Patent ID: 7980229

Claim:
A tank ventilation system for a motor vehicle, comprising: a tank for combustible fuels, a vapor chamber being defined in parts of the tank that are not occupied by the combustible fuels; a filler neck extending from an external environment to the tank to enable filling of the tank with the combustible fuel; a tank cover removably mounted on the filler neck; a differential pressure sensor for measuring a pressure difference between the vapor chamber of the tank and the environment; a connecting line for deaearation communicating with the vapor chamber, the connecting line being formed without a vacuum valve; a mechanical vacuum valve being provided in the tank cover and separate from the connecting line for providing direct communication from the environment to the tank, the mechanical vacuum valve being configured for tank aeration with respect to the environment; an activated carbon filter communicating with the connecting line for adsorption of hydrocarbon vapors of the tank; an electrically activatable check valve in the connecting line between the vapor chamber and the activated carbon filter, the check valve being closed if the pressure difference measured by the differential pressure sensor is below a fixed, positive threshold value, and being open if the pressure difference is above the threshold value.