Plug it in to any obdII diagnostic port on any so equipped vehicle. On the screen it will give some code that refers to what mode it is in. Can't remember the codes but as I recall they were self explanatory, ex=extreme, r=race, t=towing...
If it is local you can just try it and see if it will load on your truck.
If it is local you can just try it and see if it will load on your truck.