SYSTEMS AND METHODS FOR INDICATING CANISTER PURGE VALVE DEGRADATION
First Claim
1. A method comprising:
- monitoring a fuel vapor loading state of an adsorbent material positioned in an engine air intake while fuel is being added to a fuel tank that supplies fuel to the engine; and
responsive to an indication that an increase in the fuel vapor loading state is greater than a first predetermined threshold;
indicating a canister purge valve configured to seal the fuel tank from the engine air intake is degraded.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and systems are provided for indicating whether a canister purge valve in a vehicle evaporative emissions control system is degraded. In one example, an air intake system hydrocarbon (AIS HC) trap temperature may be monitored during a refueling event, and responsive to an indication that the AIS HC trap temperature change is greater than a predetermined threshold, it may be indicated that the canister purge valve is degraded. In this way, diagnosis of whether a vehicle canister purge valve is degraded may be indicated without the use of engine manifold vacuum, and may be advantageous for vehicles configured to operate for significant amounts of time without engine operation, or without intake manifold vacuum.
13 Citations
20 Claims
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1. A method comprising:
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monitoring a fuel vapor loading state of an adsorbent material positioned in an engine air intake while fuel is being added to a fuel tank that supplies fuel to the engine; and responsive to an indication that an increase in the fuel vapor loading state is greater than a first predetermined threshold; indicating a canister purge valve configured to seal the fuel tank from the engine air intake is degraded. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method comprising:
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monitoring a fuel vapor loading state of an adsorbent material positioned in an engine air intake while fuel is being added to a fuel tank that supplies fuel to a vehicle engine; and responsive to an indication that an increase in the fuel vapor loading state is greater than a first predetermined threshold but less than a second predetermined threshold; indicating a canister purge valve configured to seal the fuel tank from the intake manifold is degraded, and not actively purging the adsorbent material; and responsive to an indication that an increase in the fuel vapor loading state is greater than the first predetermined threshold and greater than the second predetermined threshold; indicating the canister purge valve configured to seal the fuel tank from the intake manifold is degraded, and actively purging the adsorbent material. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A system for a hybrid vehicle, comprising:
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an engine comprising one or more cylinders, each cylinder including an intake valve and an exhaust valve; fuel injectors for each of the one or more cylinders; a spark plug for each of the one or more cylinders; an engine exhaust; a fuel vapor canister selectively coupled to an engine intake manifold via a canister purge valve; a fuel tank that supplies fuel to the engine, the fuel tank selectively coupled to the fuel vapor canister via a fuel tank isolation valve; an air intake system hydrocarbon trap positioned in the engine intake manifold; one or more temperature sensor(s) positioned in the fuel vapor canister; one or more temperature sensor(s) positioned in the air intake system hydrocarbon trap; and a controller configured with instructions stored in non-transitory memory, that when executed cause the controller to; responsive to a request for refueling of the fuel tank, command open the fuel tank isolation valve; command closed or maintain closed the canister purge valve; monitor temperature of the air intake system hydrocarbon trap during refueling of the fuel tank; and indicate the canister purge valve is degraded responsive to a temperature increase in the air intake system hydrocarbon trap above a first predetermined threshold. - View Dependent Claims (19, 20)
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Specification