Patent ID: 6371089
Filing Date: 2002-04-16
Classification: B60K,B60W,F02M,Y02T,Y10S

Abstract:
An abnormality diagnostic apparatus of a fuel vapor purge system, comprising:a fuel tank connectable in communication to an atmosphere; a main passage connecting the fuel tank and an intake passage of an internal combustion engine via a canister for adsorbing a fuel vapor from the fuel tank; a bypass passage connecting the fuel tank and the intake passage, bypassing the canister; changing means for selectively changing between the main passage and the bypass passage; pressure detecting means for detecting a pressure in the fuel tank; and abnormality determining means for determining whether there is an abnormality in at least one of the bypass passage and the changing means based on the pressure detected by the pressure detecting means before and after an operation of changing between the main passage and the bypass passage is performed while air is flowing from the fuel tank toward the intake passage.