| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a device for detecting a failure in a valve stop mechanism that allows determination of the number of valves in abnormal operation with respect to a valve stop request in an internal combustion engine having a valve stop mechanism. <P>SOLUTION: An A/F value in exhaust gas is detected (step S1) so as to determine whether or not it is under a valve stop request (step S2). When it is under the valve stop request, the elapsed time tx from the valve stop request is calculated (step S3). Then, it is determined whether or not the detected A/F value in exhaust gas is in a lean state where the exhaust gas contains air (oxygen) more than the stoichiometric value by a certain level (a step S4). When not being in the lean state, it is determined that there is no exhaust-valve failure (step S6). On the other hand, when being in the lean state, the state of changes in A/F is compared with a pre-stored map so as to specify the failed exhaust valve (step S5). <P>COPYRIGHT: (C)2012,JPO&INPIT |
