A method for testing at least one electronic control device as a virtual control device on a simulator having at least one simulator computing unit, the electronic control device comprising a hardware configuration having at least one computing unit and an external interface for exchanging data, and comprising a software configuration associated with the hardware configuration, the software configuration comprising an internal functionality and an external interface functionality, the electronic control device being mapped onto the virtual control device by adopting the internal functionality of the software configuration of the electronic control device as the internal functionality of a software configuration of the virtual control device and by replacing the external interface functionality of the electronic control device with a data transfer functionality of a software configuration of the simulator computing unit, the software configuration of the virtual control device being translated into executable code for the simulator computing unit and executed on the simulator, characterized in that the hardware configuration of the electronic control device comprises at least one first computing unit (6a1) and a second computing unit (6a2) of different types, and in that the software configuration of the electronic control device comprises at least internal functionalities (7a1, 7a2) for the first computing unit (6a1) and the second computing unit (6a2), wherein at least the internal functionality (7a1) of the first computing unit (6a1) invokes an internal function (f_i) of the internal functionality (7a2) of the second computing unit (6a2), and in that a description of the hardware configuration and the software configuration of the electronic control device, including the association of the internal functionalities (7a1), (7a2) of the software configuration of the electronic control device with the computing units (6a1), (6a2) of the electronic control device, and the internal functionalities (7a1, 7a2) of the computing units (6a1, 6a2) of the electronic control device themselves are provided, and in that, by evaluating the description of the electronic control device, each computing unit (6a1, 6a2) of each type of electronic control device having an associated internal functionality (7a1, 7a2) is mapped onto a virtual sub-computing unit (13.1, 13.2) of a corresponding type, wherein the internal functionality (7a1, 7a2) of the electronic control device of the mapped computing unit (6a1, 6a2) is converted into an internal functionality (8a1, 8a2) of the virtual sub-computing unit (13.1, 13.2) able to be executed on the simulator computing unit, and in that the evaluation of the provided internal functionalities (7a1, 7a2) of the first computing unit (6a1) of the electronic control device and of the second computing unit (6a2) of the electronic control device is used to determine which computing units (6a1, 6a2) of the electronic control device are in data exchange with each other by accessing an internal function (f_i) of another computing unit (6a1, 6a2) of the electronic control device and the accesses to internal functions (f_i) of another computing unit (6a1, 6a2) at the virtual control device are replaced by a data transfer functionality of the software configuration of the simulator computing unit. the hardware configuration of the electronic control device comprises at least one first computing unit (6a1) and a second computing unit (6a2) of different types, and in that the software configuration of the electronic control device comprises at least internal functionalities (7a1, 7a2) for the first computing unit (6a1) and the second computing unit (6a2), wherein at least the internal functionality (7a1) of the first computing unit (6a1) invokes an internal function (f_i) of the internal functionality (7a2) of the second computing unit (6a2), and in that a description of the hardware configuration and the software configuration of the electronic control device, including the association of the internal functionalities (7a1), (7a2) of the software configuration of the electronic control device with the computing units (6a1), (6a2) of the electronic control device, and the internal functionalities (7a1, 7a2) of the computing units (6a1, 6a2) of the electronic control device themselves are provided, and in that, by evaluating the description of the electronic control device, each computing unit (6a1, 6a2) of each type of electronic control device having an associated internal functionality (7a1, 7a2) is mapped onto a virtual sub-computing unit (13.1, 13.2) of a corresponding type, wherein the internal functionality (7a1, 7a2) of the electronic control device of the mapped computing unit (6a1, 6a2) is converted into an internal functionality (8a1, 8a2) of the virtual sub-computing unit (13.1, 13.2) able to be executed on the simulator computing unit, and in that the evaluation of the provided internal functionalities (7a1, 7a2) of the first computing unit (6a1) of the electronic control device and of the second computing unit (6a2) of the electronic control device is used to determine which computing units (6a1, 6a2) of the electronic control device are in data exchange with each other by accessing an internal function (f_i) of another computing unit (6a1, 6a2) of the electronic control device and the accesses to internal functions (f_i) of another computing unit (6a1, 6a2) at the virtual control device are replaced by a data transfer functionality of the software configuration of the simulator computing unit.