Method and apparatus for evaporative emissions control

摘要

A method of controlling an evaporative emissions system of a vehicle includes determining that a refueling event has been requested by a vehicle occupant, detecting a pressure inside a fuel tank, and impeding opening of a fuel tank inlet if the pressure is above a limit value. After the refueling event, an open/closed status of a fuel inlet access door is monitored, a fuel level inside a fuel tank is monitored, and a vehicle engine an operating condition is monitored. Pressure buildup within the fuel tank is disabled if a) the open/closed status has not changed from closed to open, and b) the fuel level has increased, and c) the vehicle engine is operating. An operator alert may be generated, and/or a fault code may be set in a vehicle diagnostic system.

主权项

1. A method of diagnosing failure of a fuel inlet access door condition sensor and preventing pressurization of a fuel tank of a vehicle after a refueling event, comprising:
detecting that the sensor has not changed from a door closed to a door open indication; detecting that a fuel level inside the fuel tank has increased by more than a threshold amount; detecting that a vehicle engine has been restarted; and in response to the above conditions, inferring a failure of the sensor and preventing closing an isolation valve that, when closed, isolates the fuel tank from a vapor recovery canister.