In this paper, the features of a diagnostic measurement setup have been determined. The purpose of the setup was registration of diagnostic signals taken from an electronically controlled gasoline-powered engine. Special attention has been paid to the presentation of the features of an analog-digital converter card used, as well as to the possibility of its practical use. Another important aspect is the design and programming of computer software dedicated for action along with the setup. The results of the work have been presented using the example of the engine's microprocessor control module. A diagnostic analysis was conducted, as a result of which sets of the functional elements of the object and its diagnostic signals were determined. Also, the methodology of the diagnostic examination of the technical system was presented. The result was a functional and diagnostic model, which constituted the basis for initial diagnostic information, which is provided by the sets of information concerning the elements of the basic modules and their output signals.