When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just a thought but I wonder if you changed your ECU from a "wrecker unit" or bought a new one and added that to your wrecker motor what they could check for then?
You will most likely have to find someone to flash it to work with your truck.
And something else that might not match, is the vehicles mileage vs the ecu mileage when you bring it into the dealer.