| 摘要 |
A method of diagnosing the fuel flow of a fuel system for a vehicle is provided to detect the fuel accumulation in the early stage between a fuel tank and a canister using a concentration of evaporated gas, a purge duty cycle, a pressure of tank. A method of diagnosing the fuel flow of a fuel system for a vehicle comprises the step of determining whether a fuel system satisfies a fuel flow diagnosis start condition. If the fuel flow diagnosis start condition is satisfied, a normalcy of an evaporated gas controlling device is determined. If the evaporated gas controlling device is normal, it is determined whether the evaporated gas controlling device satisfies a malfunction judgment condition. If the malfunction judgment condition is satisfied, it is determined whether a concentration of a canister exceeds a reference value. If the concentration of the canister exceeds the reference value, it is determined whether a learning value of a fuel injection exceeds a rich judgment reference value. If a learning value of a fuel injection exceeds a rich judgment reference value, a malfunction judgment counter is increased, and it is determined whether the malfunction judgment counter exceeds a malfunction judgment reference value. If the malfunction judgment counter exceeds the malfunction judgment reference value, it is determined that fuel is collected between a fuel tank and the canister. |
