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.

Date of Patent:
Feb. 10, 1998

Filed:

Sep. 07, 1994
Applicant:
Inventors:

Takuya Matsumoto, Kyoto, JP;

Toru Hashimoto, Kyoto, JP;

Mitsuhiro Miyake, Kyoto, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ; F02D / ; F02D / ;
U.S. Cl.
CPC ...
731181 ; 73116 ; 12333915 ; 36443103 ; 36443107 ;
Abstract

A system for the diagnosis of an idling speed control system has a first timer for measuring the time elapsed since entrance to a feedback control mode, an engine speed state detection unit for detecting whether the engine speed has fallen within a predetermined speed range, a second timer for measuring the time elapsed since the engine speed has been detected to fall within the speed range, and a normality determining unit for determining that the idling speed control system is in order, when the time measured by the first timer is within a first preset time and also the engine speed is detected to have fallen within the speed range and has remained in the speed range until the time measured by said second timer reaches a second preset time. By adopting such a diagnosis method that instead of instantaneously determining an idling speed control system as being in order even after the engine speed has once fallen within a speed range to which the engine is intended to be controlled, any subsequent potential disorder of the idling speed control system is also taken into consideration. This has made it possible to obtain high-reliability information, for example, even when information for the diagnosis of a fault of the idling speed is collected on board.


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