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:
Apr. 11, 1989
Filed:
Apr. 12, 1988
Kenichi Harada, Susono, JP;
Nobuki Uchitani, Tokushima, JP;
Tatuyoshi Kamohara, Toyota, JP;
Koichi Satoya, Susono, JP;
Takashi Kato, Mishima, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
A diagnostic system of an air-fuel ratio control device including an O.sub.2 sensor and an air bleed control valve actuated in response to a signal output by the O.sub.2 sensor. When the electric control current fed into the air bleed control valve reaches an upper limit or lower limit and remains at the upper limit or lower limit for a fixed time, the diagnostic system determines that the air-fuel ratio control device has malfunctioned. When the temperature of the engine cooling water is high, a diagnosis is prohibited, to prevent an incorrect diagnosis.