Driving a component of a vehicle by using a portable user identification device for the vehicle and an user identification unit of the vehicle, whereat a controller evaluates an identifying signal sent by a transmitter of the portable user identification device to a receiver of the user identification unit and the controller drives the component of the vehicle according to the evaluation of the identifying signal. In order to provide a higher level of security by driving a component of a vehicle by using a portable user identification device for a vehicle, to a point of time tn a position of the portable user identification device relative to a position of the portable user identification device to a point of time tn=tl, to which the portable user identification device is departing from the vehicle, is determined and stored in a memory on a regular basis.