Engine Coolant Light 98 W210

[phouse]

Hello all.. Is it ironic, that when the engine coolant low warning light comes on I get the check engine light along with the check engine electronics light at the same time... I had read somewhere that the coolant sensor is in series with the windshield wash low sensor.. I have enough of both I still get the coolant low warning.. I checked inside of the coolant tank and I see that t is half full, which is good ?/???? The Temp gauge is good. Where is the coolant level sensor at..? I can prob. figure out where the windshield sensor is.....