Unlocking ECU for variant coding?




Google says the ECU needs to be unlocked first - how to unlock it on W221? Others say that the coding values need to be in a plausible combination - does it make sense? Thanks!




My recent posts have been about my new-found "skill" of updating programming, which I have, by and large, not done. Discretion being the better part of cards...
Looks like George and I have similar S600's. My version currently looks like this:
It's running, I think, Oct 2007 software done by the dealer in Mar 2008. I have, again-- I think, newer software but don't know if an update would be useful... Especially, if I can't do it w/o Variant coding!!!
Regards... Mark




Also my ECU Version shows: "UNKNOWN_VARIANT" and DAS complains about it. Was S400 ECU ever programmed at the factory with "UNKNOWN_VARIANT" or does it look like someone has been here before messing up stuff?
Last edited by George993; Mar 6, 2021 at 11:19 AM.



