Originally Posted by Roman@ESS
231E is backwards compatable with older module software. If you want to update older module software at the dealer you can but it is not required to update the ECU to 231E.
Right, but remember that the system the dealership uses will throw errors if you try to update it and the modules don't match. I know that updating the light control module on my old 335i made the dealership's computer barf when they tried to update. (I had to replace it with a friend's unit that had the original software on it)
I don't know what happens when the module is older than the main DME software, but I do know that it can barf when the module is newer. Not trying to throw you guys under the bus, but the other tuners usually don't update the DME software without updating the modules, just curious if you guys are doing something special or if the customer will have issues if they try to get their software updated.