operating system checksum

[97singlecab]

I read the tune out of a 2003 chevy with a 6.0 and a manual trans. It shows the operating system has a checksum error and advises not flashing. How do I fix this issue.21498

[97singlecab]

Or does someone have a good clean stock file I can use for this truck. Tried finding one online, but with tunefiledepot down, i'm not having much luck

[1FastBrick]

The OS appears to be very early for that VIN number.

12593058 is the latest updated OS for it. You can always verify here with the vin number https://tis2web.service.gm.com/tis2web

I only have the early one you show but from a 2WD.

I have the later one from a 4WD.

[joecar]

Thanks 1FB.

[joecar]

I read the tune out of a 2003 chevy with a 6.0 and a manual trans. It shows the operating system has a checksum error and advises not flashing. How do I fix this issue.21498Please post that tune file here.


Which V7 build version are you running (go Help->About)...?

[Blacky]

I read the tune out of a 2003 chevy with a 6.0 and a manual trans. It shows the operating system has a checksum error and advises not flashing. How do I fix this issue.21498

Re-read it and see if the checksum is good the second time. If so then discard the first read because it must have been corrupted while transferring from the ECM to the PC.

If it always gives the same failed checksum value then it is possible that the checksum has always been bad in the ECM but that someone has disabled the checksum validation in the ECM. In that case I recommend starting with a different, known good file. Then copying whatever calibration values you want/need from the bad file to the good file.

Regardless of how/why the checksum is bad you should never flash a file with a bad checksum into a controller. You should never "correct" the checksum unless you know for absolute certainty that the data in the file is not corrupt. Usually the only time that is true is when experienced tuners are modifying binary images using a hex editor and are simply using EFILive to correct the checksums after they have modified the data.

Regards
Paul

[1FastBrick]

Thanks 1FB.

No Problem! If my cables weren't somewhere in the mail, I would have flashed the correct updated stock tune for that Vin read it out with EFI and uploaded it here.

I also noticed it said it was a Manual calibration. Thats kind of rare.

[joecar]

Yes, that is quite rare.