Anti-theft system for a vehicle

Abstract

A vehicular anti-theft system, comprising: a mechanical key switch which can be turned with a matching mechanical key between a first angular position suitable for receiving the mechanical key therein and corresponding to an inoperative state of the vehicle and a second angular position corresponding to an operative state of the vehicle; electronic code matching circuit for detecting an electronic code signal transmitted from a transmitter incorporated in a part of the mechanical key; a control circuit which enables the vehicle when the mechanical key switch is turned with a matching key to the second angular position and the electronic code matching circuit has detected the matching code signal from the transmitter; a trigger circuit which acts upon the control circuit into detecting the matching code signal transmitted from the transmitter; wherein the trigger circuit is activated when the angular position of the mechanical key switch is set to a certain position preceding the position for starting the vehicle. Thereby, the process of code matching is performed before the ignition key switch is turned to the position for starting the vehicle, and the time required to start the vehicle is not increased by this code matching process.