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:
Apr. 16, 1996
Filed:
Jun. 24, 1994
David R Wade, Waterford, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
Restrictions in a path of flow of recirculated internal combustion engine exhaust gas from an engine exhaust system to an engine intake manifold are diagnosed when the engine is determined to be in a steady state operating condition through a monitoring of the air pressure in the engine intake manifold while the flow of exhaust gas thereto is varied according to a predetermined flow schedule. Changes in the monitored air pressure are determined over a test period, are filtered through a lag filter process having a dynamic filter coefficient, and are compared to a dynamic threshold to determine a presence of a restriction. The filter coefficient and the threshold may be adjusted in accord with the outcome of the diagnostic.