Service bulletins for the 2021 BMW 840i
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.
125 on file from NHTSA, as of 2026-10-19.
By type
By component
Only bulletins with component: Seats are shown. Show all
| B521125 | 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. |
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| B521723 | 2024-02-01. Service bulletin. ELECTRICAL SYSTEM; SEATS. 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. |
| B110321 | 2021-07-06. Service bulletin. SEATS. B58 ENGINE: ENGINE OIL FILTER REMOVAL PROCEDURE AND TOOLS . A. For the B58 engines, a BMW Oil Catch special tool for use in conjunction with removing the engine oilfilter insert is now available. |
| B520820 | 2020-11-23. Service bulletin. SEATS:FRONT ASSEMBLY:HEAD RESTRAINT. CC MESSAGE "FAILURE OF HEAD RESTRAINT ADJUSTMENT ON PASSENGER'S SIDE": Customer states he/she has received a sporadic Check Control message (CCM) "Failure of head restraint adjustment on passenger's side". This is CCM ID-2184. This message appears when the customer folds down the front passenger seat and drives off. The front passenger seat is unoccupied. The CCM (ID-2184)- Appears after 60 seconds States that the head restraint is faulty and that the customer could injure themselves Recommends visiting a workshop Software in the seat module. |
| B520720 | 2020-11-23. Service bulletin. SEATS. SEAT HEATING NOT ACTIVATED WHEN ENGINE IS STARTED USING REMOTE STARTING SYSTEM: When preheating/precooling the vehicle via the remote starting system (Remote Engine Start), the seat heating on the driver's side is not activated. |
| B520820 | 2020-11-16. Service bulletin. ELECTRICAL SYSTEM; SEATS:FRONT ASSEMBLY:HEAD RESTRAINT. CC MESSAGE "FAILURE OF HEAD RESTRAINT ADJUSTMENT ON PASSENGER'S SIDE": Customer states he/she has received a sporadic Check Control message (CCM) "Failure of head restraint adjustment on passenger's side". This is CCM ID-2184. This message appears when the customer folds down the front passenger seat and drives off. The front passenger seat is unoccupied. The CCM (ID-2184)- Appears after 60 seconds States that the head restraint is faulty and that the customer could injure themselves Recommends visiting a workshop Software in the seat module. |
| B520720 | 2020-11-16. Service bulletin. SEATS:FRONT ASSEMBLY:SEAT HEATER/COOLER. SEAT HEATING NOT ACTIVATED WHEN ENGINE IS STARTED USING REMOTE STARTING SYSTEM: When preheating/precooling the vehicle via the remote starting system (Remote Engine Start), the seat heating on the driver's side is not activated. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.