Locking system especially for ignition lock of e.g. motor vehicle

摘要

The locking system includes a key (22) a code transmitted to a comparison unit (6) and compared with a stored code. If the result of the comparison is positive, at least an operation function of an apparatus is released which is equipped with the locking system. An additional and removable key (28) is provided at the key. A reading unit (26) is provided which determines the existence of the additional key. At least one operation function is released only when the additional key exists. Preferably, the additional key has an own coding which is read by the reading unit and compared with the stored coding. The one operation function is only released if the result of the comparison is positive. The additional key has a key web with mechanical coding.