摘要 |
A failure diagnosis apparatus for diagnosing a failure of an evaporative fuel processing system wherein a pressure in the evaporative fuel processing system is detected, and a purge control valve and a vent shut valve are closed when stoppage of the engine is detected. A determination is made as to whether there is a leak in the evaporative fuel processing system based on the detected pressure during a predetermined determination period after closing of the purge control and vent shut valves. The determination result is decided according to a parameter indicative of an amount of evaporative fuel generated in the fuel tank after stoppage of the engine. |