CPC F02M 25/0836 (2013.01) [F02M 25/0809 (2013.01); F02M 25/0854 (2013.01)] | 20 Claims |
1. A method for operating a fuel tank arrangement for a motor vehicle, the fuel tank arrangement having a fuel tank, a hydrocarbon filter and a pump, wherein the fuel tank is fluidically connected via a tank shut-off valve to the hydrocarbon filter and the hydrocarbon filter is fluidically connected, on the one hand, via the pump to an external environment of the fuel tank arrangement and, on the other hand, via a purge valve to an intake tract of an internal combustion engine, wherein there is a series connection between the hydrocarbon filter, the pump, and an opening to the external environment configured to permit fluid flow from the hydrocarbon filter, through the pump, and out the opening to the external environment,
wherein the method comprises carrying out a first leakage test mode when the pressure present in the fuel tank is greater than a pressure threshold value, comprising closing a shut-off valve arranged in terms of flow between the pump and the external environment and opening the tank shut-off valve and then, during a test period, measuring the pressure in the fuel tank by a pressure sensor arranged in the fuel tank and, if a differential threshold value is exceeded, detecting a leakage of the fuel tank arrangement by a pressure difference of a pressure drop of the pressure over a specific period of time.
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