Verfahren zur Diagnose des Tankentlüftungsventils

摘要

The invention relates to a method for testing the operativeness of a tank ventilation valve between a combustion engine and a fuel vapour storage device. According to the method, the stored fuel vapour is fed from the fuel vapour storage device to the internal combustion engine when the tank ventilation valve is open, the supply of fuel vapour representing a first flow of energy to the combustion engine, and air also flows to the internal combustion engine via a throttle valve, a second flow of energy being associated with this air. Means are provided for keeping the sum of the two energy flows at a predetermined value and the tank ventilation valve is actuated for opening. A change in the energy flow delta E resulting from the opening actuation is determined by the throttle valve and compared with a predetermined threshold. A slight change in the energy flow that does not exceed the threshold value (threshold) is considered an error.