A method includes determining failure of a drive energy store of a vehicle and activating generator operation of a electric main engine as a result of the failure. The method includes determining a current driving condition of the vehicle, what actuators are necessary in order to put the vehicle into a safe operating condition, and what each of the necessary actuator dynamics are based on the current driving condition of the vehicle. The method includes determining a demand for electrical energy that is necessary for a particular necessary actuator to attain the safe operating condition, and regulating a proportionate generator operation of the electric main engine, taking into consideration electrical energy of the necessary actuators required for carrying out each of the necessary actuator dynamics. The method includes activating the actuators necessary for achieving the safe operating condition with the determined actuator dynamics until the safe operating condition is achieved.