System and method to diagnose fuel system pressure sensor
First Claim
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1. A system comprising:
- a pressure sensor that generates a first pressure signal indicating a first pressure within a fuel system of an engine when the engine is started and when a purge valve of the fuel system is closed; and
a controller configured to;
detect when the engine is started,determine an amount of variation in the first pressure signal over a first period,determine a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period, anddetermine that the pressure sensor operates normally if the amount of variation in the first pressure signal is less than a first threshold and that the pressure sensor is faulty if the amount of variation in the first pressure signal is greater than or equal to the first threshold,wherein the first threshold is determined based on a leakage rating of the purge valve, andwherein the leakage rating of the purge valve is non-zero.
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Abstract
A system includes an ignition detection module, a pressure sensor, a pressure variation module, and a pressure sensor diagnostic module. The ignition detection module detects when an engine is started. The pressure sensor generates a first pressure signal indicating a first pressure within a fuel system of the engine when the engine is started and when a purge valve of the fuel system is closed. The pressure variation module determines an amount of variation in the first pressure signal over a first period. The pressure sensor diagnostic module determines a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period.
84 Citations
18 Claims
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1. A system comprising:
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a pressure sensor that generates a first pressure signal indicating a first pressure within a fuel system of an engine when the engine is started and when a purge valve of the fuel system is closed; and a controller configured to; detect when the engine is started, determine an amount of variation in the first pressure signal over a first period, determine a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period, and determine that the pressure sensor operates normally if the amount of variation in the first pressure signal is less than a first threshold and that the pressure sensor is faulty if the amount of variation in the first pressure signal is greater than or equal to the first threshold, wherein the first threshold is determined based on a leakage rating of the purge valve, and wherein the leakage rating of the purge valve is non-zero. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method comprising:
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detecting when an engine is started; generating, using a pressure sensor, a first pressure signal indicating a first pressure within a fuel system of the engine when the engine is started and when a purge valve of the fuel system is closed; determining an amount of variation in the first pressure signal over a first period; determining a state of the pressure sensor based on the amount of variation in the first pressure signal over the first period; determining that the pressure sensor operates normally if the amount of variation in the first pressure signal is less than a first threshold and that the pressure sensor is faulty if the amount of variation in the first pressure signal is greater than or equal to the first threshold; and determining the first threshold based on a leakage rating of the purge valve, wherein the leakage rating of the purge valve is non-zero. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification