[rodster]

The programmer comes with very good step-by-step instructions. Just follow them and you'll do fine.

The only pain in the butt part is you have to pull your OnStar fuse while you're programming. That fuse is in the fuse box in the engine bay on the driver side, just aft of the battery. Look in your owner's manual for which fuse is OnStar. As I recall, it's in or near the lower right corner of the fuse box if you're looking in from the driver's side of the truck.

Whatever settings you choose to start with, it's best to have them printed and with you when you start the programming. Before I started, I read the thread that H2 Rocks posted a link to. That got me confused so I asked Phil at Trail Duty what he recommends. The settings I used are the same he uses.

The whole operation should take you about 15 minutes the first time. After that, well under 10. You'll likely change the tire size a few times to get it right.