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. 30, 2019
Filed:
Oct. 01, 2013
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Hiroshi Miyamoto, Shizuoka, JP;
Yasushi Iwazaki, Ebina, JP;
Keiichiro Aoki, Shizuoka, JP;
Toru Kidokoro, Hadano, JP;
TOYOTA JIDOSHA KABUSHIKI KAISHA, Aichi, JP;
Abstract
The abnormality diagnosis system of an air-fuel ratio sensor comprising an exhaust purification catalyst, an upstream side air-fuel ratio sensor provided at an upstream side of the exhaust purification catalyst, a downstream air-fuel ratio sensor provided at a downstream side of the exhaust purification catalyst, and a diagnosis device diagnosing the downstream air-fuel ratio sensor for abnormality based on outputs of these air-fuel ratio sensors. The diagnosis device judges that the downstream air-fuel ratio sensor suffers from an abnormality if the output air-fuel ratio of the upstream side air-fuel ratio sensor has become a rich air-fuel ratio richer than a stoichiometric air-fuel ratio, and the output air-fuel ratio of the downstream air-fuel ratio sensor air-fuel ratio has changed from an air-fuel ratio richer than a lean judged reference air-fuel ratio to an air-fuel ratio leaner than the lead judged reference air-fuel ratio. As a result, it is possible to accurately diagnose an abnormality of a downstream air-fuel ratio sensor when using an air-fuel ratio sensor as a downstream side sensor.