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US 10,774,756 B1Granted
System and method for diagnosing a positive crankcase ventilation valve
AssigneeFord Global Technologies, LLC
InventorsAed M. Dudar, Robert Roy Jentz
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for detecting degradation of a positive crankcase ventilation (PCV) system valve and a cylinder valve. In one example, a method may include comparing a rate of pressure bleed-up in a PCV system during each of a cold-engine condition and a hot-engine condition to differentiate between the PCV valve and the cylinder valve.
Claims20
A method for an engine, comprising:
- differentiating between degradation of a positive crankcase ventilation system (PCV) valve and a cylinder valve based on a rate of pressure bleed-up in a PCV system during each of a cold-engine condition and a hot-engine condition.
A method, comprising:
- at both a first engine temperature and a second engine temperature, spinning an engine unfueled to establish a threshold negative pressure in a positive crankcase ventilation system and then discontinuing spinning the engine and monitoring a pressure bleed-up in the PCV system;
- and
- comparing the pressure bleed-up obtained at the first engine temperature and at the second engine temperature to indicate a degradation of a positive crankcase ventilation system (PCV) valve and a cylinder valve.
A system, comprising:
- a controller storing instructions in non-transitory memory that, when executed, cause the controller to:
- responsive to a predetermined time duration elapsing since a key-off event, spin an engine un-fueled to generate a negative pressure in an intake manifold, transfer the generated negative pressure to a positive crankcase ventilation system (PCV) via a PCV valve housed in a conduit coupling the intake manifold to the PCV system, seal the PCV system, and monitor a first rate of pressure increase in the PCV system via a PCV system pressure sensor;
- responsive to the first rate of pressure increase being higher than a threshold rate, immediately after a subsequent engine shut-down, spin the engine un-fueled to generate the negative pressure in the intake manifold, transfer the generated negative pressure to PCV system via the PCV valve, seal the PCV system, and monitor a second rate of pressure increase in the PCV system via the PCV system pressure sensor;
- and
- in response to the second rate of pressure increase being higher than the threshold rate, indicate degradation of the PCV valve.
2 more elements
Dependencies are inferred from the claim text.