There is described a method for checking the presence of an ID transmitter in the passenger compartment of a motor vehicle, wherein the ID transmitter for wireless access control for wireless activation of an engine starting switch is used and in the interior of the vehicle at least one antenna for emitting a presence query signal present is. The method is characterized in that with the engine running, the transmission of presence query signals via the at least one interior antenna of at least one state sensor is made only after the evaluation of information, the state (open / closed) for a vehicle door, a trunk lid, a windows, a sunroof or a convertible determined. The procedure produces an extension of the battery in the ID transmitter life.