A method for detecting a decreasing performance of at least one sensor is described, in particular in a vehicle, wherein a setpoint trajectory of the vehicle is calculated, the setpoint trajectory is driven by the vehicle or is simulated by an artificial intelligence, the actual trajectory driven by the vehicle or the simulated trajectory is compared with the setpoint trajectory, a performance of the at least one sensor is tested by the control unit if a deviation of the actual trajectory or the simulated trajectory from the setpoint trajectory is determined, in which test each sensor of the vehicle is alternately deactivated and with the aid of at least one alternative sensor the setpoint trajectory is driven by the vehicle or is simulated by an artificial intelligence. Furthermore, a control unit, a computer program and a machine-readable storage medium are described.