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:
Mar. 10, 1992
Filed:
Jun. 05, 1991
Joseph M Kotzan, Clarkston, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
The fuel system of an internal combustion engine diagnosed based on a learn term adjusted in response to a closed loop adjustment of the air fuel ratio and which is used along with the closed loop adjustment to determine the fuel amount supplied to the engine. The learn term is adjusted at a first rate based on the integral correction term. If the learn term reaches a predetermined primary rich or lean limit value and the closed loop integral adjustment reaches its authority limit, the learn term is further adjusted at a second rate that is slower than the first rate. When the learn term exceeds a predetermined secondary rich or lean limit value representing an adjustment that is greater than the adjustment represented by the corresponding primary rich or lean limit value, a fuel system fault is indicated.