Magnetic speed sensor with increased resolution

A method for increasing a resolution of a magnetic sensor for an internal combustion engine of a motor vehicle, a target comprising an alternating succession of teeth and of recesses being associated with an element driven by the internal combustion engine and the magnetic-field sensor detecting magnetic-field variations induced by a passage of the teeth of the target in proximity to the sensor, by generating a magnetic signal, then periodically delivering an electrical output signal, called the synchronization signal, in a synchronization voltage range, to an electronic control unit with a view to synchronizing the internal combustion engine, the electrical synchronization signal comprising successive, spaced-apart crenels, one of the rising or falling edges of which corresponds to a beginning or an end of the respective passage of a tooth of the target, which occurs at a respective angle of rotation of the element of the engine, characterized in that the synchronization voltage range is interposed between an upper voltage modulation range above and a lower voltage modulation range below the upper and lower voltage of the synchronization range, respectively, the electrical signal in each of the lower and upper modulation ranges being modulated so as to comprise additional crenels, which are supplementary to the crenels of the synchronization signal, corresponding to periodic clock crenels with a period dependent on engine speed, an angle of rotation being identified by one of the rising or falling edges of each additional crenel.