Tank-venting system in a motor vehicle and method for checking the operability of the tank-venting system

Abstract

A method checks the operability of a tank-venting system for a motor vehicle having an internal combustion engine. The tank-venting system includes a fuel tank (10), an adsorption filter (20) and a filter line (12) connecting the adsorption filter to the fuel tank. The adsorption filter (20) has a venting line (22) and a switchover/check valve (70) is provided for closing off the venting line (22). The system includes a tank-venting valve (90) and a valve line (24) connecting the tank-venting valve to the adsorption filter. In the method, an overpressure relative to atmospheric pressure is introduced into the tank-venting system utilizing a drivable pressure source (50). An operating characteristic variable of the pressure source is detected while introducing the overpressure to determine the pressure course. A conclusion is drawn as to the presence of a leak from the pressure course. The overpressure is reduced by opening the tank-venting valve (90) and simultaneously closing said switchover/check valve (70).

Dependencies are inferred from the claim text.