I - Immobiliser
Immobiliser - A major security device to prevent thieves from stealing a car even if they gain entry. An electronic immobiliser is part of the engine control unit (ECU), and prevents the car from being started unless it recognises signals from a transponder in the key.
Every new car in the UK has to have an electronic immobiliser fitted by law. You can also protect your car with a mechanical immobiliser such as a steering lock.