When I first got my Express a few weeks ago, it did not come with key fobs so I called the local dealership. I gave them my vin and was told that it was not set up for RKE and that there was no way to factory add it and that I should look into aftermarket RKE. I do have factory power locks, power windows, and TPMS. Then later I was playing with the DIC menus and found that there are options in there for RKE settings (lights/horn flash, which doors to unlock, etc.). So I called 3 more dealerships and gave them the VIN and all 3 told me that all I had to do was buy the key fob and have it programmed and that the van is indeed set up for it. So I guess the first one was mistaken. The last dealership told me that some models can be set up easy and some require an hour plus of labor to hook it up to the computer to program it. I’m also seeing aftermarket transmitters that claim to work with factory RKE systems. Anyone been through this?

 

I would buy a fob and go for it, you can get a pair off ebay for like $10. There are several methods of programming them, you'll just have to figure out which one works for your truck, most likely you will be able to do it yourself.