Abstract: A vehicle user can request emergency or roadside assistance from a response center by activating a button in the vehicle. The global positioning system is used to continuously store the vehicle location. A cellular telephone network is used to contact a response center and transfer a data string via modem containing information to assist the response center in acting on the request. Prior to attempting dialing of the cellular transceiver, a command or set of commands places the cellular transceiver into an unrestricted operating mode to provide the greatest probability of completing a call from the vehicle to the response center and from the response center to the vehicle.

Abstract: A vehicle user can request emergency or roadside assistance from a response center by activating a button in the vehicle. The global positioning system is used to continuously store the vehicle location. A cellular telephone network is used to contact a response center and transfer a data string via modem containing information to assist the response center in acting on the request. Predetermined information concerning system operation is stored in a non-volatile memory during an activation for diagnostic purposes. Data is written in two groups at respective times during an activation, and a status flag indicates whether both groups were successfully written to memory.

Abstract: A vehicle user can request emergency or roadside assistance from a response center by activating a button in the vehicle. The global positioning system is used to continuously store the vehicle location. A cellular telephone network is used to contact a response center and transfer a data string via modem containing information to assist the response center in acting on the request. The response center sends a termination tone to the vehicle upon satisfactory completion of the request. If the vehicle loses contact with the response center prior to receiving the termination tone, it attempts to reestablish communication with the response center.

Abstract: A vehicle user can request emergency or roadside assistance from a response center by activating a button in the vehicle. The global positioning system is used to continuously store the vehicle location. A cellular telephone network is used to contact a response center and transfer a data string via modem containing information to assist the response center in acting on the request. The vehicle installed system initiates an automatic call-in to the response center if the elapsed time since the last successful connection with the response center is greater than a predetermined time. Data is transmitted during the automatic call-in that identifies the vehicle and verifies to the response center that a particular system is operative.