BMW bulletin B520424
What it saysThe following fault memory entries in the BCP_01 are displayed in the vehicle’s fault memory withoutjustification: 804344 – Control electronics, front active seat ventilation, driver's seat cushion (LIN):Communication… NHTSA’s full summary ↓
BMW filed this with NHTSA as a service bulletin dated May 31, 2024, received Jun 1, 2024, about the electrical system. It names 1 model year (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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThe following fault memory entries in the BCP_01 are displayed in the vehicle’s fault memory withoutjustification: 804344 – Control electronics, front active seat ventilation, driver's seat cushion (LIN):Communication fault detected 804345 – Control electronics, front active seat ventilation, seat cushion of front passenger (LIN):Communication fault detected
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| B520424 | Service bulletin | May 31, 2024 | 11000614 | PDF, 87 KB |
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.
Model years it names
Source: as the manufacturer filed themA 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 1 model year this bulletin names have filed 8 complaints with NHTSA since 2015. 1 of them name Electrical System — 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 contact owns a 2024 BMW 750E. The contact stated while driving at an undisclosed speed, the high-voltage system warning light illuminated. The contact continued to drive the vehicle a short distance, and then the drive train warning light illuminated.
2024 BMW 7 Series · Electrical System · filed with NHTSA Nov 13, 2025 · ODI 11699171
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 electrical system
Source: same model, same component group77 other manufacturer communications filed against the BMW 7 Series under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the BMW list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| B611826 | Service bulletin | Sep 17, 2026 | Due to unfavorable software, the Storage Management Electronics (SME) will not show fault codes that trigger the Malfunction Indicator Lamp… |
| B630526 | Service bulletin | Sep 8, 2026 | After programming the vehicle via ISTA/RSUto I-level …26-03-5xx, customer may reportsome of the interior ambient lighting strips(arrows) may… |
| 0034040300 | Service campaign | Aug 20, 2026 | After replacement of the Integrated Braking system (IB)/Power Brake the total distance covered might be lower than when handed over to the w… |
| B652026 | Service bulletin | Jul 23, 2026 | The Central Information Display (CID) side of the Multifunction Display (MFD) may flicker intermittently. Theflickering manifests itself in… |
| B840226 | Service campaign | Jul 10, 2026 | Once the Telematics Module (TCB2) enters sleep mode, a BMW Data Services trigger for Remote Services… |
| B610126 | Service bulletin | Jun 11, 2026 | SITUATION During vehicle start-up the Secure Element (SE) of the BCP may fail causing communication errors. TheCheck Control message “Drive… |
| B651426 | Service bulletin | Jun 4, 2026 | The vehicle may experience various operational issues with Apple CarPlay Projected Modes such as: Dropped connections No automatic reconnect… |
| B652025 | Service bulletin | May 5, 2026 | After replacing the Multifunctional Display (MFD), the Central Information Display (CID) is black. The backlight of the CID is illuminated… |
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 B520424 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 B520424 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 B520424 cover?
The manufacturer filed it against 1 model year: 2024 BMW 7 Series. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.