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:
Jul. 05, 1994
Filed:
Apr. 02, 1993
Tokiji Itoh, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
An engine controller executes the feedback control of an amount of the fuel injected, such that an air-fuel ratio (A/F) of the exhaust gas approaches a theoretical ratio. The amount of the fuel injected is as a function of a changeable feedback correction factor (FAF). When the engine is in a predetermined condition in which the engine controller interrupts the feedback control, a secondary air supplier supplies secondary air from an intake passage to an exhaust passage, and changes the A/F ratio of the exhaust gas. Furthermore, when the engine controller executes the feedback control operation, the secondary air is temporarily supplied to the exhaust passage, for the purpose of diagnosis of the supplier. The diagnostic system detects a first feedback correction factor before the secondary air is supplied, and a second feedback correction factor after the secondary air has been supplied, and calculates a deviation value therebetween. The system determines that the secondary air supplier is malfunctioning, when the deviation value (.DELTA.FAF) is smaller than a predetermined value (.alpha.).