A diagnostic method for a vehicle component of a vehicle, an operating parameter of the vehicle component being detected during an operation of the vehicle and a status message corresponding to a status of the vehicle component being transmitted to a vehicle-external server as a function of the detected operating parameter for an analysis of the status message, a message based on the analysis of the status message being transmitted to a receiving device. The invention furthermore relates to a corresponding diagnostic device, a corresponding diagnostic system, as well as a computer program is also described.