Ok, I literally just found mine 5 minutes ago. I'll try to give detailed instructions for finding it. It IS
on the computer module behind the passenger kickplate.
1. First remove the fuse panel. I removed the floor mat to make it easier.
2. Then remove the threshold (door sill). Its just held on with clips. It pops off really easy.
3. The passender kickplate is just held on by the weather stripping and the threshold, so once you remove the threshold and pry the weather stripping from on top of the lip of the kickplate, it will simply come away from the truck.
4. The computer module is the black box held on with a couple of screws in the body of the truck. You will have to remove the "wiring harness" that is connected to the box. Its a "white" plastic thing with a bunch of wires coming out of it. its just held on with 2 pegs. A Flathead will do the trick. this will make room for tools and such.
5. The screws holding the computer to the body have a 9/32 hex head, so keep that in mind when you are choosing tools.
6. Remove the two screws (one in front and top, the other is underneath). Once the screws are out the module will NOT come away from the body but simply be able to pull away a little bit. This is just enough to see the number.
7. Get your good flashlight, and look on the back of the module (facing away from the truck. There will be a sticker on the back with a big C
on it. the sticker will be upside down. Look in the top right corner (lower left if the sticker was right side up). There will be a 5 digit number. THIS IS IT!!! CONGRATS!
I put this post up because I had hell trying to get this number, and like to help others. I hope I have. My dealer wanted $55. I refuse to pay that, especially since all it took was a little information, patience, and determination. Good Luck.