Anti-theft immobilizer system and method for detecting tampering or unauthorized use of a vehicle

An anti-theft immobilizer system for a vehicle including an internal combustion engine including a sole regular maintenance access point including a hinged cover (hood), the engine including an ignition system powered by an onboard battery exclusively accessible by the hinged cover, the anti-theft engine immobilizer system comprising:

• an anti-theft vehicle immobilizer module secured to the engine ignition system's onboard battery and electrically disposed as to be an intermediary between the onboard battery and the vehicle ignition system;
• a wireless communication network;
• a mobile phone device including a software application and interface;
• a single or plurality of programmable circuit boards;
• a single sealed enclosure with internal electronic component mounting points;
• and a receiving bore to accommodate a vehicles ignition system battery electrical terminal;
• a siren;
• a single on-board power source;
• a digitally activated relay;
• an amperemeter or other type of device to measure instantaneous current;
• and an ultrasonic sensor or other type of sensor with a capability to measure a distance in real time, the sensor operatively mounted on the onboard battery and communicatively coupled to a programmable control module, the sensor configured to detect tampering by measuring a straight and uninterrupted distance between the hinged cover and a designated permanent static reference object located within the regular maintenance access point area.