D0189B is a fault stored in your BMW's memory (an ISTA fault code, not a standard OBD-II P-code).
What it means: The chassis module ICM is not receiving the steering-wheel vibration message for the lane departure warning from the KAFAS camera — the vibration warning will not work. Check the camera by the mirror, its power supply and wiring; the vibration unit in the steering wheel itself may also be faulty.
