Welcome
There is a handy tool here at Automotiveforums.com......the search tool.
There have been alot of posts about codes coming up on X's. Most people either unplug their negative battery terminal, which removes the computers memory or they take their truck(yes truck....it's not a car)to Pep-Boys or the like and they read codes for free. They'll also cancel out the codes for free. I'd suggest doing the later because you don't know what is causing the light to be on. Pretty simple fix, nontheless.