摘要 |
<p>The present invention is intended to provide a technique which is capable of improving detection accuracy at the time of performing failure detection of a particulate filter by the use of a PM sensor. In the present invention, the PM sensor is arranged in an exhaust passage at the downstream side of the particulate filter. Then, the presence or absence of a failure in the particulate filter is determined by making a comparison between an output value of the PM sensor at the time when a predetermined period of time has elapsed after the execution of PM removal processing to remove the particulate matter deposited on the PM sensor is completed, and a predetermined threshold value. At this time, the threshold value is set based on an average value of an amount of intake air in an internal combustion engine during the passage of the predetermined period of time.</p> |