BMW bulletin B521723
BMW filed this with NHTSA as a service bulletin dated Jan 2, 2024, received Jan 3, 2024, about the seats — 2 documents under this number. It names 36 model years (2016–2024). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationCustomer states one of the front seats is inoperative. The seat heater and power supply are inoperative .During the vehicle test, the seat module does not respond. The power supply fuse for the seat module is found to have blown.
Documents filed under this number
| Document | Kind | Dated | NHTSA id |
|---|---|---|---|
| B521723 | Service bulletin | Jan 2, 2024 | 10249023 |
| B521723 | Service bulletin | Dec 11, 2023 | 10247576 |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5; the full text comes from the manufacturer or a dealer. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. Quote it at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themAlso filed against model years this site has no page for: 2020 BMW 330E; 2020 BMW 340I; 2023 BMW 340I; 2023 BMW 850I; 2021 BMW M4; 2022 BMW M4; 2023 BMW M4; 2024 BMW M4; 2023 BMW M4 GT4; 2021 BMW M440I; 2017 BMW X1 SAV.
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Common questions
Source: NHTSA, 49 CFR 579.5Is BMW B521723 a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the B521723 repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way.
Which vehicles does B521723 cover?
The manufacturer filed it against 36 model years: 2024 BMW 3 Series, 2023 BMW 3 Series, 2022 BMW 3 Series, 2021 BMW 3 Series, 2020 BMW 3 Series, 2019 BMW 3 Series and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.