BMW 330E 2019–2021 — technical service bulletin
Bulletin B340320 · NHTSA communication 10177623 · issued Jun 1, 2020
Technical service bulletin
communication type
Service Brakes, Hydraulic
component
2019–2021
model years
6
vehicle entries
Official summary
PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH STANDARD BRAKES: The CBS data and Check Control (CC) message shows the rear axle brake pads are worn, and the vehicle has less than 15,500 miles. Increased residual braking forces in the rear axle brake calipers caused by production-related deviations on the surface of the piston ring seal.
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.