I believe that's the code for the "recommended gear indicator", not the "current gear indicator", at least on the OG M2. I can poke around in E-Sys later today to check for sure. EDIT: no, it's the current gear indicator, but doesn't seem like it works on 6MT.
This thread seems to have some additional thoughts, though it doesn't look good:
https://www.bimmerfest.com/forums/sh...d.php?t=860456 (seems like MT is in a weird place in that it might not know what gear we're in, and instead suggests what it thinks it should be based on speed and engine RPM).
EDIT:
https://f87.bimmerpost.com/forums/sh....php?t=1547942 seems to indicate that MT doesn't work :/