ON-BOARD DIAGNOSTICS FOR EMISSION CONTROL SYSTEMS
Joseph M. Kotzan · SAE technical papers on CD-ROM/SAE technical paper series · 1991
The introduction of Electronic Controls on engines in the late 1970's brought about many changes in the auto industry. One major change was the inclusion of a sophisticated diagnostic system, resident in the controller that allowed it to monitor itself and the system it controls. General Motors introduced On-Board Diagnostics on all of its closed-loop fuel control systems in 1980 and has continued to enhance and refine the diagnostic system each succeeding year. This paper presents a brief history of On-Board Diagnostics, the strategy behind the diagnostics and the benefits of diagnostics to maintaining control of vehicle emissions and aiding in the service process.