Method for actuating a reversible belt pretensioner

H Method for actuating a reversible belt pretensioner for pretensioning a belt webbing, the belt pretensioner having a drive which acts on the belt reel, and the seat belt having, as a belt extraction lock, a locking device which acts on the belt reel in the unwinding direction and whose locking can be released only if the belt reel is rotated through a specific angle of rotation in the winding-on direction. After the triggering of the belt pretensioner, the drive of the belt pretensioner for opening the locking device is actuated in an opening mode such that firstly, in a winding-on phase, the belt reel rotates through the specific angle of rotation in the winding-on direction. In a subsequent holding phase, the drive of the belt pretensioner is actuated for a predefinable holding time Tsuch that the belt reel is held in its angular position.