307 1.6 hdi coolant level control warning

Selamunaleyküm friends 2006 1.6 hdi 110 gives a cooling water level control failure in my vehicle, but there is no water reduction, I followed it. Why does it do this? I would appreciate your help

The same thing has been happening to my car for a few weeks, it gives a warning on first start-up, sometimes it warns when driving on the road, I will remove the sensor and clean it, if it doesn't improve, the sensor will be changed.

I think it's from the sensor too, but I didn't know, I've never encountered it before, do you know where the sensor is?

It is mounted on the spare water tank, the cooling water container, the socket is visible, I will remove it and clean it, I will write the result on Sunday

Thank you, I'll have a look tomorrow morning

My car got better, if the water is not missing, cleaning the sensor fixes it.