Patent ID: 6820466
Filing Date: 2004-11-23
Classification: F02M

Abstract:
A method for checking the tightness of a tank system of a vehicle, the method comprising the steps of:switching off the engine of said vehicle and then blocking the tank of said tank system utilizing blocking means without first introducing an overpressure or underpressure into said tank system; thereafter, detecting the passively developed pressure in the blocked-off tank system with a pressure sensor to obtain a trace of said pressure over time; drawing a conclusion as to the presence of a leak from said trace; drawing a conclusion as to a tight tank system when said pressure passes either a pregivable underpressure threshold value or a pregivable overpressure threshold value after the elapse of a pregiven waiting time; and, varying the underpressure threshold value and the overpressure threshold value in dependence upon parameters which characterize ambient influences.