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. 06, 1998
Filed:
Jun. 06, 1996
Applicant:
Inventor:
Yoichi Iwata, Yokohama, JP;
Assignee:
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02D / ; G01M / ;
U.S. Cl.
CPC ...
701103 ; 701107 ; 123672 ; 123688 ;
Abstract
A device is provided for detecting a malfunction of an air fuel ratio sensor disposed downstream of a catalytic converter in an exhaust passage of an engine. The device calculates a differential value of a sensor output with respect to time. Then the device compare the differential value of said sensor output with a predetermined value and calculate a frequency of the differential value of the sensor output which exceeds the predetermined value. Then the device compares the frequency with a predetermined value and determine that the sensor is malfunctioning if the frequency does not exceed the predetermined value.