PM TRAPPER FAILURE DETECTING SYSTEM

摘要

It is possible to provide a technique for enabling an accurate detection of a PM trapper failure. The technique uses a differential pressure sensor (20) for detecting a pressure difference between the front and the rear of a PM trapper (11). A failure of the PM trapper is detected according to a change amount of the pressure difference between the front and the rear of the PM trapper (11) in two different operation states of an internal combustion engine (1) where the ambient temperature of the differential pressure sensor (20) is within a predetermined range. Since it is possible to suppress the offset error fluctuations of the differential pressure sensor (20) caused by a change of the ambient temperature of the differential pressure sensor (20), it is possible to detect a change amount of the pressure difference between the front and the rear of the PM trapper (11) with a higher accuracy and detect a failure of the PM trapper (11) more accurately.