2003 Ford F-150 thanks for the reply

Thank you I will take my car as soon as I can to autozone for the free diagnostic, Although now since I last emailed a question. My truck now is kind of doing a jerk motion I did not drive it any more since it started this but I am going to chance to autozone.I have changed the spark plugs myself and everything was fine for a week, then by coincidence, my check engine lite went on, I drove the truck for a few days and now am expieriencing this jerky motion and my overdrive light on the shift column is blinking like it will not switch in or somthing.I called the dealer to see if I can take this out which I have already seen in the library repair book, It says that to remove the 2 pronged button and exchange aknew, But the parts person sell the unit and harness to the column. Cant I just buy the new unit and exchange the new button with the old one only. And is all this tied to my problems.I appreciate any feed back and thank you