Thanks to NiVeDh:
This feature is for 6MT cars only. It basically tells you when to upshift and downshift and to which gear for maximum fuel efficiency.
It normally suggests upshifts at very low RPMs (~2000). It works well.
Once coded, it can be enabled/disabled through the OBC by pressing the BC button the indicator stalk until the instrument cluster goes to the blank screen (not displaying anything such as mpg, range, etc.). Once there, holding down the BC button for around 5 seconds toggles the feature on or off.
Here's a video:
Here's what to code...
SP_ANZEIGE -> aktiv
SCHALT_PKT_BC -> aktiv