If this truck uses tier 2spectrum and you do not have the software to go into the truck to get the codes because this truck has a emissions problem you can jump the diagnostic connecter l believe it is a and d than count the blinks it should be a three digit code. It will first go through a count down from l believe six to one three times than will give you the code. The.codes are all three digits they will repeat three times than if any other codes will go to the next code. Hope this was of help.