Method of testing an electronic control system

A method for testing at least one electronic control system (1) is showed and described, wherein, the control system (1) connects with testing device(3) by a data channel (2), the testing device calculates at least one environmental model (4) which exports the environmental model data to the control system (1) by the testing device (3), receives the data of the control system from the control system on the data channel (2) and interacts with the control system (1). The method of the invention overcomes the fault of the existing method in the technology, which includes executing at least one test model (5) for influencing the environmental model (4) and/or calculating and/or electronic control system (1) of the environmental model (4), the test model (5) or these test models (5a, 5b) executed functionally independent of the environment model (4) and on a testing operation that is in synchronization with the environment model (4).