I have the keyless one , same as limecharger, sport, I have has a problem once in a while. Hold it right at the door or the start button and try it.
I have taken mine apart a few times and cleaned it up with a fine tooth brush, just don't get the board wet, rubber , plastic parts you can use soap and water. Make sure everything is dry before installing the battery, and battery connections is usually the problem, a rubber pencil eraser works good to polish them up, fingerprints , oil on the battery is not good.
This does not really answer the question, but I have had the fob not detected, some times in the off side pocket, If I put it in the pocket closest to the truck it will work ( to open the doors)
I have keyless doors as well.
The owners manual tells you about holding up to the start button , with a dead battery.
I have never done any thing to the truck itself, so no help on that, Sorry.