The invention relates to a system for controlling the operation of presence-detection devices and to the implementation method thereof. The inventive system comprises: external presence detection means which are used to detect objects entering a determined surveillance area outside a motor vehicle and which are powered by a power source, an electronic system, and means which are used to detect the state of a closure device belonging to a door of said vehicle and which are associated with and co-operate with the electronic system in order to control the power source. Optionally, internal presence detection means and inclination detection means, which are included in the system, can be taken into account when said control operation is being performed. The inventive system also varies the surveillance area and adapts same as a function of the inclination of the vehicle in relation to the ground plane. The invention also relates to a method which uses the inventive control system.