SCR Monitoring for USA Tier2 and Europe EUR06 OBD

摘要

To meet severe NO_x emission target for Tier2 Bin5 and EUR06, car makers are considering applying urea SCR systems. Also, its system performance should be monitored through the life time and informed to the customer under the OBD regulations. This paper investigates the feasibility of the threshold monitoring with current NO_x sensor. It is shown that OBD for US and EUR06 threshold monitoring is not possible with current ones. The degree of NO_x sensor accuracy is calculated to monitor the SCR. Also, we suggest the combination of NO_x sensors that threshold monitoring is possible with current NO_x sensors.