In a method for operating a drive train for a motor vehicle including a transmission with a hydraulic torque converter having a converter lockup clutch which can be activated by a working pressure acting on a piston under engine overrun conditions when an increased internal pressure is produced in the torque converter which acts on the piston counteracting the operating pressure of the converter lockup clutch so that it cannot be closed, at least one operational variable of the motor vehicle is monitored and if the operational variable exceeds a threshold value the rotational speed ratio between the turbine wheel and pump wheel is reduced by changing the engine speed and/or the transmission ratio in order to activate the lock-up clutch.