Engine light on for a ford expedition don't know why?

Engine light on for a ford expedition don't know why?

And no one here knows why either. This is because your car is "throwing a code" - some problem has arisen and the computer is picking it up. The codes need to be read by someone with the appropriate equipment. Outfits like Pep Boys and Autozone will often read codes for free in hopes that you will let them fix it. Good business practice.