| CAN Bus The amount of electronic componentry in motor vehicles is constantly on the increase. As conventional wiring techniques with lengthy routing are no longer able to handle the quantity of data that needs to be exchanged, CAN data buses are used instead. The term Controller Area Network (CAN) refers to a serial bus system that was specially developed for use in motor vehicles. The CAN data bus serves as the basis for digital data exchange between sensors, actuators and control units, ensuring that several control units are able to process the information from one sensor and control their actuators accordingly. Quite apart from the short wiring routes, the CAN data bus has the particular advantage that, if one component fails, the rest of the system continues to work normally, greatly reducing the risk of a complete system failure. Even the older electrical systems in the vehicle are increasingly being controlled via the CAN data bus for added safety and convenience. The wireless light switch in the Golf is an example of just such a system. The driver merely has to select the lighting mode with the switch and the control unit will supply the lights with the required power. This allows convenience features such as the "coming home" function to be added. Due to the variation in the signal repetition rates and the volume of data produced, CAN bus systems are subdivided into three categories: the drive train CAN bus transmits the signals from control units such as the engine management unit, the transmission control and the ABS/ESP unit. The comfort CAN bus is crucial for the climate control functions, for instance, just as the infotainment CAN bus is for the signals received from car radios with speed-sensitive volume control. |
