Method for activating a vehicle function from a portable access device and associated activation module

An activation module, intended to be fitted to a motor vehicle for the purpose of activating a function of the vehicle from a portable access device carried by a user, the activation module comprising:

• a single coil;
• a first controller for a device for detecting pressure from a hand of the user;
• a second controller for a near-field communication device having a communication frequency that is capable of communicating with the portable access device;
• a selector, connected to the single coil, having two positions:
• a first position in which the selector connects said single coil to the first controller and disconnects the single coil from the second controller in order to constitute the pressure detection device;
• a second position in which the selector connects said single coil to the second controller and disconnects the single coil from the first controller in order to constitute the near-field communication device;
• a target having a void, said target being located facing the single coil and capable of moving with respect to the single coil;
• an impedance adjuster that is connected to the target;
• a third controller for the selector.