Failure diagnostic apparatus and failure diagnostic method for in-tank canister system

摘要

A blocking device provided in an evaporation passage is placed in an open state such that communication between an inside of a canister and an inside of a fuel tank is permitted, a negative pressure generating device provided in an atmospheric passage is operated, and a pressure in the fuel tank is detected, whereby whether a failure has occurred in the fuel tank is determined. Then, the blocking device is placed in a blocking state, the negative pressure generating device operated, and a pressure in the canister is detected, whereby whether a failure has occurred in the canister is determined.