| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a fault diagnosis device that determines a clogged exhaust reflux mechanism in an EGR system including a plurality of exhaust reflux mechanisms. <P>SOLUTION: An engine 1 includes an MPL-EGR system having an HPL-EGR mechanism 6 and an LPL-EGR mechanism 7. When an opening degree of a high-pressure EGR valve 62 in the HPL-EGR mechanism 6 is equal to or more than a predetermined value, and a closing degree of an intake throttle valve 33 is equal to or more than a predetermined value, any mechanism in the MPL-EGR system is determined to be clogged. If an opening degree of a low-pressure EGR valve 72 is less than or equal to a predetermined value, clogging in the HPL-EGR mechanism 6 is determined, and if the opening degree of the low-pressure EGR valve 72 exceeds the predetermined value, clogging in the LPL-EGR mechanism 7 is determined. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
