Went to put a base tune into a friend's used truck that he just bought it is a 2003 Chevy Silverado 1500HD (LQ4 / 4L80E). It has a profile of:
Hardware 12570558
Operating System 12593058
Calibration 12579403

EFI Live read the tune from his PCM correctly and everything looked happy. After I changed a few parameters I went to write back the calibration and it said there was an error - the PCM had an incorrect serial # and it would have to have the OS flashed again.

It previously had a Hypertech tuner that we had, and I had "restored factory settings" but maybe it overwrote something in the past that it wasn't supposed to.

Should I try to reprogram the entire OS off his bad copy with my changes in it, or should I use one off the tune repository that might be a different OS but with the same calibration? A little at a loss here. Any input much appreciated! The tune I offloaded is attached.

 

Shut everything down, unplug everything, wait a few minutes and try again. Some times the flash corups and it fail safes like what your describing.

 

Sounds good I will try that later this week and see how goes. Thanks!