So here is a little tutorial by – how to make checksums for ecu files with Winols tuning software, that should help all of you who don’t know how to do this get started using Winols.

Checksums are very important, get them wrong and car won‘t start or even worse

1.If you haven’t installed Winols 2.24 first, then do so, it can be found here on CT using the search button, this is not the search box

2.Open Winols, and after you will see the empty working box, picture 1A. Now drag and drop your ecu file onto this box as in picture 1B. Now in picture 1, you can see there are 3 checksums that need correcting, Winols will do this for you.

3.Follow the instructions in following pictures and this should get you started making checksum for your own files.

Run Winols

Drag petio 3,.0 asn_lambda_off_nochecks.bin into Winols

You will see the pop-up: 3 checksum(s) not correct

Correct the original data file

Map search in progress

All CS ok -Checksum block 5: okay

Project->Ex-&Import->Export file…

Enter info

Select Binary file

Save as petio 3,.0 asn_lambda_off_nochecks_csok.bin

All CS ok -Checksum block 5: okay

In summary, how to checksum correcting by Winols chip tuning software:

1.First, drag and drop the original untouched file into Winols in the same way as in the pictures. When it has finished loading the original
file …then can now drag and drop your modified file ontop of the original file you already loaded into Winols.
3.Now you can follow the checksum procedure steps exactly as described in the pictures, correcting modfile checksums.


Q: I found a stage1 tuning file and while I was inserting it into Winols it says me: “This software version cannot be processed, since it is already modified” Could somebody please help me what does it mean?

A: Open the file in a simple hex editor, click search txt string NOREAD
when you find the words “noread” write over them with FFFFFF, save changes and try again with Winols

Q: If I read and write files with Kess V2 or KTag clone did they make checksum correction or must be done with Winols?

A: With those tools checksum will be done in writing