A method for defining a reference position (θ ref) of power steering, said power steering comprising at least one movable steering member whose position varies according to the orientation given to the steering, said method comprising: - a tracking step (a), during which an index pulse (T1, T2) is generated when the movable steering member passes through a predetermined position, called « indexed position », - a processing step (b), during which the index pulse is analyzed to detect a leading edge (F1, F2) and/or a trailing edge (F3, F4) therein, - a characterization step (c) during which, a value called « edge position » value (θ F1, θ F2, θ F3, θ F4), which is representative of the position that the movable steering member occupies when said edge (F1, F2, F3, F4) takes place, is associated to the leading or trailing edge (F1, F2, F3, F4), identified during the processing step (b), said method being characterized in that - the tracking (a), processing (b) and characterization (c) steps are repeated, on the one hand, for a first index pulse which is generated when the movable steering member crosses the indexed position along a first displacement direction, and, on the other hand, a second index pulse which is generated when said movable steering member crosses this same indexed position along a second displacement direction, opposite to the first displacement direction, so as to acquire respectively, on the one hand, a first edge position (θ F1), which corresponds to a first edge generated in the first displacement direction, and on the other hand a second edge position (θ F2), which corresponds to a second edge which is generated along the second displacement direction and which is of the same nature, leading or trailing, as the first edge, and in that said method includes a step (d) of calculating a reference position (θ ref), during which, from the first edge position (θ F1) and the second edge position (θ F2), a reference position (θ ref) of the power steering is calculated. - a tracking step (a), during which an index pulse (T1, T2) is generated when the movable steering member passes through a predetermined position, called « indexed position », - a processing step (b), during which the index pulse is analyzed to detect a leading edge (F1, F2) and/or a trailing edge (F3, F4) therein, - a characterization step (c) during which, a value called « edge position » value (θ F1, θ F2, θ F3, θ F4), which is representative of the position that the movable steering member occupies when said edge (F1, F2, F3, F4) takes place, is associated to the leading or trailing edge (F1, F2, F3, F4), identified during the processing step (b), - the tracking (a), processing (b) and characterization (c) steps are repeated, on the one hand, for a first index pulse which is generated when the movable steering member crosses the indexed position along a first displacement direction, and, on the other hand, a second index pulse which is generated when said movable steering member crosses this same indexed position along a second displacement direction, opposite to the first displacement direction, so as to acquire respectively, on the one hand, a first edge position (θ F1), which corresponds to a first edge generated in the first displacement direction, and on the other hand a second edge position (θ F2), which corresponds to a second edge which is generated along the second displacement direction and which is of the same nature, leading or trailing, as the first edge,