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US 10,947,921 B2Granted
Systems and methods for intake oxygen sensor diagnostics
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing whether one or more intake air oxygen sensors positioned in an intake of an engine of a vehicle, are functioning as desired. In one example, a method comprises injecting fuel into one or more cylinders of the engine without combustion, routing un-combusted hydrocarbons from the one or more cylinders to the intake via a crankcase ventilation system, and indicating whether the one or more intake air oxygen sensors are functioning as desired based on a response of the one or more intake air oxygen sensors. In this way, the one or more intake air oxygen sensors may be periodically diagnosed which may improve engine operation, and reduce engine degradation, particularly with regard to hybrid electric vehicles with limited engine run-time.
Claims19
A method comprising:
- injecting fuel into one or more cylinders of an engine of a vehicle without combustion, and routing un-combusted hydrocarbons from the one or more cylinders to a crankcase of the engine, the crankcase included in a crankcase ventilation system, and then to an intake manifold of the engine, in order to diagnose whether a first intake air oxygen sensor positioned in the intake manifold is functioning as opposed to malfunctioning due to degradation;
- and
- subsequent to routing un-combusted hydrocarbons to the intake manifold of the engine, routing the un-combusted hydrocarbons to a position upstream of the intake manifold of the engine, to diagnose whether a second intake air oxygen sensor positioned in an intake passage of the engine is functioning.
A method comprising:
- spinning an engine of a vehicle in a forward direction while providing fuel injection but not spark and operating the engine in a first mode to obtain a first baseline response of a first intake air oxygen sensor positioned in an intake manifold of the engine and to obtain a second baseline response of a second intake air oxygen sensor positioned in an intake passage upstream of the intake manifold;
- subsequent to obtaining the first baseline response and the second baseline response, maintaining spinning the engine in the forward direction with fuel injection but not spark and operating the engine in a second mode to route un-combusted hydrocarbons to the first intake air oxygen sensor and the second intake air oxygen sensor via a crankcase ventilation system;
- and
- indicating whether the first intake air oxygen sensor and the second intake air oxygen sensor are functioning as opposed to malfunctioning due to degradation based on whether a response of the first intake air oxygen sensor during operating the engine in the second mode is greater than a first threshold and whether a response of the second intake air oxygen sensor during operating the engine in the second mode is greater than a second threshold, the first threshold and the second threshold set as a function of the first baseline response and the second baseline response.
1 more element
A system for a hybrid vehicle, comprising:
- an engine system including a variable displacement engine, an intake passage, an intake manifold, an exhaust, a set of cylinders, a set of pistons coupled to the set of cylinders, the set of pistons including piston rings, intake and exhaust valves mechanically coupled to each cylinder of the set of cylinders, a first variable displacement engine actuator configured to control positions of the intake valves and a second variable displacement engine actuator configured to control positions of the exhaust valves, a set of fuel injectors, each fuel injector of the set configured to provide fuel to each of the cylinders of the set of cylinders, and an engine temperature sensor;
- a crankcase ventilation system including a crankcase, a conduit selectively fluidically coupling the crankcase to the intake manifold, and a positive crankcase ventilation valve positioned in the conduit;
- a motor configured to rotate the engine;
- a first intake air oxygen sensor positioned in the intake manifold;
- a second intake air oxygen sensor positioned in the intake passage;
- a throttle positioned in the intake passage between the first intake air oxygen sensor and the second intake air oxygen sensor;
- and
- a controller storing instructions in non-transitory memory that, when executed, cause the controller to:
- with engine temperature below a threshold engine temperature, command fully open the throttle;
- rotate the engine in a forward direction fueled but without spark and with the intake and exhaust valves operating to open and close to obtain a first baseline response of the first intake air oxygen sensor and a second baseline response of the second intake air oxygen sensor;
- seal the cylinders while maintaining fueling to the cylinders and maintaining rotating the engine in the forward direction subsequent to obtaining the first and second baseline responses, wherein sealing the cylinders comprises closing the intake valves via the first variable displacement engine actuator and closing the exhaust valves via the second variable displacement engine actuator, and wherein sealing the cylinders routes un-combusted hydrocarbons from the injected fuel past the piston rings and through the conduit to the intake manifold via the positive crankcase ventilation valve, the positive crankcase ventilation valve in an open configuration as a result of the throttle being commanded fully open;
- and
- diagnosing whether the first intake air oxygen sensor and the second intake air oxygen sensor are functioning as opposed to malfunctioning due to degradation based at least in part on the routing of un-combusted hydrocarbons to the intake manifold.
10 more elements
Dependencies are inferred from the claim text.