My understanding is that the truck's computer adjusts to the type of driving you do i.e. in town or highway towing. I have had several opinions but nothing conclusive as to whether or not the computer reprograms itself as you drive or whether you should pull over after a sort while after you first set out towing a trailer, turn the engine off, let the computer reprogram itself and then contuinue on.

 

Just drive it, it'll do the rest.