Quote:
Originally Posted by SaNGRia
Quote:
Originally Posted by tom @ eas
241E is a factory update, the checksum would be on file with CA.
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Exactly! Thank you. |
Not exactly, because the "checksum" and what they are looking for to ascertain whether a file is factory or not are mutually exclusive.
241E is a really illogical version to flash to, particularly from the version prior to it - not going to explain why, but there is a reason why we do not elect upgrades to it. Anyone looking to take on the risk of flashing their ECU and not trust a professional to do it should really seek the previous version
Regardless, they are checking the Calibration ID and Calibration Verification Number, to match the values on record - it is a mode 9 OBD request, irrespective of the checksum. When we refer to a checksum, we are describing a value/range involved with the end result of a calculation performed by the ECU to ensure its software integrity is valid. If the checksum calculation was incorrect or not bypassed, the ECU would not function as it would be unable to verify with itself. The CVN/Cal ID are potentially related/tied into to this, depending on the software structure - but rather indirectly. Calculation of checksum/CVN also varies depending on the ECU family.
The short answer, a stock unmodified file will not have issues, whether a stock file from 2008, or the latest available one (IIRC the latest was released after 2016, and the version prior to it, 2012ish. Keep in mind there are also multiple CVNs (in this ECU, 2 are returned) so it's possible to have a "stock" calibration but fail to have the correct value if the ECU was previously tampered with/not flashed back to stock correctly.