초록 ▼

To perform leak diagnosis, when it is determined (during engine idling) that leakage exists in the purge system air is reintroduced into a purge system. Then, determination of leakage existence is stopped. Accordingly, erroneous diagnosis caused by opening the filler cap during engine idling is prev

To perform leak diagnosis, when it is determined (during engine idling) that leakage exists in the purge system air is reintroduced into a purge system. Then, determination of leakage existence is stopped. Accordingly, erroneous diagnosis caused by opening the filler cap during engine idling is prevented, and reliability of leakage diagnosis is improved.

대표청구항 ▼

[What is claimed is:] [1.]leakage diagnosing means for diagnosing existence of leakage in the purge system by detecting at least one of: (a) pressure in a part of the purge system at least including the fuel tank and the canister if said part of the purge system is hermetically sealed with said cap

[What is claimed is:] [1.]leakage diagnosing means for diagnosing existence of leakage in the purge system by detecting at least one of: (a) pressure in a part of the purge system at least including the fuel tank and the canister if said part of the purge system is hermetically sealed with said cap after introducing air therein, and (b) pressure change in said part of the purge system if it is hermetically sealed with said cap after introducing air therein;means for reintroducing air into said part of the purge system when it is tentatively determined that leakage exists during idling of the engine; andmeans for canceling said earlier tentative determination of leakage existence if it is determined that said cap likely was not sealed with the tank during the earlier diagnosis.