I just did one. turn key on and off 8 times, leaving it on the 8th time. press any button on remote. it's now programmed.

 

The number on the back of the fob is a model number.
Each fob contains a unique code.
There is a procedure to perform to have the computer accept the codes from the fobs.
Year of vehicle should work for ordering new fobs or find someone else with the same year vehicle.
I would order two fobs from ebay and code them both in, the seller should include the procedure.
Not sure if the procedure for mine is the same as yours - do you have a 2015?
This forum is for 1997-2003 trucks.
For my vehicles the procedure works fine, but if you have one fob entered you can't add another one.
I think when the procedure starts is erases all current fob codes and starts storing new fob codes.

 

Thanks for the reply. I have both a 2015 and a 2002 but need the fobs for the 2002.

 

Did your fobs have 3 or 4 buttons?
Our 2002 has 3 and the 2003 has 4 buttons.
The fobs are about $4/ea on ebay.
If you have 2 keys I recommend getting at least one more key, too.
It takes 2 unique key codes to add more without going to the dealer or locksmith.
The keys have unique codes (unless it's a clone) and can be added with a different procedure.
If you go to your User CP - Edit Signature both your vehicles can be listed at the bottom of your posts.

 

I broke one key but still have one left. Guess I should get another one then head to the dealer to get it programmed to the truck.

thanks for the advice, it is very useful.