Method and apparatus for monitoring a valve deactivator on a variable displacement engine
First Claim
1. A method for determining if a valve deactivator on a variable displacement internal combustion engine is functioning properly comprising the steps of:
- checking for an asymmetry in a fuel mass calculation between two cylinder banks of the engine during fractional mode of engine operation;
checking for substantial symmetry in the fuel mass calculation between the two cylinder banks of the engine during maximum mode of engine operation; and
storing a valve deactivator fault code if an asymmetry exists during said fractional mode and substantial symmetry exists during said maximum mode.
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Accused Products
Abstract
A method and apparatus is provided for determining if the valve deactivator on a variable displacement internal combustion engine is functioning properly. The occurrence of an asymmetry in one of the cylinder banks when making fuel mass calculations during the fractional mode (four cylinders) and the presence of substantial symmetry in fuel mass calculations during maximum mode (eight cylinders) of engine operation indicates a possible deterioration of the valve deactivator. Also, if the ratio of the difference between the expected MAP and the actual MAP during fractional cylinder mode and maximum cylinder mode exceed a calibratable value possible valve deactivator deterioration is also indicated. In a preferred embodiment, these two monitoring methods are combined to provide a more robust indicator, so that if both indicate a possible problem, then an indicator lamp is illuminated to signal that service personnel should check whether the valve activators are properly functioning.
50 Citations
12 Claims
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1. A method for determining if a valve deactivator on a variable displacement internal combustion engine is functioning properly comprising the steps of:
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checking for an asymmetry in a fuel mass calculation between two cylinder banks of the engine during fractional mode of engine operation; checking for substantial symmetry in the fuel mass calculation between the two cylinder banks of the engine during maximum mode of engine operation; and storing a valve deactivator fault code if an asymmetry exists during said fractional mode and substantial symmetry exists during said maximum mode. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Apparatus for determining if a valve deactivator on a variable displacement internal combustion engine is functioning properly comprising:
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a computer; sensor means supplying data to said computer; said computer using said data for calculating fuel mass for two cylinder banks of the engine during fractional mode of engine operation and during maximum mode of engine operation; said computer detecting when a difference between a fractional mode calculation for one cylinder bank and a fractional mode calculation for the other cylinder bank exceeds a stored value, said computer detecting whether the absolute value of a difference between a maximum mode calculation for one cylinder bank and a maximum mode calculation for the other cylinder bank is less than a stored value; said computer storing a valve deactivator fault code both of said differences are detected. - View Dependent Claims (8, 9, 10)
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11. A method for determining if a valve deactivator on a variable displacement internal combustion engine is functioning properly comprising the steps of:
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checking for an asymmetry in a fuel mass calculation between two cylinder banks of said engine during fractional mode of engine operation; checking for substantial symmetry in the fuel mass calculation between the two cylinder banks of the engine during maximum mode of engine operation; storing a valve deactivator code if an asymmetry exists during said fractional mode and substantial symmetry exist during said maximum mode; wherein a predetermined number of checks for asymmetry must be performed in order to make a decision on whether to store said code; wherein fractional mode asymmetry must exist for a predetermined percentage of the number of checks for asymmetry; wherein the code stored identifies the bank of cylinders where the asymmetry exist; and wherein asymmetry exist if a difference exist between a ratio of short and long term correction factors on one bank of cylinders and a ratio of short and long term correction factors on the other bank of cylinders and said difference exceeds a calibratable value. - View Dependent Claims (12)
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Specification