Steering-wheel antitheft device for an automobile

The device has a bolt (30) cooperated with a cam (23) such that the cam drives the bolt between locking and unlocking positions of a steering column. A return spring (40) of the bolt returns the bolt in the locking position. A movable indexer (60) is cooperated with a sensor detecting a position of the cam controlling a locking configuration of the column. Another return spring (62) of the indexer returns the indexer such that the indexer is engaged with the cam, where the springs are distinct. The indexer is slid freely in a groove provided on lateral neck of the bolt. The sensor is a hall effect sensor. An independent claim is also included for a rotation assistance module comprising an assistance motor.