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US 10,590,879 B2Granted
Variable displacement engine diagnostic method
AssigneeFord Global Technologies, LLC
InventorAed Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing a variable displacement engine. In one example, a method includes during steady-state vehicle cruising, operating an engine with one or more cylinders of the engine deactivated, commanding the one or more cylinders to reactivate, and indicating cylinder valve actuator degradation responsive to a fuel usage change following the command to reactivate.
Claims18
A method comprising:
- during steady-state vehicle cruising with vehicle speed at least at a threshold speed,
- operating an engine with one or more cylinders of the engine deactivated;
- commanding the one or more cylinders to reactivate;
- and
- indicating cylinder valve actuator degradation responsive to a fuel usage change following the command to reactivate, wherein the fuel usage change is a change in a level of average fuel economy determined from measured fuel consumption relative to a measured distance traveled.
2 more elements
A system for a vehicle including an engine with a deactivatable cylinder and a non-deactivatable cylinder, comprising:
- an intake valve and an exhaust valve each coupled to the deactivatable cylinder, the intake valve and the exhaust valve each selectively actuatable via a variable displacement engine (VDE) actuation system;
- and
- a controller storing instructions in non-transitory memory executable to command the VDE actuation system to switch from a VDE mode where the intake valve and the exhaust valve are not actuated to a non-VDE mode where the intake valve and the exhaust valve are actuated, and indicate degradation of the VDE actuation system responsive to a change in average fuel economy following the command being less than a threshold change, wherein the instructions are executable to indicate that the degradation of VDE actuation system includes the VDE actuation system being stuck in the VDE mode based on the average fuel economy following the command being substantially equal to a baseline fuel economy.
An engine method, comprising:
- during steady-state vehicle cruising,
- determining fuel economy of an engine with one or more deactivated cylinders, the one or more deactivated cylinders including deactivated cylinder valves;
- reactivating the one or more cylinders by activating the deactivated cylinder valves;
- and
- indicating valve actuator degradation responsive to a less than threshold decrease in fuel economy from the determined fuel economy following the reactivating.
2 more elements
Dependencies are inferred from the claim text.