12V message in IC when starting the vehicle.
SW updates need to be performed.
Follow the guided test for FC U116000 in N73/3*1 EIS CU.
Perform the SW checks and updates.
Fully charge both 12V and 48V batteries.
After, perform a few drive/park cycles with at least 1 overnight park cycle.
If the 12V message is no longer present, release the vehicle.