the DHP only supports the newest OSID's for each year make model trim. if the car never had the pcm updated from the dealer and has an early OSID the tuner will reject the file. You can use the cars VIN to check the correct OSID for it. http://tis2web.service.gm.com/tis2web then if you have that OSID, just do a full write over top of the existing file.