The paper describes relevance of the issue of ensuring reliable operation of vehicles for providing the required level of economic efficiency and safety of transportations via transport systems. Systems analysis method is used for solving the scientific problem. The place of vehicles is defined in the general classification of technical systems on the basis of systems analysis. The study proposes to divide the criteria of operational efficiency in accordance with the groups of properties of technical objects and shows their interrelation. As a result of the study, the generalized structure of integrated complexes of on-board equipment (ICOE) of vehicles is formed. Analysis of ICOE properties and their effect on the complex reliability is performed from the standpoint of systems approach is performed. Theoretical substantiation is provided for the necessity and the possibility of implementing the principles of survivability and fault tolerance of ICOE to ensure their effective use. The application of mutual control structures for the organization of on-board computer system diagnostics as a central part of ICOE is substantiated.