Originally Posted by skierman64
Can someone translate this to english. Does that mean I'll be able to change to the new Idrive controller or not.
It means simply that your car is production 03/08 so it still has the "old" CDMA TCU for the Assist system. What that relates to the OP problem is anybody's guess.
We know for sure that the -048 and the -309 replacement iDrive controllers work in a 05/08 production M3, based on mine and in another member retrofit. We know that the -048 controller is the P/N of both the M3 Sedan and the MY2009 5-Series, and that the M3Coupe and Convertible controller has a different P/N ending in -050, however the -048 controller is already known to work in a M3 Coupe so that eliminates any compatibility issues between the Sedan and the Coupe/Convertible controllers based on P/N. We know that the -048 controller was effective from production 09/08 up to 02/09, and the -309 controller is effective from 03/09 -on. If you ordered a -048 controller after 02/09 you will automatically get a -309 controller. So there is a difference in controllers based on production date and not on body style, at least in P/N. That is different from the -048 and the -050 split.
What we do not
know is what happened with the OP 01/08 production iDrive and the -309 controller that they don't like each other. We know that there was at least a TCU hardware/software change in 04/08 production M3, that may or may not
affect this new -309 controller functionality with the "old" iDrive; this is just a guess.
It could be as simple as an iDrive update that the OP M3 have not received and the 05/08 production has, or it could be as simple as that particular controller is defective. We do not know.
I will be testing my controller in a 04/08 M3 soon, so that could help a little to verify compatibility depending of production date or iDrive coding version.