Services · ECU file service
CVN fixing: keeping the original calibration verification number after a modification
The CVN (Calibration Verification Number) is a checksum-like value the ECU calculates over its calibration and reports over OBD. Dealer tools, inspection equipment and some manufacturer systems compare it with the value of the original software. Any change in the file — even a small one — changes the CVN.
Why it matters
- Dealer diagnostics can show that the software is not original.
- Inspection and roadside checks in some countries read the CVN over OBD.
- Fleet and lease returns where software checks are part of the inspection.
What we do in the file
- The ECU is patched so it reports the CVN of the original software.
- Checksums are corrected so the ECU runs normally.
- Can be combined with Stage 1 and other options.
Supported vehicles
VAG, BMW, Mercedes, Ford, PSA and others with Bosch EDC17/MED17/MG1/MD1 and Continental Simos/SID ECUs — send the original read to check.
How to order
Register in the AUTO-REMAP file service, upload the original read of the ECU, tick CVN fixing (warranty patch) together with any other options you need, and download the modified file — usually within minutes, complex ECUs within working hours. Checksums are corrected automatically.
Not sure your ECU is supported? Check your vehicle in the tuning catalog, look up truck and machine software in the solutions database, or write to us in any messenger.
Why Choose AUTO-REMAP.COM?
Expertise
We are market leaders in ECU modification in the world.
Quality
We use cutting-edge technologies and tools to ensure reliability.
Support
We provide consultation and technical assistance at every stage.
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