Device for detecting malfunction of fuel evaporative purge system
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsKouji Uranishi, Kouichi Osawa
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Abstract
A device for detecting a malfunction of a fuel evaporative purge system comprises a pressure sensor for detecting gas pressure in a purge passage connecting a canister to an intake pipe, and an intake vacuum sensor for detecting a negative pressure in the intake pipe. In the purging condition, the device determines whether the obtained relationship between the detected negative pressure in the purge passage and the detected intake vacuum is within a predetermined area and judges that a malfunction has occurred in the system when the relationship is not within the predetermined area.
Claims13
A device for detecting a malfunction of a fuel evaporative purge system provided with a canister for absorbing fuel vapor evaporated from stored fuel, a purge passage connecting said canister to an intake pipe of an engine, a valve arranged in said purge passage, and means for opening said valve when said engine is operating under a predetermined driving condition, to thereby supply fuel vapor held in said canister to the intake pipe, said device comprising:
- means for detecting a flow of fuel vapor in said purge passage at the predetermined driving condition;
- means for comparing the detected flow of fuel vapor with a predetermined flow of said fuel vapor when said system is operating normally;
- and
- means for determining whether a malfunction has occurred in said system, said determining means cooperating with said comparing means to detect a malfunction of said system.
Dependencies are inferred from the claim text.