| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control device of an internal combustion engine capable of accurately determining an abnormality of a NOx catalyst, properly securing an opportunity to execute a lean-burn operation and thereby improving fuel economy of the internal combustion engine. <P>SOLUTION: In this control device, whether or not the NOx catalyst is abnormal is temporarily determined based on capturing capacity of NOx of the NOx catalyst (step 18), and the temporary determination is inhibited when a temperature TLNC of the NOx catalyst is an upper limit temperature TLMTH having a prescribed value as an initial value or more (step 11-13). When it is temporarily determined that the NOx catalyst is abnormal, the upper limit temperature TLMTH is updated to a lower side (step 22), and the lean-burn operation is inhibited during inhibition of the temporary determination. When it is temporarily determined that the NOx catalyst is abnormal and the updated upper limit temperature TLMTH becomes a prescribed determination temperature TJUD lower than the initial value or below, it is determined that the NOx catalyst is abnormal (step 26). <P>COPYRIGHT: (C)2013,JPO&INPIT |
