BMW M2 2015–2021 — technical service bulletin
Bulletin B340921 · NHTSA communication 10203335 · issued Sep 1, 2021
Technical service bulletin
communication type
Power Train
component
2015–2021
model years
18
vehicle entries
Official summary
A turbine-like noise can be heard from the rear axle while deceleration during the first 300 miles of operationwhen braking from low speed.
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.