| 摘要 |
PROBLEM TO BE SOLVED: To highly maintain the frequency of the times of diagnosis and detection by making compatible the quick diagnosis and detection of a large leak caused when a failure to close a fuel cap occurs with the diagnosis and detection of a very small leak such as a leak through a small gap to secure high accuracy by using a pump with a small discharge. SOLUTION: This evaporated fuel treating device comprises a control means having an abnormality determination part for determining the presence or absence of an abnormality of an evaporated fuel control passage by diagnosing a change of pressure in a fuel tank. The control means closes a selector valve and a purge valve while predetermined requirements of diagnosis including the determination that the supply of oil into the fuel tank is present and that the internal combustion engine is being operated are established, stops a pressure reducing pump, maintains the state of the inside of the fuel tank for a predetermined time without bringing the state into a negative pressure, and compares the change of pressure in the fuel tank with a predetermined amount of change set beforehand by the abnormality determination part for performing a first determination to determine whether an abnormality is present or not. COPYRIGHT: (C)2007,JPO&INPIT
|
