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:
Oct. 26, 1999
Filed:
Dec. 08, 1997
Akira Uchikawa, Atsugi, JP;
Unisia Jecs Corporation, Kanagawa-ken, JP;
Abstract
An object is to carry out abnormality diagnosis of a wide range air-fuel ratio sensor to a high accuracy, with a relatively simple construction. Judgment is made as to whether abnormality diagnosis permit conditions have materialized, and if materialized, a detection value of an air-fuel ratio sensor is monitored. It is then judged if the responsiveness of a change in the detection value of the air-fuel ratio sensor subsequent to changing a target air-fuel ratio is within a predetermined range. If so, an OK judgment is given. If not, an NG judgment is given and a warning lamp is illuminated to advise the driver of the abnormality in the air-fuel ratio sensor so as to take action. With this arrangement, abnormality diagnosis of a wide range air-fuel ratio sensor can be carried out to a high accuracy with a relatively simple construction.