BMW 428I 2014–2018 — technical service bulletin
Bulletin B540218 · NHTSA communication 10135038 · issued Feb 1, 2018
Technical service bulletin
communication type
Structure
component
2014–2018
model years
14
vehicle entries
Official summary
NOISES FROM THE C-PILLAR AREA OF THE CONVERTIBLE TOP: Cracking or clicking noises can be heard from the rear area of the convertible top (C-pillar area) when driving on uneven roads.
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.