Automatic vehicle theft prevention system

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 mobile radio frequency identification (RFID) data carrier separate from said ignition key for detecting said excitation signal and radiating said return signal, said mobile RFID data carrier including a memory element for storing an identification code for said mobile RFID data carrier, said mobile RFID data carrier modulating said excitation signal to produce said return signal containing said identification code;
• a controller in communication with said antenna for detecting said identification code in said return signal;
• a relay actuated by said controller to one of an enable mode and a disable mode, said relay being actuated to said enable mode to enable said ignition system in response to detection of said identification code, and said relay being actuated to said disable mode to disable said ignition system whenever said controller fails to detect said identification code;
• and 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;
• an override switch in communication with an input of said latching relay 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;
• and an indicator in communication an output of said override switch and energized when said override switch is activated.