Vehicle anti-theft system using second key means

Abstract

A vehicle anti-theft system, comprising a mechanical key unit, an electronic key unit, and a control unit allowing operation of a motor vehicle only when both the mechanical key unit and the electronic key unit are operataed by a mechanical key and a keyboard, respectively. To permit operation of the motor vehicle even when the second electronic key unit has become unable to operate normally, there is provided a second electronic or mechanical key unit which can be operated manually or by means of the mechanical key. To discourage unauthorized operation of the motor vehicle, the second key unit requires entry of coded data or insertion of a mechanical key into a key switch provided in a poorly accessible part of the vehicle body. In this way, an authorized person can operate the motor vehicle even when the electronic key unit is unable to function normally without increasing the risk of an unauthorized person operating the motor vehicle.

Dependencies are inferred from the claim text.