hey guys newbie here. i have an 06 f150 crew cab fx4. i was driving this past sunday and my temp guage kept going to cold and back up to normal then it finally just stayed at cold. the air also quti working. i hooked it up to the computer and it said it was the cylinder head temp sensor, so i replaced it and the guage is still not working and now its saying its the pcm. what in the world is going on?