Patent ID: 6446615
Filing Date: 2002-09-10
Classification: F02M

Abstract:
A method for checking the operability of a tank-venting system of a motor vehicle including checking the tightness thereof, the tank-venting system including a tank, an adsorption filter, a connecting line connecting the adsorption filter to the tank, the adsorption filter having a venting line, a tank-venting valve, a valve line connecting the tank-venting valve to the adsorption filter and a pump module connected to the adsorption filter, the method comprising the steps of:operating said pump module from time to time to introduce an overpressure relative to atmospheric pressure into said tank-venting system; detecting the course of at least one operating characteristic variable of said tank-venting system indicative of the pressure therein when introducing said overpressure; from said course, drawing a conclusion as to the presence of a non-tightness of said tank-venting system; outputting a corresponding fault signal when a condition of said non-tightness is present in said tank-venting system; inducting scavenging air from the ambient of said vehicle and scavenging said adsorption filter with said scavenging air from time to time for regenerating said adsorption filter; detecting the temperature of said scavenging air and the quantity of said scavenging air supplied to said absorption filter during scavenging of said adsorption filter; and, drawing a conclusion from at least one of said temperature and said quantity as to whether said pump module is in one of the following states: frozen, thawed or demoisturized.