[PhilipM]

Ok. I understand a little. Checksum can be seen even in the NCS.

That is a check digit, 0-9 A-Z, the VIN checksum is hex, 00-FF.

What you should do is change the VIN (long 17 digit VIN with checksum) this will be near the middle of the file. You might also see the short VIN near the bottom in the User info field (update history)

The short VIN is not used for any VIN comparison, only the full VIN.

You should also blank the milage (set to 100kms for example).
When the VIN in the dash and CAS match, the mileage will sync to the highest value, so you might see the mileage increase and then need to fix in the dash and CAS.

R270 will read the CAS eeprom and also allow you to quickly adjust CAS mileage, VIN would be done with a hex editor.

Each CAS data point has its own checksum, so you can just edit the VIN and VIN checksum, and write back to the CAS.