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:
Nov. 25, 2003

Filed:

May. 24, 2002
Applicant:
Inventors:

Kenji Saito, Okazaki, JP;

Satoshi Nagashima, Okazaki, JP;

Yoichiro Ando, Seto, JP;

Hidetsugu Kanao, Okazaki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01L 3/26 ; G01L 5/13 ; G01M 1/500 ;
U.S. Cl.
CPC ...
G01L 3/26 ; G01L 5/13 ; G01M 1/500 ;
Abstract

There is provided a failure diagnostic system of an evaporated fuel processing system, which comprises a first failure diagnostic device that shuts off an evaporated fuel purge passage connecting a fuel tank and an engine intake passage from the air and determines whether there is any leakage from a large hole by monitoring the degree of increase in pressure in the fuel tank in which engine intake negative pressure is introduced; and a second failure diagnostic device that reduces a pressure the fuel tank to a predetermined negative pressure and seals off the fuel tank from the air to carry out failure diagnosis as to whether there is any leakage from a small hole by monitoring the degree of increase in pressure in the fuel tank. An operating range of the second failure diagnostic device is set to substantially include an operating range of the first failure diagnostic device and to be extended from the operating range of the first failure diagnostic device to include a lower intake negative pressure range.


Find Patent Forward Citations

Loading…