- A method for determining a relative angular position of a first part with respect to a second part about an axis of rotation, the method comprising: - equipping the first part with a magnetized body, in the shape of an angular cylindrical sector of revolution about the axis of rotation, having a front envelope surface which is an outer cylindrical surface of revolution, and with diametrical magnetization; - equipping the second part with a first measurement cell at a first measurement point and with a second measurement cell at a second measurement point, each measurement cell delivering at least two electrical signals respectively representative of a primary component ( B x1, B x2) and a secondary component (B y1, B y2) of the magnetic field created by the magnetized body at the measurement point ( P1, P2) of the considered cell ( 10, 11), respectively along a primary measurement axis ( x) and a secondary measurement axis ( y) which are orthogonal together and orthogonal to the axis of rotation; - arranging the first measurement point of the first measurement cell and the second measurement point of the second measurement cell at equal distance from the axis of rotation and in positions spaced by a non-zero fixed angle (α 2 - α 1) strictly less than 90 degree angle about the axis of rotation; characterized in that: - the first and second measurement cells ( 11, 12) are arranged on the second part such that the primary measurement axes ( x) of the first and second measurement cells are parallel to each other, and that the secondary measurement axes ( y) of the first and second measurement cells are parallel to each other; - during a relative displacement between the measurement cells ( 11, 12) on the one hand and the magnetized body on the other hand, the measurement cells ( 11, 12) move relatively facing the front envelope surface of the magnetized body; - the method determines a value representative ( θ) of the relative angular position between the two parts by determining a raw angle ( γ) whose tangent is a function of a ratio between on the one hand the difference of the secondary components (Δ B y) and on the other hand the difference of the primary components (Δ B x), measured by the two cells ( 11, 12) for a given relative angular position ( θ). - the measuring points ( P1, P2) of the first and second cell ( 11, 12) are arranged in the same plane perpendicular to the axis of rotation, this plane being coincident with the magnet body body in the axial direction of the axis of rotation. - equipping the first part with a magnetized body, in the shape of an angular cylindrical sector of revolution about the axis of rotation, having a front envelope surface which is an outer cylindrical surface of revolution, and with diametrical magnetization; - equipping the second part with a first measurement cell at a first measurement point and with a second measurement cell at a second measurement point, each measurement cell delivering at least two electrical signals respectively representative of a primary component ( B x1, B x2) and a secondary component (B y1, B y2) of the magnetic field created by the magnetized body at the measurement point ( P1, P2) of the considered cell ( 10, 11), respectively along a primary measurement axis ( x) and a secondary measurement axis ( y) which are orthogonal together and orthogonal to the axis of rotation; - arranging the first measurement point of the first measurement cell and the second measurement point of the second measurement cell at equal distance from the axis of rotation and in positions spaced by a non-zero fixed angle (α 2 - α 1) strictly less than 90 degree angle about the axis of rotation; - the first and second measurement cells ( 11, 12) are arranged on the second part such that the primary measurement axes ( x) of the first and second measurement cells are parallel to each other, and that the secondary measurement axes ( y) of the first and second measurement cells are parallel to each other; - during a relative displacement between the measurement cells ( 11, 12) on the one hand and the magnetized body on the other hand, the measurement cells ( 11, 12) move relatively facing the front envelope surface of the magnetized body; - the method determines a value representative ( θ) of the relative angular position between the two parts by determining a raw angle ( γ) whose tangent is a function of a ratio between on the one hand the difference of the secondary components (Δ B y) and on the other hand the difference of the primary components (Δ B x), measured by the two cells ( 11, 12) for a given relative angular position ( θ). - the measuring points ( P1, P2) of the first and second cell ( 11, 12) are arranged in the same plane perpendicular to the axis of rotation, this plane being coincident with the magnet body body in the axial direction of the axis of rotation.