If the fault does come back you need to do the TC fluid. It's only 1 qt and only use BMW TC Fluid oil. Pretty straight forward easy job probably easier than an oil change actually.

What it is that it has a sensor to measure the clutch position and when the fluid shears or wears I guess it doesn't meet certain requirements so triggers a fault code.

Mine probably needs it done too at 117k but haven't gotten a code yet.