I can think of one cheap sure fired way to find out. Go to the local hardware store and have a copy made. Try to start the truck. If it needs the chip, it'll let you know.

You could always take it to the dealer. I need to get an additional key made as well. I also have key fobs from my '05 that look the same, but don't know if they can be programmed to my '03. Doubt it, but at over $100 each, it'll be worth the try. Just haven't had time.

Good luck!