BMW bulletin B540521
What it saysThe sunroof will not operate in either direction. NHTSA’s full summary ↓
BMW filed this with NHTSA as a service bulletin dated Aug 1, 2023, received Dec 20, 2021, about the visibility/wiper — 3 documents under this number. It names 37 model years (2016–2023). 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThe sunroof will not operate in either direction. There are NO faults stored related to the sunroof. If the vehicle has any faults stored related to the sunroof, this bulletin does not apply.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| B540521 | Service bulletin | Aug 1, 2023 | 10242698 | not found |
| B540521 | Service bulletin | Nov 1, 2022 | 10228433 | not found |
| B540521 | Service bulletin | Nov 1, 2021 | 10205091 | not found |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. 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. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
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Model years it names
Source: as the manufacturer filed themAlso filed against model years this site has no page for: 2019 BMW 540D; 2020 BMW 540D; 2018 BMW B7 Alpina; 2019 BMW B7 Alpina; 2020 BMW B7 Alpina; 2021 BMW B7 Alpina; 2018 BMW C 400 X; 2021 BMW F 850 GS Adventure; 2017 BMW F800 R; 2021 BMW M760LI; 2022 BMW M760LI.
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 26 model years this bulletin names have filed 534 complaints with NHTSA since 2015. 6 of them name Structure, Visibility/Wiper — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
The car was purchased new in July 2023. On or about , while the car was parked the front license plate holder separated suddenly and unexpectedly from the front bumper of the car and fell to the ground. Incidental to the failure of the front license plate holder, the separation of the holder caused damage to the front bumper.
2023 BMW 5 Series · Structure · filed with NHTSA Apr 29, 2024 · ODI 11585838
Not really sure if this would be considered a safety complaint, but it could lead to problems if not corrected. The upper radiator shuttle will not function properly. This can cause restricted climate control in the vehicle interior, reduction of engine performance and possibly engine overheating.
2016 BMW 7 Series · Structure · filed with NHTSA Nov 8, 2020 · ODI 11373643
Company is selling reflector inserts that are not legal. The removal of safety device(s) is suspect at this time. The part removes the reflective safety feature and replaces with a dull black insert preventing reflection of said vehicle rendering a possible safety hazard. I do not use the product.
2022 BMW M · Visibility/Wiper · filed with NHTSA Sep 29, 2022 · ODI 11487053
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the visibility/wiper
Source: same model, same component group11 other manufacturer communications filed against these BMW models under the same component group (visibility/wiper), newest first. The eight newest are listed; the rest are on the BMW list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| B610526 | Service bulletin | Mar 20, 2026 | Customers might report that washer fluid is leaking from the lower reservoir area, especially around thewasher fluid pumps. |
| B511924 | Service bulletin | Jan 22, 2026 | There is a matte “veil” or milky stain on theexterior mirror glass. Passenger side mirror shown; situation canoccur on either or both exteri… |
| B630224 | Service bulletin | Aug 21, 2024 | After programming the vehicle or completing aBMW RSU (Remote Software Upgrade), theblue accents (arrows) of both headlights arenot functioni… |
| B510923 | Service bulletin | Aug 19, 2024 | Sudden failure of the power window(s). |
| B540319 | Service bulletin | Aug 14, 2024 | GROANING NOISE FROM SUNROOF . A groaning noise is present from the area between the front and rear sunroof glass panels only with the sunroo… |
| B660424 | Service bulletin | Jul 16, 2024 | The washer fluid cleaning system has air remaining in its components, and/or the fluid lines after a previous repair has been performed. The… |
| B640422 | Service bulletin | Feb 16, 2024 | An interference noise (groaning noise) can be heard from within the heating and air-conditioning unit in thecenter of the instrument panel.… |
| B612823 | Service bulletin | Nov 9, 2023 | A thumping sound is heard when the window reaches the closing end stop. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for BMW, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is BMW B540521 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 B540521 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. Every BMW warranty extension on file lists the ones BMW has filed.
Which vehicles does B540521 cover?
The manufacturer filed it against 37 model years: 2023 BMW 5 Series, 2022 BMW 5 Series, 2021 BMW 5 Series, 2020 BMW 5 Series, 2019 BMW 5 Series, 2018 BMW 5 Series and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.