SMALL/GROSS LEAK CHECK
First Claim
1. A method of detecting a small or gross leak in an evaporative emission control system of an automotive vehicle comprising:
- purging said evaporative emission control system;
sealing said evaporative emission control system;
monitoring a vacuum switch coupled to said evaporative emission control system for an opening event due to a loss of a natural vacuum created in said evaporative emission control system;
determining if a leak check timer has exceeded a first or second predetermined threshold value if said opening event is detected; and
setting a first fault code indicating that said small leak has been detected if said leak check timer has not exceeded said first predetermined threshold value and setting a second fault code indicating that said small gross leak has been detected if said leak check timer has not exceeded said second predetermined threshold value.
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Accused Products
Abstract
A method is provided for detecting a small or gross leak in an evaporative emission control system of an automotive vehicle. The method includes initially purging and then sealing the evaporative emission control system. A vacuum switch coupled to the evaporative emission control system is then monitored for an opening event caused by a loss of a natural vacuum created in the evaporative emission control system. If said opening event is detected, the method determines if a leak check timer has exceeded a first or second predetermined threshold value. If the leak check timer has not exceeded said first predetermined threshold value a first fault code is set indicating that the small leak has been detected. If the leak check timer has not exceeded the second predetermined threshold value, a second fault code is set indicating that the small gross leak has been detected. The first threshold value corresponds to an amount of time required for a leak to be detected having a diameter of about 0.040 inches or greater. The second threshold value corresponds to an amount of time required for a leak to be detected having a diameter of about 0.070 inches or greater.
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Citations
19 Claims
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1. A method of detecting a small or gross leak in an evaporative emission control system of an automotive vehicle comprising:
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purging said evaporative emission control system;
sealing said evaporative emission control system;
monitoring a vacuum switch coupled to said evaporative emission control system for an opening event due to a loss of a natural vacuum created in said evaporative emission control system;
determining if a leak check timer has exceeded a first or second predetermined threshold value if said opening event is detected; and
setting a first fault code indicating that said small leak has been detected if said leak check timer has not exceeded said first predetermined threshold value and setting a second fault code indicating that said small gross leak has been detected if said leak check timer has not exceeded said second predetermined threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification