My first question or suspicion is why did someone trade it in at 14K? Must have had problems as you will take a bath trading in a new car with 14K on it. A bath!
Did the dealer give you any warranty? Obviously GM is not honoring the 5yr/100K since you are not the original owner.
You probably should have shut it down the first time and not tried to drive it home. Guess you don't have any roadside assistance?
I would never trust a car that has been cooked, so my advice, fix it and trade it in..to the same dealer, make it his problem
Run Forest, Run