Abstract: A method for detecting malfunctions in a motor vehicle, in which data words formed in subassemblies (sensors or components) upon detection of a malfunction therein are read by an analysis unit. The data words are also formed by the subassemblies when a malfunction detected by a peripheral subassembly is not traceable to said subassembly. Functional chains are determined in a device on the basis of the malfunctions detected by the subassemblies and represented by the corresponding data words. The functional chains contain all the sources of error related to the malfunctions. A list of test steps is drawn up in the device and stored at memory locations provided for this purpose. The test steps allow checking all the sources of error, and the functional chain is completely checked after execution of the test steps.