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.

Date of Patent:
May. 11, 1993

Filed:

Jul. 10, 1991
Applicant:
Inventors:

Yoshiaki Danno, Kyoto, JP;

Tetsurou Ishida, Kyoto, JP;

Yoshiaki Kodama, Kyoto, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02M / ;
U.S. Cl.
CPC ...
123479 ; 123672 ;
Abstract

An air-fuel ratio control system compares an air-fuel ratio indicated by air-fuel ratio information from an air-fuel ratio sensor and a target air-fuel ratio determined depending on operating conditions of a motor vehicle which incorporates the air-fuel ratio control system, for reliably determining at least a failure of the air-fuel ratio sensor. When a failure of the air-fuel ratio sensor is detected, an air-fuel ratio feedback control process is stopped or the air-fuel ratio sensor is disabled, preventing the air-fuel ratio from being corrected in error based on an output signal from the air-fuel ratio sensor which has failed. Therefore, the air-fuel ratio control system prevents problems such as poor exhaust gas purification, reduced drivability, and unstable engine idling from taking place.


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