Abstract: A locking device for use in motor-vehicle steering systems, the locking device having a blocking mechanism by which a pitman arm shaft can be locked, a steering wheel of the motor vehicle can be prevented from rotating and vehicle wheels of the motor vehicle can be prevented from being turned or steered. The blocking mechanism includes two end positions, one of which is unlocked and one of which is locked, and is electromechanically operable. An electromagnet causes concentric external gear teeth of the pitman arm shaft to mesh with internal gear teeth of an axially movable and radially non-rotatable locking ring so that the pitman arm shaft is not rotatable in the locked state.

Abstract: A method for preventing misuse of a transponder left inside a vehicle, which is part of a keyless vehicle access system and coacts with a control system for access and driving authorization located in the vehicle. The control system emits, in response to a locking command, a check signal by way of which it is ascertained whether transponders are still located in the vehicle interior after locking. Transponders which are detected as being located in the vehicle interior after locking are recorded in a memory associated with the control system. Upon a subsequent legitimate access to the vehicle, transponders that are not again detected in the interior are inhibited.