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.:

US 7243532 B1

PDF
Full Text
Expired
Date of Patent:
Jul. 17, 2007

Filed:

Dec. 02, 2004
Applicants:

Tomohiro Tsujimura, Kariya, JP;

Noriaki Ikemoto, Obu, JP;

Inventors:

Tomohiro Tsujimura, Kariya, JP;

Noriaki Ikemoto, Obu, JP;

Assignee:

DENSO Corporation, Kariya, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01M 15/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

Air fuel ratios of exhaust gases of respective cylinders are estimated based on a detection value of an air fuel ratio sensor mounted in an exhaust-collector. Normal combustion and misfire are determined depending upon whether individual cylinder air fuel ratios of the respective cylinders are within a normal combustion range. Then, whether a fuel system causes misfire is determined based on a difference between an actual injection quantity of the misfire cylinder and an average value of actual injection quantities of all the cylinders. Whether an air system causes misfire is determined based on a difference between an estimated air quantity of the misfire cylinder and an average value of actual air quantities of all the cylinders.


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