A method for detecting a user's intention to lock or to unlock a door of a motor vehicle, using a detection device integrated into a handle of said door, comprising an ultra high-frequency antenna for exchanging an identifier with a “hands-free” access device carried by the user, one face of which is situated close to a second outer surface or respectively a first outer surface of the handle, an ultra-high-frequency antenna matching circuit, an ultra-high-frequency signal generator and an electronic unit, said method comprising:
- measuring a power of a signal transmitted by the ultra-high-frequency signal generator to the ultra-high-frequency antenna and a power of a signal reflected from the ultra-high-frequency antenna to the ultra-high-frequency signal generator,
- determining a parameter representative of a ratio between the power of the transmitted signal and the power of the reflected signal,
- comparing the parameter with a predetermined threshold, and
- detecting the intention to lock or respectively to unlock when the parameter is higher than or lower than the predetermined threshold.