In a process for controlling a closing device in a motor vehicle driven by an electric motor, in particular for controlling a motor vehicle sunroof, to protect a body part from being crushed during a closing motion, a closing resistance variable is detected. With some implementations, an instrument is provided with an illumination system having a light source and a light diffusion device proximal to the light source. A plurality of images obtained by the shooting are combined together to generate a combined image of the object. The flange has bearing surfaces formed thereon along which the flange is mounted to the second element. Stationary contacts that are repeatedly contacted, are in the form of wires with fixed first end and with free or fixed second ends. Even though the liquid level in the discharge vessel is largely fluctuated, the liquid level in the storage vessel is almost never done.