An access apparatus (ZV) for a vehicle (FZ) has a vehicle-side position-determining device (PBE) for determining the position (POS1, POS2, POS3) of a mobile identification signal generator (IDG) with respect to the vehicle. In addition, said access apparatus (ZV) has a vehicle-side control device (STE) for emitting location-determining signals (LS1) to the mobile identification signal generator (IDG) for determining the position thereof. In this context, the vehicle-side control device (STE) is configured to control the frequency of the emission of the location-determining signals as a function of the position of the mobile identification signal generator with respect to the vehicle. In this way, the power consumption both in the vehicle and in the identification signal generator can be reduced on the basis of the location-dependent adaptation of the emission of the interrogation signals, without adversely affecting reliable operation of the access apparatus.