Pilot downshifting system and method
AssigneeFord Global Technologies, LLC
InventorsKristofor Robert Norman, Shuya Shark Yamada
Life of this patent
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Abstract
Methods and systems are provided for performing a multiple gear downshift of a transmission gear by transiently operating in an intermediate gear. In response to air mass flow not reaching a threshold for CAC self-cleansing for a set duration, the transmission gear may be downshifted from a higher gear to an intermediate gear, and then to a requested lower gear. Downshifting through an intermediate gear may also be controlled based on the gear shift request and maximum air mass flow levels for engine misfire.
Claims21
A method for an engine, comprising:
- in response to airflow through a charge air cooler and a request to downshift a transmission gear from a higher gear to a lower gear, transiently operating at an intermediate gear before shifting to the lower gear.
A method for an engine, comprising:
- in response to a multiple gear downshift request, when air mass flow is less than a threshold range for a threshold duration and the multiple gear downshift request will increase air mass flow over a second threshold level, downshifting a transmission from a higher gear to an intermediate gear, and then to a requested lower gear.
A method for an engine, comprising:
- during a first condition, when an air mass flow is less than a threshold range for a threshold duration, shifting from a higher gear to a requested lower gear by transiently operating at an intermediate gear before shifting to the lower gear;
- and
- during a second condition, when an air mass flow is not less than a threshold range for a threshold duration, shifting from the higher gear to a lower gear when requested, without operating in the intermediate gear.
Dependencies are inferred from the claim text.