Immobilizer for motor vehicle steering column

Lock (6) for theft of a motor vehicle steering column comprising: - a stator (8) comprising a stator head (16) in which is formed an opening (18), - a rotor (10) rotatably mounted by relative to the stator (8) about an axis and comprising an annular collar (26), - a cam (12) intended to be rotationally fixed to the rotor (10), - an elastic member (14) arranged between the cam ( 12) and the rotor (10) for axially biasing said rotor thrust, wherein the opening (18) is shaped for cooperation with the annular collar (26) blocks the rotation of the rotor (10) in one direction of rotation predetermined from a predetermined angular position and allows the rotation of the rotor (10) beyond the predetermined angular position by prior insertion of the rotor (10).