BMW 640I 2012–2017 — technical service bulletin
Bulletin B520819 · NHTSA communication 10163044 · issued Jun 1, 2019
Technical service bulletin
communication type
Seats
component
2012–2017
model years
17
vehicle entries
Official summary
Front seat backrest makes a cracking noise when folded forward.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.