Radiator overflow reservoir on 2005 Kia Sedona

My radiator overflow reservoir is low or empty and the check engine light comes on. When I refill it, the light will go off.

Asked by for the 2005 Kia Sedona
There is a sensor in the tank to read the coolant level, it will turn the light on to warn you, once you refill it then the fault goes away. The check engine light will come on for sometimes hundreds of codes. My next question would be, where is your coolant going.
I don't know. I haven't noticed any leaks. I'm now hearing noise from the right side around dash when heat is on.