Abstract
One of the methods to reduce emission of toxic components is continuous control over engine elements that are directly or indirectly responsible for level of emission of these components. Introduction of these requirements caused creation of the self-diagnostic definition and utilising innovation definition self-diagnostic:
Self-diagnostic system comparing value of signals from circuit of electronic control device with control values. If the real signal value does not comply with control value, the memory of the control devices records the error code.
The first rules of on board diagnostic were published in 1981. The standard had been improved in the next years, until the condition of today and also in the future, which result is presently used OBD II (On Board Diagnostic II) system, and in the close future - OBD III (On Board Diagnostic III).
On-board diagnostic system OBD II is present in most passenger and utility vehicles in USA; the idea originated on the turn of 70-ties and 80-ties. It was dictated by the willingness to control engine functions and to diagnose related subassemblies.
All the diagnostic devices have been designed according to main goal of the OBD (On Board Diagnostic) standard, i.e.: one connector one cable one device all diagnostic data now and in the future.
OBD II has more ability than the ever before to know what is going on inside an engine. The main reason is the increased emission output when something goes astray, but more important to protect catalytic converter from being damaged by excessive hyrocarbon or carbon monoxide. Due to this, new area are monitored, including catalytic converter conversion efficiency and crankshaft speed to determine engine misfires.
Co-ordinated works on assimilation and implementation of the OBD II (EOBD) system in Poland began in the Motor Transport Institute (ITS Motor Transport Institute) in the beginning of year 1999. These works were partially financed by the Committee of Scientific Researches. Appreciating the technology of OBD for environment protection in Poland and for the Polish motor-vehicle branch, as well as taking into consideration the necessity of adaptation of the Polish rules and regulations to the requirements of the European Union, the said works were intensified by creating, as per the decision of the ITS Director, a Scientific Group for OBD (On-Board Diagnostics) in the mid-1999, which comprises of interdisciplinary group of the ITS employees and well-known specialists in the fields of diesel engines and electronics working at technical schools.