Method and system for diagnosing boost pressure control
AssigneeFord Global Technologies, LLC
InventorsStephen William Magner, Michiel J. Van Nieuwstadt, John Erik Mikael Hellstrom, In Kwang Yoo, Adarsh Appukuttan, Jason Ronald Smith
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Abstract
Methods and systems are provided for providing passive boost pressure monitoring for slow response with higher confidence. A response time of a boost pressure feedback control loop following a boost pressure deviation that is triggered by either system disturbances or operator torque demand is monitored. Slow boost behavior is correlated with boost control degradation affecting drivability and emissions.
Claims18
A diagnostic method for a boosted engine in a vehicle, comprising:
- entering a diagnostic monitor and adjusting an actuator while operating an engine with closed-loop turbocharger boost control via a controller, and providing an indication of degradation via the controller based on a duration of an actual deviation being higher than a threshold deviation between an expected change in boost pressure and an actual change in boost pressure over a drive cycle, without referencing a variable geometry turbine (VGT) or waste-gate command or measurement,
- wherein the engine is operated with closed-loop turbocharger boost control at non-idling conditions via the controller including each of a threshold vehicle run time having elapsed, a threshold engine temperature being reached, and a threshold intake manifold pressure being maintained.
A diagnostic method for a boosted engine in a vehicle, comprising:
- via a controller, entering a diagnostic monitor, adjusting an actuator, and monitoring a response time to selected boost pressure deviations triggered by an operator, independent of referencing a commanded or measured waste-gate position;
- and
- responsive to the monitored response time being longer than a threshold duration while qualifying vehicle operating conditions are met, generating an indication of degradation via the controller,
- wherein generating the indication of degradation responsive to the monitored response time includes indicating degradation independent of a magnitude of the selected boost pressure deviations once the threshold duration is elapsed, and independent of referencing the commanded or measured waste-gate position.
A vehicle system, comprising:
- an engine;
- a turbocharger including an intake compressor driven by an exhaust turbine;
- a waste-gate valve positioned in a waste-gate coupled across the exhaust turbine;
- a timer;
- and
- a controller with computer-readable instructions stored on non-transitory memory for:
- responsive to a change in demanded boost pressure and feedback detected disturbances, adjusting a position of the waste-gate valve and initiating the timer;
- monitoring a duration elapsed on the timer to complete a pressure deviation correction corresponding to a demanded difference between an expected boost pressure and an actual boost pressure following the adjusting;
- and
- indicating degraded boost response time to a vehicle driver based on the monitored duration.
Dependencies are inferred from the claim text.