In the Daimler-Benz "Actros", a data bus is used instead of the harnesses used up to now. Signals are sent via 3 lines for each consumer and the corresponding consumers actuated via a decoder and encoder (transmitter and receiver). In our model, the consumers of a door are actuated (mirror adjustment in 2 directions, mirror heating, central locking, window winders and one light). The actuation of the consumers can be measured via measurement bushes. The data signals can be portrayed with any customary oscilloscope. The Multiplex data bus replaces an entire cable tree with one data line.