2000 Cadillac Deville engine hot message

You need to first make sure that you have all of your fluids topped off and then take it to autozone and get a free engine scan and repost your findings

Ck you waterpump belt and pump, to scan codes go through your heater, off and warmer or off and down on the mode button at the same time, with your key in the on position

Ok your gonna need to bleed your system out. Sounds like you have an air pocket, which is why your not gettin heat. While the engine is cool, take your coolant cap off, and start the car and put the heater on high, let the car come to operating temp. While this is happening the coolant will begin to bubble, that is the air coming out. Also be sure to open the over flow container too. After about 10-15 minutes. Shut car off and top off coolant. Put cap back on. And you should be good to go, if not repeat the steps and do it for just a few minutes longer.

If you scaned your codes the way I asked you to do through your heater/AC controls you will get the codes, you dont need autozone, they can only scan PCM codes I need the Body codes, and it is vary hard to get an air pocket in this system, if you have low coolant you still have a leak somewhere

But it is still possible, correct?

Not on this car