Automatic ligths no function (Rain Sensor)

Question

Hello

On Mercedes W204 008 I have problem with rain sensor. It works fine with  windshields, but the automatic ligths doesn´t work, and I get an error- automatic lights no function.

Is that a problem of the sensor or is it something else? I need 100% shure that is a sensor problem.

Can I get a new one, and replace it? Do I need some kind of calibration sensor?

Thank you in advanced.