Even with a plugin installed, you may occasionally encounter errors. Here is how to resolve the most common issues:

Used in VAG, BMW, and Mercedes gasoline engines. These ECUs use a complex "Checksum + RSA" pairing. A standard plugin will fix the checksum but not the RSA signature. Ensure your plugin actually says "MED17 Full Checksum."

The internet is littered with broken links and malicious downloads. Below are the safest and most reliable sources for your checksum plugin download.

You downloaded the file, installed it, but WinOLS doesn't see it. Here is the fix.