Patent ID: 7409275

Claim:
A vehicle diagnostic system comprising: an electronic control unit for controlling and monitoring vehicle equipment; a radio communication means for communicating between the electronic control unit on said vehicle and a telecommunication equipment, and for transmitting a communication diagnostic signal to said electronic control unit, and for receiving a response signal according to said communication diagnostic signal from the electronic control unit, the telecommunication equipment being outside the vehicle and receiving a communication from the radio communication means; a communication line for connecting said electronic control unit and said radio communication means, wherein at least the communication diagnostic signal is communicated to said electronic control unit through said communication line, and wherein said radio communication means transmits said communication diagnostic signal to said electronic control unit as necessary and in response, said electronic control unit sends back the response signal to said radio communication means; and said radio communication means utilizes the response signal to determine whether or not the communicating through said communication line is being performed normally.