I converted from an 0411 to a p59 pcm for flex fuel on my vehicle. I found a file from an 04 tahoe that had flex fuel enabled. It was a 12587603 os number. so my tuner used some gm cable to flash my ecu ( 05 express van part #12586243) with the 04 flex fuel tahoe file so I wouldn't have to spend 4 credits. after pcm was flashed i licensed the tahoe file . everything works but my reverse lockout doesn't work so I figure i have to segment swap for a t56. But when i go back to try and find a matching OS there isn't one. my OS number changed from 12587603 to 12606960. Is that normal for it to change after license ? I'm hoping i won"t have to spend another $200 just to get my reverse lockout working normal.