# Service bulletin B521723

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: 10249023
- Published by NHTSA: 2024\-02\-01
- Manufacturer's number: B521723
- Manufacturer's date: 2024\-01\-02
- NHTSA component: ELECTRICAL SYSTEM; SEATS

## NHTSA's summary

Customer 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 isfound to have blown.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2024/MC-10249023-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2024/MC-10249023-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system, Seats

## Vehicles listed

- 2023 BMW 3 SERIES
- 2023 BMW 3 SERIES
- 2023 BMW 3 SERIES
- 2023 BMW 3 SERIES
- 2020 BMW 330E
- 2021 to 2024 BMW 330E
- 2019 to 2024 BMW 330I
- 2019 BMW 340I
- 2020 BMW 340I
- 2023 BMW 340I
- 2023 BMW 4 SERIES
- 2020 to 2024 BMW 430I
- 2020 BMW 440I
- 2023 BMW 8 SERIES
- 2020 to 2024 BMW 840I
- 2023 BMW 850I
- 2021 to 2024 BMW M4
- 2023 BMW M4 GT4
- 2021 to 2024 BMW M440I
- 2017 to 2022 BMW X1
- 2017 BMW X1 SAV

## Recalls for the same vehicles and component

- [26V056000](/recalls/nhtsa/26V056000.md), 2026-01-30: ELECTRICAL SYSTEM:STARTER ASSEMBLY
- [25V644000](/recalls/nhtsa/25V644000.md), 2025-09-25: ELECTRICAL SYSTEM:STARTER ASSEMBLY
- [2025499](/recalls/tc/2025499.md), 2025-09-23: Electrical
- [25V636000](/recalls/nhtsa/25V636000.md), 2025-09-23: ELECTRICAL SYSTEM:STARTER ASSEMBLY:RELAY
- [2024444](/recalls/tc/2024444.md), 2024-08-01: Electrical
- [24V576000](/recalls/nhtsa/24V576000.md), 2024-08-01: ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE \(ECU/ECM\):SOFTWARE; ELECTRICAL SYSTEM:STARTER ASSEMBLY
- [23V584000](/recalls/nhtsa/23V584000.md), 2023-08-16: ELECTRICAL SYSTEM:SOFTWARE; SEAT BELTS
- [23V211000](/recalls/nhtsa/23V211000.md), 2023-03-29: SEATS
- [2023093](/recalls/tc/2023093.md), 2023-02-24: Electrical
- [23V118000](/recalls/nhtsa/23V118000.md), 2023-02-23: ELECTRICAL SYSTEM:BODY CONTROL MODULE:SOFTWARE

## Other bulletins for the same vehicles and component

- [B110426](/bulletins/11035500.md), 2026-08-03, Service bulletin: ENGINE; ELECTRICAL SYSTEM. The manual starting of electronic engine oil level measurement from inside the vehicle, usually afterperforming an engine oil service task, is inoperative or it may lock up at between a 15% to 30% completionrate.
- [B840226](/bulletins/11035408.md), 2026-07-31, Service campaign: ELECTRICAL SYSTEM. Once the Telematics Module \(TCB2\) enters sleep mode, a BMW Data Services trigger for Remote Services\(remote engine start, lock/unlock/climate conditioning\) will not be able to reactivate the TCB2. Due to this issue, Remote Services will not function in the vehicle when parked and locked.
- [B652026](/bulletins/11035404.md), 2026-07-31, Service bulletin: ELECTRICAL SYSTEM. The Central Information Display \(CID\) side of the Multifunction Display \(MFD\) may flicker intermittently. Theflickering manifests itself in three phases: The image is distorted The central information display turns black \(black screen\) The image is OK again The complete flickering episode with all the above\-mentioned three phases only lasts about half a second intotal each time.
- [B652025](/bulletins/11032744.md), 2026-05-18, Service bulletin: ELECTRICAL SYSTEM. After replacing the Multifunctional Display \(MFD\), the Central Information Display \(CID\) is black. The backlight of the CID is illuminated, and touch function does register an audible sound.
- [B062026](/bulletins/11029021.md), 2026-02-25, Other: ELECTRICAL SYSTEM. KLE Control Unit Return
- [B641325](/bulletins/11026960.md), 2026-01-05, Service bulletin: ELECTRICAL SYSTEM. When performing a vehicle test, diagnostic trouble code “ 8013FE Software run time error” is found in theIHKA module. If this fault is set for two consecutive life cycles, it will turn on the check engine light on vehicles with an I\-level lower than 24\-11\-570. This fault memory entry does not cause an impairment of functionality of the automatic air conditioningsystem.
- [B840625](/bulletins/11024211.md), 2025-10-09, Service bulletin: ELECTRICAL SYSTEM. In some situations, an emergency call may be triggered in the vehicle without either the customer pressing the SOS Call button, or an airbag deployment event. In some cases, the customer may not even be inside the vehicle.
- [B840525](/bulletins/11022119.md), 2025-08-24, Service bulletin: ELECTRICAL SYSTEM. SITUATION After the telematics module \(TCB4\) has been replaced, the replacement part control unit is not accepted byISTA.
- [B521125](/bulletins/11022110.md), 2025-08-24, Service bulletin: SEATS; ELECTRICAL SYSTEM. If the seat ventilation is deactivated via the switch or due to parking the vehicle, the fans in the seat cushionor under the seat cushion surface are unpleasantly loud. The fans speed up loudly twice and then turn off. The functionality of the fans is not impaired. This behavior only occurs after the vehicle had been programmed to I level S18A\- 25\-07\-520 and higher; upto, but not including S18A\- 25\-07\-551.
- [B651825](/bulletins/11021819.md), 2025-08-13, Service bulletin: ELECTRICAL SYSTEM. When the alarm system is activated and doors are locked, within a short period the doors will unlock, and a “double beep” acoustic confirmation is heard from vehicle.

JSON: [/v1/bulletins/10249023](/v1/bulletins/10249023)

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