A procedure for dosing a reducing agent into the exhaust gas of an combustion engine with a valve is presented, which shows a solenoid and a movable seal body for adjusting a percolation profile, whose value is depending on the current through the solenoid, whereby the valve is triggered by a current profile, which shows two consecutive sectors. The procedure distinguishes itself in that it is checked in the first sector whether the valve is frozen or whether a danger of freezing exists, and that an electric energy that has been fed into the solenoid with the electric current is set in the second sector depending on the result of the checking. Furthermore a controller is introduced, which is customized for controlling the process of such a procedure.