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:
Jul. 20, 2004
Filed:
Dec. 12, 2002
Katsuhiro Kumagai, Saitama-ken, JP;
Shinichi Kitajima, Saitama-ken, JP;
Futoshi Nishioka, Saitama-ken, JP;
Toshinari Shinohara, Saitama-ken, JP;
Kan Nakaune, Saitama-ken, JP;
Atsushi Matsubara, Saitama-ken, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A failure determination system and method for an internal combustion engine and an engine control unit are provided which are capable of properly determining a failure of a variable valve mechanism for inactivating a valve system associated with at least one of cylinders during a predetermined operation of the engine, by discriminating a misfire caused by the failure of the mechanism from a normal misfire. Fuel injection valves inject fuel for each cylinder and oxygen concentration of exhaust gases is detected. A misfire condition is detected on a cylinder-by-cylinder basis. Fuel injection to a misfiring cylinder is stopped. A failure of the mechanism is determined, when a parameter based on the oxygen concentration detection indicates a richer value of an actual air-fuel ratio of the exhaust gases than a predetermined reference value does, under a condition of the fuel injection being stopped.