Patent ID: 8108127

Claim:
A method for checking the proper operation of a tank ventilation device for an internal combustion engine, comprising the steps of: detecting the position of a pressure switch of the tank ventilation device, wherein the pressure switch being in a low-pressure position if the pressure in the tank ventilation device is less than a specified threshold pressure, and otherwise being in a high-pressure position, when the internal combustion engine is running, opening at least partially a controllable tank ventilation valve of the tank ventilation device, which is arranged in a connecting pipe between a fuel-vapor storage system and an intake pipe of the internal combustion engine, and pneumatically connects the fuel vapor storage system and the intake pipe when in an open state, and pneumatically disconnects the fuel vapor storage system and the intake pipe when in a closed state, detecting the position of the pressure switch again after opening the tank ventilation valve, assessing the proper operation of the tank ventilation device on the basis of a comparison of the position of the pressure switch before opening the tank ventilation valve with the position of the pressure switch after opening the tank ventilation valve.