History of Science and Engineering Annotation << Back THE HISTORY OF DEVELOPMENT OF SYSTEM THE CAR DIAGNOSTICS OBD-II A.S. Dadilov In this article, the author has carried out a historical analysis of the development of the diagnostic system for vehicles equipped with electronic systems, which is due to the need to control the exhaust gases of the vehicle. The problems of pollution of the environment with exhaust gases from cars, due to their constantly increasing number, especially in large cities, are forcing the governments of countries to tighten requirements for emissions. At the same time, it is necessary to constantly improve and develop the vehicle diagnostics system in order to identify malfunctions that affect the level of exhaust gases. Especially considering the huge variety of car models produced around the world and their design features. All this required the development and implementation of uniform requirements for the vehicle diagnostics system. Therefore, the car diagnostic system has come a long way in its development and continues to be constantly improved. Keywords: car diagnostics, exhaust gases, diagnostic connector, error codes, control unit, fault indicator. DOI: 10.25791/intstg.3.2021.1262 Pp. 37-44.