| 摘要 |
A tank-venting system includes an active charcoal filter (20), which is connected to a tank (10). An intake manifold (40) of an internal combustion engine is connected to a tank-venting valve (30). The active charcoal filter (20) stores fuel vaporized in the tank (10). When the tank-venting valve (30) is driven open by the control unit (60), air from the ambient is drawn by suction through the active charcoal filter (20) and the fuel stored therein is released to the inducted air. A pump (50) is provided for checking the tightness of the tank-venting system and is connected to the control unit (60). A switchover valve (70) is connected downstream of the pump (50). A reference leak (81) is arranged in parallel to the switchover valve (70). A throughflow sensor (90) and a temperature sensor (91) are connected forward of the pump (50) which detect the scavenging air quantity, which is used to scavenge the active charcoal filter (20), as well as the intake air temperature. The sensors transmit the scavenging air quantity and the temperature to the control unit (60). Based on the scavenging air quantity and the intake air temperature, the control unit determines whether the pump (50) is iced at the particular time point. In case of a determination of "iced", the tightness measurement is not enabled by a control signal and/or the output of a fault signal, which indicates non-tightness of the tank-venting system, is suppressed.
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