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. 14, 2008
Filed:
Jun. 08, 2006
Kenji Tashiro, Toyota, JP;
Yasushi Iwazaki, Ebina, JP;
Masanobu Kanamaru, Mishima, JP;
Hiroshi Sawada, Gotenba, JP;
Masaya Kawaji, Susono, JP;
Takashi Matsui, Koube, JP;
Kenji Tashiro, Toyota, JP;
Yasushi Iwazaki, Ebina, JP;
Masanobu Kanamaru, Mishima, JP;
Hiroshi Sawada, Gotenba, JP;
Masaya Kawaji, Susono, JP;
Takashi Matsui, Koube, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
An air-fuel ratio sensor that outputs a sensor signal used for the feedback control of an air-fuel ratio is provided. It is determined whether an element crack is present by applying a reverse voltage to the air-fuel ratio sensor. The value of the sensor signal output from the air-fuel ratio sensor is corrected during a time period 'A'. The time period 'A' consists of a reverse-voltage application time period in which the reverse voltage is applied, and a return time period “T” after application of the reverse voltage ends. The return time period “T” is set based on sensor impedance correlated with the internal resistance of the air-fuel ratio sensor. The return time period “T” decreases as the sensor impedance decreases.