Title:
LEAK DIAGNOSTIC DEVICE FOR FUEL EVAPORATIVE GAS PURGE SYSTEM
Document Type and Number:
Japanese Patent JP3937263
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To surely prevent erroneous diagnosis that there is leak in a fuel evaporative gas purge system by the opening of the filler cap of a fuel tank.
SOLUTION: In the case of diagnosis that there is leak in a purge system, if an idle operation condition is set up, a canister closing valve is fully closed, and a purge control valve is opened, then intake pipe negative pressure is introduced to the inside of the purge system under atmospheric pressure (steps 141-143). After this, it is judged whether or not fuel tank inner pressure PT is set to set pressure (for example, -5 mmHg) or below within reference time (steps 144, 145), and when the PT is set to the set pressure or below within the reference time, it is judged that a filler cap is not opened, therefore diagnosis that there is leak is fixed and a warning lamp is lighted (steps 146, 147). If the PT is not set to the set pressure or below within the reference time from the start of introducing negative pressure, it is judged that the filler cap is opening (step 148), therefore diagnosis that there is leak is canceled (step 149).
Inventors:
Yoshihiro Majima
Miwa Makoto
Miwa Makoto
Application Number:
JP13623598A
Publication Date:
June 27, 2007
Filing Date:
May 19, 1998
Export Citation:
Assignee:
株式会社デンソー
International Classes:
F02M25/08; G01M3/26; G01M15/00; G01M15/04; (IPC1-7): F02M25/08; F02M25/08; G01M3/26; G01M15/00
Domestic Patent References:
| JP10103169A |
Attorney, Agent or Firm:
Muneo Kako