its called CAN bus.... its accessible through the OBDII port on newer vehicles
My 406 has a 3 wire vehicle wide bus which allows every component to communicate with everything else, if i could crack the protocol I could write to any LCD , A/C, wing mirrors, lights, alarm, radio - EVERYTHING. anyone had an experience with the pug system ? or any other similar VAN's?
www.digital-car.co.uk - The UK CarPC Forum