To re-syncro the keys TRY this

Get in truck
Shut door
Insert the key that you want to syncronize into the ignition
Turn the ignition switch on completely (not to start) & then back off
Remove key
Hold the lock button on that KEY down & don't release
press the un-lock button 5 times (quickly) while holding the lock button
release the lock button & press the lock OR un-lock button 1 more time..
THAT should re-syncro that key.

OF course you have to do that complete process in LESS than 10 seconds from start to finish!!

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