The system uses a key, a lock, connecting lines between lock and engine, and an extra disabling device. The vehicle door lock has a device to produce a door signal from an electronic key. Only with correct reception and decoding of the door signal is the door lock opened. A second key (6) may also be electronic and may be identical to the door key. The second key cooperates with a second receiver and decoder in a second lock (7). The decoder (10) is incorporated in the engine's fuel-pump circuit and is connected to the receiver (17) via connection lines (8).
