A keyless access system for a motor vehicle, which includes a portable signal generator for access to one or more doors or flaps of the motor vehicle, wherein the signal generator transmits an enable signal to a receiver unit, mounted on the motor vehicle, by a short-range radio link. The receiver unit permits access to one or more doors or flaps if it is determined that the enable signal is valid and a distance criterion which represents a distance between the signal generator and the motor vehicle is satisfied. The distance criterion results from a comparison of a weighted reception field strength of the short-range radio link between the signal generator and the receiver unit with a threshold value.