The invention provides a method for evaluating the self-diagnostic system of a controller in a motor vehicle having a control panel with a push-button switch with automatic return, and additional input elements and having a signalling element which is suitable for emitting a flashing code. In order to emit a structured flashing code of fault numbers, the range of possible faults which can be diagnosed is divided into fault classes, the faults within a fault class being assigned fault numbers which can be emitted, separated on the basis of fault classes, by flashing code. A specific fault class is selected by the operator by setting the input elements to a specific position combination which is assigned to the fault class, and operation of the push-button switch (for example, the recirculation push-button in the case of a heating controller).