<p>The vehicle has a door that is to be opened against a driving direction. The door is attached to a door contact switch (1). An optical warning signal (2) is activated when an incorrectly closed door is fixed and opened rearwards. An acoustic warning signal (3) is output. An engine of the motor vehicle is controllable in such a manner that a critical speed is not exceeded. Additional brake interference is executable. The door is openable during the deceleration after reaching the critical speed.</p>
