what is the cause for the check engine light coming on? on 2008 Mercury Milan

check engine light is on and stays on.

Asked by for the 2008 Mercury Milan
2 answers
My thermostat was leaking antifreeze...easy to check if your reservoir is slightly low, but not enough to cause a change in temperature guage. Cost $385 to repair at the local ford Dealership.
Go to Autozone or Advance autoparts and ask them to check your engine light with the scanner,and then google it to see what the code P#### means