Patent ID: 7064651

Claim:
An automatic vehicle theft prevention system for selectively enabling an ignition system of a vehicle, said ignition system being operable using an ignition key, and said system comprising: an interrogator circuit including a signal generator for generating an excitation signal and an antenna coupled to said signal generator for radiating said excitation signal and receiving a return signal; a transponder circuit separate from said ignition key for detecting said excitation signal and radiating said return signal, said transponder circuit modulating said excitation signal to produce said return signal containing an identification code for said transponder circuit; a controller in communication with said antenna for detecting said identification code in said return signal; a relay actuated to an enable mode by said controller when said controller detects said identification code, said relay being actuated to enable said ignition system; wherein said ignition system includes an ignition switch activated by said ignition key, and said system further includes a latching relay actuated in response to a momentary actuation of said relay when said controller detects said identification code, said latching relay being adapted to remain latched until said ignition switch is deactivated; further comprising an override switch in communication with an input of said latching relay wherein activation of said override switch causes said latching relay to be latched to continuously enable said ignition system; and wherein activation of said override switch causes said latching relay to remain latched to continuously enable said ignition system only following actuation of said latching relay by said relay.