Method and system for diagnosing an evaporative emissions system
AssigneeFord Global Technologies, LLC
InventorAed Dudar
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Abstract
Methods and systems for diagnosing operation of an evaporative emissions system are described. The methods and systems may include increasing an amount of vacuum stored in an evaporative emissions system during discontinuously operating an engine in a boosted operating mode. Storing vacuum allows the evaporative emissions system to reach a desired vacuum level to verify absence of an evaporative emissions system breech.
Claims16
A method for operating an evaporative emissions system of a vehicle in response to an evaporative emissions diagnostic request, comprising:
- generating vacuum via an ejector when an engine is operating under boost during a first period;
- trapping the generated vacuum when the engine does not operate under boost during a second period subsequent to the first period;
- increasing the generated vacuum when the engine operates under boost during a third period subsequent to the second period;
- and
- determining a result of the diagnostic subsequent to the third period,
- where the generated vacuum is a first amount in the first period and the generated vacuum is increased to a second amount during the third period, and the second amount is greater than the first amount.
A method for operating an evaporative emissions system of a vehicle in response to an evaporative emissions diagnostic request, comprising:
- increasing an amount of vacuum in the evaporative emissions system during a first boosted operation,
- closing a valve to maintain evaporative emissions system pressure during a first non-boosted operation subsequent to the first boosted operation, and
- increasing the amount of vacuum in the evaporative emissions system during a second boosted operation subsequent to the first non-boosted operation,
- where the increasing of the amount of vacuum uses an ejector and the first boosted operation increases an amount of vacuum to a first amount and the second boosted operation increases the amount of vacuum from the first amount to a second amount.
Dependencies are inferred from the claim text.