1996 Cadillac DeVille
Why do my 1996 Cadillac DeVille keep saying
check coolant level
Because the coolant level in your coolant reservoir has dropped below its minimum level. Check the level and add coolant to bring it into the correct range.
I can smell antifreeze, I just put antifreeze in it the other day the coolant signal went off but now it's back on
You probably have a leak somewhere. Any obvious coolant on the ground after driving and letting the car sit for a few minutes? Any coolant showing at hose connections or around the radiator? Is your radiator cap on completely? If you see nothing, fill the reservoir up again and monitor its level as you drive the next few days. If it continues to lose coolant you may have a head gasket leaking into the engine or a cracked head or, worse, a cracked block.