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:
Jun. 09, 1998
Filed:
Sep. 04, 1996
Bryce Andrew Schwager, Ypsilanti, MI (US);
Patrick Joseph Curran, Farmington Hills, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
Abstract
An onboard diagnostic mechanism for a sealed vehicle fuel delivery system. By controlling fuel system valves, the electronic engine controller (EEC) periodically subjects the sealed system to an initial vacuum level, then monitors the pressure increase due to evaporative effects during a predetermined test interval. Excessive deviations in measured pressure compared to predetermined criteria produce indications of potential undesired operational conditions. To prevent fuel sloshing which results from aggressive driving or rough roads from producing false output indications, the instantaneous system pressure is compared with a rolling average of tank pressure to produce a difference signal indicative of fuel sloshing. If the resulting difference signal exceeds a predetermined threshold, the monitoring process is aborted in favor of a later test after the fuel sloshing condition terminates.