Patent ID: 6250288
Filing Date: 2001-06-26
Classification: F02M

Abstract:
A method for checking the operability of a tank-venting system of a vehicle having an engine, the tank-venting system including: a tank; an adsorption filter having a venting line; a first connecting line connecting said adsorption filter to said tank; a tank-venting valve; and, a second connecting line connecting said tank-venting valve to said adsorption filter, the method comprising the steps of:providing a pressure source and operatively connecting said pressure source to said tank-venting system;determining and storing a first fill level of said tank at the start of a standstill of said vehicle;introducing an overpressure relative to atmospheric pressure into said tank-venting system during said standstill of said vehicle;detecting an operating characteristic variable of said pressure source as said overpressure is introduced into said tank-venting system;drawing a conclusion as to the presence of a leak in said tank-venting system from said operating characteristic variable;determining and storing a second fill level of said tank at the end of said standstill of said vehicle;forming the difference of said first and second fill levels and determining whether said difference is less than a pregiven threshold value; and,only if said difference is less than said threshold value, outputting a fault announcement.