2002 tune on 99 pcm

[laurieandmike]

is it possible if so how?
thanks

[Ben E]

Yes, the OS' are interchangeable on the 99-02 PCMs. I'm still attempting to figure a good way of doing that myself. I did write an 02 file to my truck but it wouldn't start as I think the VATS system was preventing me from doing that so I just went back to my original file as I was a tad scared of why my truck didn't start. Now, the only issue I can see is with HP Tuner's software it's not possible to have a VIN/OS mismatch. So a VIN on your 99 truck cannot be on the 02 file, vise versa, a 02 pcm/truck cannot have a VIN from 99 truck. 1999-2000 have the same computer and OS, 2001-2002 have the same computer and OS.

So if you want the VIN to match the vehicle it's technically not possible through the HP Tuners software.