The application of on-board diagnostics systems for assessing the technical state of automotive vehicles

This article presents the results of investigations regarding the use of on-board diagnostic systems to assess the technical state of automotive vehicles, and the possibilities of early fault detecting. The examinations were carried out in order to establishifit is possible to evaluate the level of compatibility between diagnostic test units and on-board diagnostic systems in over three hundred models of vehicles which were produced by different manufactures. The investigations concerning the influence of examination conditions, the type of faults and the vehicle age upon the results and reliability of diagnostic tests were carried out. The suitability of fault codes which were recorded in the memory of diagnostic system while the vehicle was operating have been determined as far as the recognition of the type of faults is concerned. Additionally, the examinations of engine on a test stand were carried out as well. Sensitivity of diagnostic systems was tested regarding the changes of work parameters of the engine. The faults of engine were deliberately provoked and were examined at the early stage by on-board diagnostic systems. The test results show that there is a necessity of elaborating new diagnosing methods enabling to find damages regarding safety in road traffic.