A gear motor, in particular for a wiper system, comprising: - a brushless direct current electric motor comprising: - a rotor, - a stator having electromagnetic excitation coils for the rotor, - a device for determining the angular position of the rotor relative to the stator, - either a single Hall effect sensor or two Hall effect sensors (27a, 27b) angularly offset relative to one another, the Hall effect sensor or sensors (27, 27a, 27b) being associated with a control magnet (29, 29', 29", 29''') secured in rotation to the rotor, and connected to the device for determining the angular position of the rotor, - a control unit configured to generate control signals for powering the electromagnetic excitation coils of the stator as a function of the angular position of the rotor determined by the device for determining the angular position of the rotor, - a speed-reducing mechanism linked on one side to the rotor of the electric motor and on the other side to an output shaft intended to be linked to an external mechanism, in particular a wiper system, the speed-reducing mechanism having a predefined reduction ratio and, - an output angular position sensor configured to measure the angular position of the output shaft connected to the device for determining the angular position of the rotor and is configured to transmit a signal corresponding to the measured angular position of the output shaft characterized in that said device for determining the angular position of the rotor is configured to determine the position of the rotor relative to the stator on the basis of the transmitted signal by taking into account the predefined reduction ratio of the speed-reducing mechanism, and to correct the angular measurement from the output angular position sensor on the basis of the signal from the Hall effect sensor or sensors (27, 27a, 27b). - a brushless direct current electric motor comprising: - a rotor, - a stator having electromagnetic excitation coils for the rotor, - a device for determining the angular position of the rotor relative to the stator, - either a single Hall effect sensor or two Hall effect sensors (27a, 27b) angularly offset relative to one another, the Hall effect sensor or sensors (27, 27a, 27b) being associated with a control magnet (29, 29', 29", 29''') secured in rotation to the rotor, and connected to the device for determining the angular position of the rotor, - a control unit configured to generate control signals for powering the electromagnetic excitation coils of the stator as a function of the angular position of the rotor determined by the device for determining the angular position of the rotor, - a speed-reducing mechanism linked on one side to the rotor of the electric motor and on the other side to an output shaft intended to be linked to an external mechanism, in particular a wiper system, the speed-reducing mechanism having a predefined reduction ratio and, - an output angular position sensor configured to measure the angular position of the output shaft connected to the device for determining the angular position of the rotor and is configured to transmit a signal corresponding to the measured angular position of the output shaft