ACCESS AND START/DRIVE AUTHORIZATION SYSTEM FOR A MOTOR VEHICLE

摘要

The invention relates to an access and start/drive authorization system for a motor vehicle having a portable transponder and a control device mounted in the motor vehicle. Said devices interact by means of question-answer dialogues using matching code information and release or block access to, starting of and driving the motor vehicle. Both authorization systems may be optimally differentiated provided that additional information (Coz, Cosf) characterizing the type of authorization verification - access authorization or start/drive authorization - is supplied to the release signals sent by the control device (SG) and that, depending on said additional information (Coz or Cosf), the transponder (TP) uses an inductive transmission channel (S1-E1) and a more powerful transmission channel (S1-E2) for the access question-answer dialogue (ZD) and only the inductive transmission channel (S1-E1) for the start/drive question-answer dialogue (SFD).