MED17.5 CVN — checksum recalculation: VAG (Audi · Seat · Skoda · VW)
Auto-fix of the CVN and checksums for the MED17.5 block (TriCore TC1766) — after Stage 1, Stage 2, DPF off, EGR off and any calibration edits.
Auto-fix of the CVN and checksums for the MED17.5 block (TriCore TC1766) — after Stage 1, Stage 2, DPF off, EGR off and any calibration edits.
Upload the original and modified firmware — the tool shows the CVN for free. Applying the fix — in the portal.
FULL dump of the firmware — via bench, boot mode or OBD full read.
Virtual OBD dumps and MAPS exports — they have no CVN service sections.
The MED17.5 block (TriCore TC1766) is fitted to petrol vehicles Audi, Seat, Skoda, Volkswagen — 246 modifications in total. After any calibration edits — Stage 1, Stage 2, EGR, DPF, SCR (AdBlue) off, immo-off — the CVN value changes, and the ECU may throw mismatch errors or refuse to accept the firmware.
The CVN (Calibration Verification Number) is a checksum of the calibration data block that the ECU verifies at every start and on a scanner request via OBD-II Mode $09. The tool recalculates the CVN for the modified firmware: upload the file, get the correct value — in a second and for free.