Leak detection based on fuel level
First Claim
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1. A method for a vehicle with an engine, comprising:
- during an engine-on condition, delivering fuel from a fuel tank to one or more cylinders of the engine while the fuel tank is sealed off from atmosphere; and
indicating a leak based on pressure in the fuel tank being less than a threshold during an engine-on event where the engine-on event is subsequent to an engine-off condition following the engine-on condition.
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Abstract
Methods and systems for fuel system leak detection are disclosed. In one example approach, a method comprises, during an engine-on condition, delivering fuel from a fuel tank to one or more cylinders of the engine while the fuel tank is sealed off from atmosphere, and indicating a leak based on pressure in the fuel tank. For example, a leak may be indicated in response to a pressure decrease in the fuel tank greater than an expected pressure decrease, where the expected pressure decrease is based on a fuel level in the fuel tank.
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Citations
19 Claims
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1. A method for a vehicle with an engine, comprising:
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during an engine-on condition, delivering fuel from a fuel tank to one or more cylinders of the engine while the fuel tank is sealed off from atmosphere; and indicating a leak based on pressure in the fuel tank being less than a threshold during an engine-on event where the engine-on event is subsequent to an engine-off condition following the engine-on condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for a vehicle with an engine and an evaporative emissions control system, comprising:
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while operating the engine, delivering fuel from a fuel tank to all engine cylinders at a fuel flow rate above a non-zero upper threshold while the fuel tank is sealed off from atmosphere; and indicating a leak in the evaporative emissions control system based on a pressure decrease in the fuel tank greater than an expected pressure decrease, where the expected pressure decrease is based on a fuel level in the fuel tank. - View Dependent Claims (14, 15, 16)
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17. A method for a vehicle with an engine, comprising:
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during an engine-on condition, delivering fuel from a fuel tank to one or more cylinders of the engine at a fuel flow rate above a non-zero upper threshold while the fuel tank is sealed off from atmosphere; and during an engine-off condition subsequent to the engine-on condition, maintaining the fuel tank sealed off from the atmosphere and indicating a leak in response to a pressure decrease in the fuel tank greater than an expected pressure decrease, where the expected pressure decrease is based on a fuel level in the fuel tank. - View Dependent Claims (18, 19)
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Specification