Advanced automotive multiplexed wiring system

The paper describes a wiring system which incorporates 4-bit microcontrollers to reduce costs. These devices may be custom produced with the specialised control program held on chip. Using these, a centralised control system with up to eight remote switching and monitoring units may be configured with a single data communications channel and power supply common to each. Standard automotive cable is used for this purpose as no screening is required with most vehicles. The system controls up to 64 automotive devices and, in the case of lights, can detect a broken bulb while either on or off. A special feature of the system is the provision of electronic overload protection on each output stage of the remote units. It is believed that this is the first time that such protection has been incorporated into an automotive wiring system and has been made possible by the use of a custom integrated circuit.