Emission standards are becoming more stringent and at the same time the standards for the On-Board Diagnostic System (OBD) are also continuously enhancing to ensure a more efficient and robust engine emissions monitoring system during the whole vehicle useful life and to improve the quality of the information delivered to the user. In the case of heavy duty diesel vehicles, the Brazilian standards are developed according to the existing European standards (Euro), for example the current standard in Brazil (so called Proconve P7) follows the same requirements of the Euro V with some minor differences.
As a consequence, the applied technologies for exhaust gas after-treatment and sensing systems to meet the requirements are already used in European applications such as Selective Catalytic Reduction System (SCR), Exhaust Gas Recirculation (EGR), Diesel Particulate Filter (DPF) and Diesel Oxidation Catalyst (DOC), as well as temperature, NOx and differential pressure sensors.
Considering that a possible future standard Proconve P8 will be based on the current European Euro VI, this paper is a case study of the OBD System, to compare its features in an engine certified as Euro VI and in an engine certified as Proconve P7 (Euro V), in order to identify the new challenges for a future Brazilian standard. The comparison of the requirements was performed and the behavior of the involved technologies were analyzed in real applications according to the homologation processes specified in each standard.