The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 1999
Filed:
Jul. 08, 1998
Denso Corporation, Kariya, JP;
Abstract
In an engine fuel supply system, the difference between the actual and target air-fuel ratios, an air-fuel ratio feedback correction coefficient and a learned correction amount are added as a parameter for diagnosing the fuel supply system. The diagnostic parameter is smoothed and the smoothed value is compared with a diagnosis reference value, thereby detecting a malfunction in the fuel supply system. Even if the learned correction amount is not updated, the malfunction in the fuel supply system can be promptly detected from the difference between the actual and target air-fuel ratios and the air-fuel ratio correction coefficient. The diagnosis reference value is determined variably in accordance with engine operating parameters such as the amount of intake air.