| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To decide abnormality in opening and closing operation of an EGR valve and an intake throttle valve using a pressure sensor in an internal combustion engine. <P>SOLUTION: In the internal combustion engine 1, NOx is reduced by supplying a reducing agent to a particulate filter 12 carrying a storage reduction type NOx catalyst. In this method for determining abnormality in the internal combustion engine, the abnormality in opening and closing operation of the EGR valve 15 or the intake throttle valve 7 is determined by a change in pressure of upstream of the particulate filter 12 at the time of reducing NOx. When the EGR valve 15 or the intake throttle valve 7 is opened or closed, a flow rate of an exhaust gas is changed and the pressure of the upstream of the filter is changed. Since the opening and closing operation of the EGR valve 15 or the intake throttle valve 7 correlates with the pressure of the upstream of the filter 12, it is possible to decide the abnormality in opening and closing operation of the EGR valve 15 or the intake throttle valve 7 based on the pressure of the upstream of the filter 12. <P>COPYRIGHT: (C)2004,JPO</p> |
