Patent ID: 8656763

Claim:
A failure detection apparatus for a particulate filter in which a failure of the particulate filter arranged in an exhaust passage of an internal combustion engine is detected, said failure detection apparatus comprising: a PM sensor that is arranged in the exhaust passage at the downstream side of said particulate filter, and outputs a signal corresponding to an amount of particulate matter deposited on itself; a PM removal processing execution part that executes PM removal processing to remove the particulate matter deposited on said PM sensor; a failure determination part that determines the presence or absence of a failure in said particulate filter by making a comparison between an output value of said PM sensor at the time when a predetermined period of time has elapsed after the execution of the PM removal processing by said PM removal processing execution part is completed, and a predetermined threshold value; an average intake air amount calculation part that calculates an average value of an amount of intake air in the internal combustion engine during a time after the execution of the PM removal processing by said PM removal processing execution part is completed until said predetermined period of time elapses; and a threshold setting part that sets said threshold value based on the average value of the amount of intake air calculated by said average intake air amount calculation part.