Anti-theft device for a motor vehicle, comprising a sender portable, a control apparatus and a transponder portable

摘要

An anti-theft device comprises a key (10) which, when it is actuated, generates a start signal, which triggers a dialogue question - response between a transponder (14) placed in the key (10) and a control device (21) located in the motor vehicle (20). In order that the starting signal arrives in a reliable manner to the motor vehicle (20), it is transmitted to several times during a predetermined period of time, the code signal in question also being then sent to several times with the key (10).