| 摘要 |
A method of leak detection for an evaporative emission control system is provided which determines if a potential leak is present in a portion of the system. The method includes the steps of monitoring an engine shut-off event and subsequently sealing the evaporative emission control system atmospheric vent such that the evaporative emission control system's internal pressure is isolated from external influences, absent a leak. After sealing the system, the internal pressure of the system is monitored for changes which should occur upon the cooling of the evaporative emission control system components. That is, when the components cool, the pressure within the sealed system should decrease. If the internal pressure of the evaporative emissions control system reduces so as to create a vacuum, the methodology assesses that no leaks in the system are present. However, if the internal pressure within the evaporative emission control system does not create a vacuum upon cooling of the components, the methodology assesses that a potential leak exists in the system.
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