at the first voltage level to the vehicle component via the driving component port, characterized in that the signal transmission apparatus (50; 100) is in the form of a bidirectional single-wire interface; the reception device is coupled to the driving component port such that the output signal is outputtable to the vehicle component via the driving component port, the driving component port (52; 102) is in the form of a bidirectional single-wire port and the signal transmission apparatus is designed to prevent simultaneous sending and receiving via the driving component port (52; 102) by virtue of the control device (58; 110) being designed to ascertain a prescribed level change on the driving component port (52; 102), and to control the reception device such that output of the output signal via the driving component port (52; 102) is prevented when the prescribed level change is ascertained.