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. 14, 1998
Filed:
Dec. 03, 1996
Atsushi Iochi, Machida, JP;
Kenichi Goto, Zama, JP;
Nissan Motor Co.Ltd., Yokohama, JP;
Abstract
A leak diagnosis system for an evaporative emission control system executes a correction process of diagnosis decision value. When the purge control of the evaporative emission control system is not executed, a purging line of the system is set in the atmospheric condition for a predetermined time. A pressure sensor installed in the purging line detects a pressure value V.sub.A0 in the atmospheric condition. A control unit of the leak diagnosis system determines a leak decision value V.sub.P0 on the basis of the atmospheric pressure detection value and an equation V.sub.P0 =V.sub.A0 +.DELTA.V.sub.0 where .DELTA.V.sub.0 is a difference between the output value in the predetermined positive pressure P.sub.0 and the output value V.sub.A0 in the atmospheric pressure condition and is constant. Therefore, it becomes possible to accurately execute the leak diagnosis.