Other

Satoru Osaki

Toshio Hori

Takeshi Tsuyuki

Osamu Matsuno

A failure diagnosis apparatus for an exhaust gas recirculation system eliminates the influence of various disturbance factors that vary the suction air pressure, diagnoses a failure of the exhaust gas recirculation system on the basis of the suction air pressure, and prevents incorrect diagnosis. The system includes a fresh air pressure unit for determining an estimated fresh air pressure inside a suction pipe from the operating condition of an internal combustion engine and an actual exhaust gas recirculation pressure estimating unit for determining an EGR gas pressure on the basis of a measured suction pipe pressure detected by a suction pipe pressure detecting unit and estimated fresh air pressure. A failure is judged on the basis of the estimated EGR gas pressure and the detected operating condition.

Failure diagnosis apparatus for exhaust gas recirculation system

To provide a failure diagnosis apparatus for an exhaust gas recirculation system which is capable of eliminating the influence of various disturbance factors that vary the suction air pressure, diagnosing a failure of the exhaust gas recirculation system on the basis of the suction air pressure, and preventing wrong diagnosis. A failure diagnosis apparatus for an exhaust gas recirculation system consists of a fresh air pressure estimating means for calculating an estimated fresh air pressure inside a suction pipe from the operating condition of an internal combustion engine, an actual EGR (exhaust gas recirculation) gas pressure estimating means for estimating an EGR gas pressure on the basis of a measured suction pipe pressure detected by a suction pipe pressure detecting means and an estimated fresh air pressure calculated above, and a failure judging means for judging the failure on the basis of the estimated EGR gas pressure and the detected operating condition.

To provide a failure diagnosis apparatus for an exhaust gas recirculation system which is capable of eliminating the influence of various disturbance factors that vary the suction air pressure, diagnosing a failure of the exhaust gas recirculation system on the basis of the suction air pressure, and preventing wrong diagnosis. A failure diagnosis apparatus for an exhaust gas recirculation system consists of a fresh air pressure estimating device for calculating an estimated fresh air pressure inside a suction pipe from the operating condition of an internal combustion engine, an actual EGR (exhaust gas recirculation) gas pressure estimating device for estimating an EGR gas pressure on the basis of a measured suction pipe pressure detected by a suction pipe pressure detecting device and an estimated fresh air pressure calculated above, and a failure judging device for judging the failure on the basis of the estimated EGR gas pressure and the detected operating condition.

Growing community of inventors

Hitachinaka, Japan

Satoru Osaki