I had an issue with my shifter, 09 35d, not allowing the shifter to be moved into sport mode. I also had a code for a shifter malfunction when checking codes with DIS. I do not remember the exact code.
Taking the shifter out is very easy, you can then remove the 4 or 5 screws holding the top part of the shifter to the bottom part. It is spring loaded so hold pressure down on the upper section to slowly release the pressure with the screws. In the bottom cavity of the shifter assembly you will find a white piece of plastic that is moved by a cam actuated by a small motor. apparently my motor went out and left the plastic extended causing the shift lever to not go into sport mode. I simply removed this instead of buying a new shifter assembly and have not had an issue.
Your problem my be similar if the motor is stuck in a different position.