LEAK DIAGNOSIS DEVICE FOR EVAPORATED FUEL PROCESSING SYSTEM

摘要

The problem addressed by the present invention is to provide a leak diagnosis device that is for an evaporated fuel processing system and that can diagnose leaks regardless of the temperature within a fuel tank. The leak diagnosis device is used in an evaporated fuel processing system provided with a canister (41), which is installed within a fuel tank (31) and adsorbs evaporated fuel arising within the fuel tank (31), and a purge tubing (43), which leads purge gas containing evaporated fuel from the canister (41) into the air intake tube (23) of an engine (2). The leak diagnosis system lights a warning light (51) indicating an abnormality with the condition that the amount of decrease in HC concentration within the purge tubing (43) during a predetermined time period is less than a predetermined threshold.