Definitely sounds like a passlock issue. Passlock "shows" the code value during crank, not before or after. If I remember right, the programming instructions tell you to press the button to "learn" the code after it's running. Well if you do that, there is no code to learn because the truck isn't cranking anymore. Give this a shot:
Try reprogramming the XK06, but before you start the process, try this....
-Before you start the programming procedure, turn the key to ignition(dont start), set your parking brake, and put the truck in drive(D), turn the key off.(It will stay in the ignition)
-Now go through the programing sequence only where it tells you to push the button after the truck is running, press and hold the button as you turn the key as if you were to start the truck.
The reason you put it in drive is that way the truck won't actually crank, but the resistor code will still be sent down the passlock wires.
Worked for me when I was having trouble with a '99. If you find that it still doesn't work, you can always just learn the resistor value and go old school and use a matching resistor and relay for remote start. Or just put the resistor in with no relay and be able to get keys copied anywhere