System and method to diagnose fuel system pressure sensor
AssigneeGM Global Technology Operations LLC
InventorsRobert Jackson, John F. Van Gilder
Life of this patent
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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.
Claims18
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, 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.
A method comprising:
- 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.
Dependencies are inferred from the claim text.