I am pretty new to ECU tinkering and I am soaking up knowledge like a sponge.  This forum is a gold mine!  Anyhow I am looking to make some modifications to my GIAC K04 flashed ECU.  Namely, I am deleting SAI/N249/EVAP/PCV, and looking to delete the readiness checks from my tune.  I've found some good information on this topic already.  After I produce a flash (.bin) using WinOLS, ME7Check.exe tells me there are 2 checksum errors.  WinOLS seemed to have no problem producing the .bin file and I was even prompted to update the checksums, which I allowed.  Should I be worried about this?  Should I not flash it back to the ECU?

Here's what I've done so far:
- Used NefMoto ME7 ECU Flasher 1.8 to read my GIAC tune via ODBII.
- Located the stock ECU file for my car VW 20th anniv. GTI (06A906032PL)
- Started a new project in WinOLS using the stock file.
- Imported the GIAC file into WinOLS. (Recommended procedure to use checksums on a modded file)
- I made the edits at the proper offsets for SAI/EVAP deletes.
- Saved the project and exported the new .bin
- Ran ME7Check.exe on the new bin, and it revealed 2 checksum errors.  However, when I look a the file in a Hex editor, it's clear that the checksums were updated.

I'm wondering if ME7Check.exe is wrong here.  (I should point out even the unmodified GIAC flash from my ECU already had 1 Checksum error.) Or perhaps GIAC based their flash on a different ECU which happens to work on mine?  WinOLS is using the OLS262 checksum package.  When comparing the GIAC file to the stock file, they share a lot of the same data in the same place. Any thoughts?

Hmm.  Good to know.  I do find it interesting that I started out with 1 checksum error with the original GIAC file and after making changes, ended up with 2 checksum errors according to ME7Check.exe.

If WinOLS says the file is good, then is it safe to assume I could flash it back to the ECU?  Afterall I only zeroed out a couple offsets.  I can zero out the same offsets on the stock ECU file and there no checksum errors according the ME7Check.exe

Yeah, gotta find a way to get my hands on a spare ECU.    I wonder how important it is to get the same ECU.  ie. 06A906032PL vs. 06A906032NK

Galetto should be coming in the mail to do any boot mode stuff if necessary.  Thanks!

Tony's flashing software can recover an 1.8T ECU witch is locked due to bad checksum i can confirm that. So you can give a try to your file. And if it fails return to your previous file and try again. Also i think that winols needs to start a new project with an original file. So try to find an original to start with.