BMW 330E 2019–2021 — technical service bulletin
Bulletin B540120 · NHTSA communication 10179002 · issued Jul 1, 2020
Technical service bulletin
communication type
Structure
component
2019–2021
model years
4
vehicle entries
Official summary
SERVICE ACTION - CHECK SUNROOF SEALING: The sunroof frame may not have been properly sealed, causing a water leak into the vehicle. Improper sealing during production.
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.