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U.S. Department of Energy
Office of Scientific and Technical Information

Diagnosing system for an exhaust gas recirculation system of an automotive engine

Patent ·
OSTI ID:5422353
This patent describes a diagnosing system for an exhaust gas recirculation system having an EGR passage communicating an exhaust pipe of an engine with an intake passage of the engine, an EGR valve provided in the EGR passage, control means for opening the EGR valve in accordance with enigne operating conditions comprising: first means for detecting flow rate of recirculated gas in the EGR passage and for producing an actual EGR rate signal dependent on the flow rate; second means for producing a desired EGR rate signal including an allowable range in accordance with engine operating conditions; and third means responsive to the actual EGR rate signal and the desired EGR rate signal for producing a trouble signal as an alarm signal when the actual EGR rate signal is out of the allowable range.
Assignee:
Fuji Jukogyo Kabushiki Kaisha, Tokyo
Patent Number(s):
US 4723528
OSTI ID:
5422353
Country of Publication:
United States
Language:
English