Vehicle communication system and method for vehicles capable of automatic storing of vehicle identification code

Abstract

A plurality of electronic control units such as engine ECU, navigation ECU and meter ECU as well as a transponder unit is provided in a vehicle so that those control units communicate with each other through a communication line. Each unit stores therein a vehicle identification code which varies from vehicle to vehicle. Each unit checks whether the vehicle identification code is stored in response to a turn-on of power supply. One control unit which does not store the vehicle identification code, it requests a transmission of the vehicle identification code stored in other control units of the vehicle. The other control units responsively transmit the respective stored vehicle identification code to the one control unit. The one control unit, receiving the vehicle identification code writes the transmitted vehicle identification code into its non-volatile memory. Each unit not only controls a vehicle-mounted device, but also diagnoses the vehicle-mounted device. The diagnosis result is transmitted from the transponder unit to an external management station through a radio communication together with the stored vehicle identification code, so that the management station may determine to which a repair instruction should be issued.