METHOD AND SYSTEM FOR DIAGNOSING AN AFTERTREATMENT SYSTEM

The present invention relates to a method for diagnosing aftertreatment of exhaust gases resulting from combustion, wherein at least a first substance (NOx) resulting from said combustion is reduced by supplying additive to an exhaust gas stream resulting from said combustion and use of a first reduction catalytic converter (201). The method includes: - estimating an accumulated expected reductionof said first substance (NOx) during a first period of time (tlim1), - determining an accumulated actual reduction of said first substance (NOx) during a period of time at least substantially overlapping said first period of time (tlim1), and - generating a signal indicating a fault in said reduction of said first substance (NOx) when said accumulated actual reduction differs from said accumulated expected reduction by a predetermined difference in occurrence of said first substance (NOx). The invention also relates to a corresponding system. 本发明涉及种诊断燃烧产生的排气的后处理的方法，其中由所述燃烧产生的第物质(NO)至少通过对所述燃烧产生的排气流供应添加剂并且使用第还原催化转化器(20