Abstract: The document proposes a method for communication between a plurality of local applications and a diagnostic application in a motor vehicle, where data are transmitted from the local applications to the diagnostic application using a transmission medium, and a corresponding communication module having the steps of event-oriented provision of the data by the local applications, acceptance of the data by a communication module when initiated by the event-oriented provision of the data, management and conditioning of the data by the communication module, and transfer of the conditioned data from the communication module to the central application, with the conditioning of all the data accepted from the local applications, within the communication module, comprising data formatting into a data format which is determined by the central application. The method and the communication module are particularly suitable for performing an onboard system diagnosis in motor vehicles.