OBD2 Mode 9 Calibration ID and Numbers Vehicle Identification Number (VIN) Module Calibration Number (CALID) Calibration Verification Number (CVN) In-use Performance Ratio (IUPR) values The VIN is a unique number which identifies the vehicle It’s defined by an international standard and every vehicle in use has an unique VIN
Is the Calibration Verification Number (CVN) unique The CVN is not unique across all cars, at least this is my understanding As spelled out from this forum post: CVN stands for "Calibration Verification Number", this is a fancy name for checksum What the ECM (or TCM) does is add up all the numbers within each segment of the flash memory, the total of those numbers is what the CVN equals This allows people with a TechII to quicky check the