031781 خطایی است که در حافظهی BMW شما ذخیره شده است (کد خطای ISTA، نه کد استاندارد P از نوع OBD-II).
یعنی چه: Head unit (HU-H) — Real-Time Traffic Information (RTTI) functionally limited. This is NOT a faulty part: it's an ambient/back-end issue (temporary loss of the traffic-data connection or a back-end restriction). Replacing components won't help — it clears itself once the service/connection is back. Informational, nothing to worry about.