What is the working principle of an automotive activated carbon canister?

[AthenaAnn]

Working principle of an automotive activated carbon canister: When the engine is running, the ECU controls the opening and closing of the carbon canister solenoid valve based on signals such as engine speed, temperature, and air flow to regulate the vacuum level in the upper part of the emission control valve, thereby controlling the valve's opening degree. When the emission control valve opens, fuel vapors are drawn into the intake manifold through the valve to participate in combustion. Precautions for the activated carbon canister: Car owners may encounter difficulties in engine startup due to an overfilled fuel tank, which could indicate an issue with the gasoline evaporation control system where the carbon canister is located. A constantly open carbon canister solenoid valve allows all fuel vapors in the tank to enter the intake manifold, causing the engine control unit to detect an overly rich air-fuel mixture and preventing startup. A constantly closed solenoid valve leads to saturation of fuel vapors in the carbon canister, with excess vapors escaping directly into the atmosphere, resulting in strong gasoline odors inside the vehicle and other related issues.