A method of tank leak diagnosis in a tank ventilation device including a fuel
tank
which is connected at least indirectly through a storage and tank ventilation valve
with a suction pipe of an internal combustion engine of the vehicle, with the storage
having an aeration conduit with a check valve, includes performing a tank leak
diagnosis by a negative pressure after turning off of the internal combustion engine;
and producing the negative pressure in the fuel tank immediately before the turning
off of the internal combustion engine.