If a vehicle is equipped with a modern CAN data bus (Controller Area Network), the information exchange within the on-board vehicle network is carried out on a digital basis and not, as is usual, on an analogue basis. To process these digital data and transfer the information required for the trailer operation the electrical kit must have a corresponding CAN data bus trailer module, so that all functions (reverse lighting, indicators etc.) required for the trailer can be controlled.A vehicle equipped with a CAN data bus must almost always be activated for towing. Universal electrical kits can, as a rule, not be used in vehicles equipped with a CAN data bus.