Diagnostic apparatus and diagnostic method for particulate filter

摘要

A diagnostic apparatus for a filter (6) includes: a differential pressure sensor (13) that detects a differential pressure across the filter; an execution portion (10) that executes a forced recovery process that oxidizes and thereby removes particulate matter accumulated in the filter by forcibly increasing a temperature of the filter; and a first diagnostic portion (10) that determines that the filter is in a normal condition if there is a period where a value detected by the differential pressure sensor is on the increase, within a period where the forced recovery process is unexecuted.