A vehicle carbon canister desorption diagnosis system and method

Abstract

The invention relates to the technical field of engine control, and provides a method and system for diagnosing desorption of a vehicle carbon canister. The method includes: detecting whether the engine is currently in a low-load working condition, and if the detection result is yes, performing low-load desorption diagnosis, First diagnose whether the check valve 2 is damaged and normally open, and then detect whether the low-load desorption pipeline is faulty; detect whether the engine is currently in a high-load condition, if the detection result is yes, perform high-load decarburization diagnosis, first diagnose Check whether the one-way valve is in a damaged normally open state, and then check whether the high-load desorption pipeline is faulty. Avoid low-load desorption pipeline fault detection when check valve 2 is damaged and normally open to improve the accuracy of low-load desorption pipeline fault detection, and avoid high-load desorption pipeline fault detection when check valve 1 is damaged and normally open Load desorption pipeline fault detection to improve the accuracy of high load desorption pipeline fault detection.

Description

technical field [0001] The invention relates to the technical field of engine control, and provides a vehicle carbon canister desorption diagnosis system and method. Background technique [0002] At present, with the vigorous development of my country's economy and technology, automobiles, as the most convenient mode of modern transportation, have gradually entered more and more families. Limited by a variety of technical problems and public recognition, although the country vigorously promotes new energy vehicles, so far the private car sector in my country is still dominated by gasoline-burning models. The use of gasoline requires a fuel system, whose function is to supply a certain amount of fuel to the engine that can be burned by the internal combustion engine to drive the movement of the car. Due to the volatile nature of gasoline, there is often a large amount of fuel vapor in the fuel system. Once these fuel vapors are unchecked and discharged into the atmosphere, t...

AI Technical Summary

Problems solved by technology

In the diagnosis of low-load desorption pipeline, this kind of scheme often causes the pressure change of the manifold to be insignificant due to the small desorption flow rate of the carbon canister, which easily leads to misjudgment of diagnosis.

And it is impossible to distinguish whether the no change in the detected pressure value is due to the failure of the desorption pipeline or the damage and jam of the one-way valve, which may easily lead to misreporting of faults and affect the reliability of diagnostic results

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