This paper considers an approach to organize system diagnosis using a common control testing and 14 subsets composed of four additional checks for each “faulty” subsystem. We suggest a way to construct the subset of diagnostic checks that yields uniform check syndromes of the components with the same indexes in any faulty subsystem. We note that the required accuracy of diagnosis is guaranteed by the difference of check syndromes in any faulty subsystem. An example illustrates application of an algebraic-logical method to decode the results of checks.