I asked my dealer to code ASS to last mode, before I first picked up my 335i, and they did.
A few weeks later I tried to use my HVAC heating and it didn't work.
Finally after a couple of trips to the shop they had to reprogram the system.
The explanation was that, when they coded the ASS that somehow interfered with the HVAC programming.
I tend to believe that because German electrical/electronic systems have always been tied together in weird ways.
In 1988 I bought a used 1982 Audi 5000S Turbo. One day I turned on the windshield wipers and all of sudden the radio started going in and out according to the beat of the wipers!
I was like WTF is this?! Quick check and a fuse for the wipers was blown, replaced it an all was well.
BUT, how do the wipers keep working when the fuse is blown?
I guess it takes some power away from the audio system so that it can keep working.
Those crazy Germans.