Service bulletin B340921
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
| Type | Service bulletin |
|---|---|
| NHTSA id | 11013041 |
| Published by NHTSA | 2025-01-23 |
| Manufacturer's number | B340921 |
| Manufacturer's date | 2025-01-14 |
| NHTSA component | SERVICE BRAKES |
NHTSA's summary
A turbine-like noise can be heard from the rear axle while deceleration during the first 300 miles of operation when braking from low speed.
The document
The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.
Components
Brakes
| BMW M3 | 2016, 2017, 2018 |
|---|---|
| BMW M4 | 2016, 2017, 2018, 2019, 2020 |
| BMW M5 | 2016 |
| BMW M5 | 2018, 2019, 2020 |
Listing a model year does not mean every vehicle of it is concerned: the document says which.
| B064725 | 2025-10-10. Other. Protection Plate Return |
|---|---|
| B340714 | 2023-11-01. Service bulletin. Functional noises (squealing/honking) when braking shortly before the vehicle comes to a stop. CAUSE Material- |
| B340921 | 2023-03-20. Service bulletin. A turbine-like noise can be heard from the rear axle while deceleration during the first 300 miles of operation when braking from low speed. |
| B341019 | 2021-11-08. Service bulletin. Inform the customer during a consultation that the M Compound (standard equipment) and M Carbon Ceramic (optional) brakes are high-performance brake systems which are designed for sporty, dynamic driving styles. As a side effect of the highest possible brake performance, customers are likely to hear noises due to the extremely resilient materials. In the same conversation, inform the customer that his/her braking performance can help ensure that the noises do not occur or disappear quickly. |
| B341019 | 2021-09-07. Service bulletin. Inform the customer during a consultation that the M Compound (standard equipment) and M Carbon Ceramic (optional) brakes are high-performance brake systems which are designed for sporty, dynamic driving styles. As a side effect of the highest possible brake performance, customers are likely to hear noises due to the extremely resilient materials In the same conversation, inform the customer that his/her braking performance can help ensure that the noises do not occur or disappear quickly. |
| B360121 | 2021-05-24. Service bulletin. Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal stresses during rapid heating and cooling of the brake discs. Braking from high speed with cold brake components (less than 212 degrees F) increases the likelihood of cracks to form. |
| B340414 | 2021-05-24. Service bulletin. Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal stresses during rapid heating and cooling of the brake discs. Braking from high speed with cold brake components (less than 212 degrees F) increases the likelihood of cracks to form. |
| B510221 | 2021-04-26. Service bulletin. AIR DUCT COVER LOOSE OR MISSING: The air duct cover (fender mounted) may be loose or missing. Prolonged high-speed driving can cause movements of the fender, causing the air duct to become loose. |
| B340517 | 2020-08-31. Service bulletin. TICKING NOISE WHILE CORNERING WITHOUT THE BRAKES APPLIED: Ticking noise coming from front wheel while cornering without brakes applied, noticeable at low speeds. The vehicle must be moving. |
| B513016 | 2020-04-20. Service bulletin. TAILGATE UNINTENTIONALLY OPENS: This Service Information Bulletin (Revision 4) replaces SI B51 30 16 dated March 2018. Trunk/tailgate may open when vehicle is locked Trunk/tailgate may open while the vehicle is in motion usually after stopping such as a traffic light etc. Vehicle key trunk/tailgate button may be accidentally pressed thus opening the tailgate. |