Originally Posted by cds72911

Solved - @Best4x4 had it right. I didn't realize that there are two places where transmission type is set - the one that I was looking at before is under "TRANS-LOCK-WARN" and was set to AUTO, the other one is under "INSTRUMENT PACK" and this was set to MANUAL.

The configuration switch in the INSTRUMENT PACK is labeled "TRANSMISSION" and the options are MANUAL and AUTO.

Somehow (no doubt through my fat fingering it while mucking around) that had been set to MANUAL.

Once I set it to AUTO and saved the settings to the BCU, everything was back to normal - the gear indicator now shows up on the dash display, and the Sport Mode button works (lights up a green gear/S light on the dash when engaged).

Thanks for the guidance everyone. I wouldn't have been able to solve this without you.