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:
Apr. 23, 2002

Filed:

Jan. 26, 2001
Applicant:
Inventors:

Akihiro Shinjyo, Saitama-ken, JP;

Hiroshi Kitagawa, Saitama-ken, JP;

Toshihiro Mibe, Saitama-ken, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F02D 4/122 ;
U.S. Cl.
CPC ...
F02D 4/122 ;
Abstract

An apparatus for accurately and promptly determining a failure of an oxygen concentration sensor. The oxygen concentration sensor is arranged at a location downstream of a catalyst in an exhaust system of an internal combustion engine. The apparatus measures a time period elapsed after termination of a fuel cut-off operation, and calculates an integrated amount SUMSVS of exhaust gases exhausted after the termination of the fuel cut-off operation. A failure of the oxygen concentration sensor is determined depending on whether or not a signal value SVO2 of a signal from the oxygen concentration sensor has crossed a predetermined threshold value #SVO2CHK. Further, when a predetermined time period #TMFCCKD has elapsed, if the signal value SVO2 has not crossed the predetermined threshold value #SVO2CHK, and at the same time when the integrated amount SUMSVS of the exhaust gases has not reached a predetermined value #SUMSVAFC the failure determination is suspended.


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