480 so that the startup data are transferred from the memory area of lcu 480 into the memory area of tcu 410 protocol translator program translator 400 translates a diagnostic command of the one communication protocol directly into a diagnostic command of the other communication protocol the term u201c directly u201d describes that the translation of the diagnostic command takes place immediately if the tcu does not give preference to higher priority tasks of the translation in this way there is a u201c simultaneous translation u201d so that a rapid command exchange or a rapid exchange between command and confirmation or response or the like for example between tester 470 and lcu 480 is possible so that bidirectional communication can also occur between tester 470 and lcu 480 thus it is seen that the objects of the present invention are efficiently obtained although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art which modifications are intended to be within the spirit and scope of the invention as claimed it also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting therefore other embodiments of the present invention are possible without departing from the spirit and scope of the present invention 130 tcu sends responses of the lcu back to the tester 320 tester calls function a in the tcu by means of client specific diagnostic protocol 330 tcu flash function a flashes the lcu sw into the lcu by means of ccp xcp calibration protocol 340 status feedback to the tester by means of client specific diagnostic protocol 410 tcu control unit with gateway function and protocol translator program translator 420.