Patent ID: 7204239
Filing Date: 2007-04-17
Classification: F02M

Abstract:
1. A failure diagnostic apparatus for an in-tank canister system, comprising: a canister which is provided in a fuel tank; an evaporation passage through which evaporated fuel generated in the fuel tank is introduced into the canister; an atmospheric air passage which permits communication between an inside of the canister and atmospheric air; a purge passage through which the evaporated fuel in the canister is introduced into an intake system of an internal combustion engine; a blocking device which can block a passage that permits communication between the inside of the canister and an outside of the canister; a negative pressure generating device which applies a negative pressure to the inside of the canister; a fuel tank pressure detecting device which detects a pressure in the fuel tank; a canister pressure detecting device which detects a pressure in the canister; and a controller which is configured to change an operation state of each of the blocking device and the negative pressure generating device to a predetermined operation state, and detect at least one of the pressure in the fuel tank and the pressure in the canister by using the fuel tank pressure detecting device and the canister pressure detecting device, thereby determining whether a failure has occurred in the at least one of the fuel tank and the canister whose pressure has been detected.