CEl Light Question

OK fellas, quick question. My CEL light and Slip Control light are on together, which I know that they sort of go hand and hand. What's wierd to me is that the lights will come on and stay on for a day or two then I'll crank the truck up and they'll be gone for a while. Sort of an intermittent problem. Has anyone had this happen with their truck before? Just looking for somewhere to start or an idea. Thanks in advance for any responses. I've been a long time lurker for a long while now and have gotten many many ideas from this awesome forum.

 

My lights just came on yesterday @47800 miles and my fault code is P2237. Start by going to auto parts store and see what fault code your truck has