Patent ID: 8631689

Claim:
A method for the functional testing of a pressure switch of a tank vent device for an internal combustion engine of a motor vehicle, with the pressure switch being located in a low-pressure position if the pressure in the tank vent device is lower than a pressure threshold, and said pressure switch otherwise being in a high-pressure position, the method comprising: in an operating state in which a crankshaft of the internal combustion engine rotates and the pressure in an intake pipe of the internal combustion engine exceeds the pressure threshold, actuating a tank vent valve of the tank vent device, said valve being disposed in a connecting line between a fuel vapor reservoir and the intake pipe, in such a way that the tank vent device and the intake pipe are pneumatically connected, assessing the pressure switch as defective if the pressure switch is in the low-pressure position after actuation of the tank vent valve.