Dealer's fulla bull; Google "AJR International," they programmed my trip computer, no problem! I explained my situation to them, that I needed my 5-button DIC programmed to match my original DIC's miles, and they agreed! Had to send in both units-and I paid for my own shipping, too-but I paid a whopping $80!
P.S: their phone number will be on their website; they do programming work for a multitude of GM vehicles' computer systems.