| 摘要 |
A method of diagnosing efficiency of an aftertreatment system 270 of an internal combustion engine 110, wherein the aftertreatment system comprises an exhaust duct 275, an oxidation catalyst 280 (e.g. a diesel oxidation catalyst - DOC) disposed in the exhaust duct, and a particulate filter 285 (e.g. a diesel particulate filter - DPF) disposed in the exhaust duct downstream of the oxidation catalyst. The method comprises the steps of: operating the internal combustion engine to perform a regeneration process of the particulate filter; determining a first value of exhaust gas temperature in the exhaust duct between the oxidation catalyst and the particulate filter; determining a second value of exhaust gas temperature in the exhaust duct downstream of the particulate filter; identifying a malfunctioning of the oxidation catalyst if, during the regeneration process, the first value of exhaust gas temperature is below a first predetermined threshold value, and contemporaneously the second value of exhaust gas temperature is above a second predetermined threshold value. |
