Patent ID: 7082815

Claim:
An evaporated fuel treatment device for internal combustion engine that uses a canister to absorb evaporated fuel generated in a fuel tank for evaporated fuel treatment purposes, said device comprising: a sealing valve for controlling the continuity between said fuel tank and said canister; a close failure judgment means for judging whether a close failure exists in said sealing valve; a pressure introduction means for introducing pressure into either said canister or said fuel tank in a situation where said sealing valve is closed; a sealing valve open instruction generation means for issuing a valve open instruction to said sealing valve in a situation where pressure is introduced into either said canister or said fuel tank by said pressure introduction means; a pressure change judgment means for conducting a check, before and after the issuance of said valve open instruction, to judge whether a significant pressure change occurs in said canister or said fuel tank to which pressure is not introduced; and an open failure abnormality judgment means for making a judgment that an open failure exists in said sealing valve when said significant pressure change is not verified by said pressure change judgment means under a circumstance where no close failure record exists.