A method for sensorless detection of a mechanical motor load applied to the motor shaft of a stepper motor, the stepper motor being operated in a voltage-based operating mode in which a nominal coil current is generated by applying a predetermined coil voltage (Us) to the coil, the coil being connected in a bridge branch of a bridge circuit formed from a first to fourth semiconductor switch (S1,...S4), and the predetermined coil voltage (Us) being applied to the coil with a variable duty cycle by switching the semiconductor switch in the form of at least one PWM voltage (U, U), wherein the motor load is detected in the form of a load indicator signal which represents a phase shift between a zero crossing of the predetermined coil voltage (Us) and the next zero crossing of the coil current (Icoil) generated thereby, characterized in that a zero crossing of the coil current (Icoil) is defined comprising the following steps: - by means of a first comparator, the inputs of which are connected to both terminals of the coil, a logic zero-crossing signal (I 0) is generated, which indicates a polarity of a voltage dropping across the internal resistances of two semiconductor switches due to the coil current, - a said logic coil voltage zero signal (U 0) is generated, when in those time intervals (tm) in which the PWM voltage (U, U) applied to the coil is zero, a polarity change occurs in a voltage dropping across the internal resistances of the semiconductor switches due to the coil current compared to the preceding measurement, - an instantaneous phase angle difference dPhi = Phi modulo 180° is generated on the basis of an instantaneous phase angle (Phi) of the given coil voltage (Us), and - a load indicator signal is output when, as a first condition, the logic zero-crossing signal (I 0) indicates a polarity change of the voltage dropping across the internal resistors of the semiconductor switches and when, as a second condition, the coil voltage zero-crossing signal (U 0) indicates that the PWM voltage (U(A 1), U(A 2)) applied to the coil is zero. wherein the motor load is detected in the form of a load indicator signal which represents a phase shift between a zero crossing of the predetermined coil voltage (Us) and the next zero crossing of the coil current (Icoil) generated thereby, characterized in that a zero crossing of the coil current (Icoil) is defined comprising the following steps: - by means of a first comparator, the inputs of which are connected to both terminals of the coil, a logic zero-crossing signal (I 0) is generated, which indicates a polarity of a voltage dropping across the internal resistances of two semiconductor switches due to the coil current, - a said logic coil voltage zero signal (U 0) is generated, when in those time intervals (tm) in which the PWM voltage (U, U) applied to the coil is zero, a polarity change occurs in a voltage dropping across the internal resistances of the semiconductor switches due to the coil current compared to the preceding measurement, - an instantaneous phase angle difference dPhi = Phi modulo 180° is generated on the basis of an instantaneous phase angle (Phi) of the given coil voltage (Us), and - a load indicator signal is output when, as a first condition, the logic zero-crossing signal (I 0) indicates a polarity change of the voltage dropping across the internal resistors of the semiconductor switches and when, as a second condition, the coil voltage zero-crossing signal (U 0) indicates that the PWM voltage (U(A 1), U(A 2)) applied to the coil is zero. - by means of a first comparator, the inputs of which are connected to both terminals of the coil, a logic zero-crossing signal (I 0) is generated, which indicates a polarity of a voltage dropping across the internal resistances of two semiconductor switches due to the coil current, - a said logic coil voltage zero signal (U 0) is generated, when in those time intervals (tm) in which the PWM voltage (U, U) applied to the coil is zero, a polarity change occurs in a voltage dropping across the internal resistances of the semiconductor switches due to the coil current compared to the preceding measurement, - an instantaneous phase angle difference dPhi = Phi modulo 180° is generated on the basis of an instantaneous phase angle (Phi) of the given coil voltage (Us), and - a load indicator signal is output when, as a first condition, the logic zero-crossing signal (I 0) indicates a polarity change of the voltage dropping across the internal resistors of the semiconductor switches and when, as a second condition, the coil voltage zero-crossing signal (U 0) indicates that the PWM voltage (U(A 1), U(A 2)) applied to the coil is zero.