# Service bulletin B121125

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: 11022357
- Published by NHTSA: 2025\-09\-03
- Manufacturer's number: B121125
- Manufacturer's date: 2025\-08\-26
- NHTSA component: ENGINE; ELECTRICAL SYSTEM

## NHTSA's summary

A 740i Sedan, 740i xDrive Sedan \(B58N \- ICEV\), or a 750e xDrive Sedan \(XB1N \- PHEV\) may have one orboth of the following faults stored in the DME: 034AA5 \- Mixture control bank 1, lambda regulation, mixture too lean 034AA8 \- Mixture control bank 1, lambda adaptation, mixture too rich And additionally with the faults above, these affected vehicles may have one or more of the followingirregular combustion\-related faults also stored: 033812 033813 033814 033815 033816 033817 033818 033819

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11022357-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11022357-9999.pdf)

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

## Components

Electrical system, Engine

## Vehicles listed

- 2025 BMW 740I

## Other bulletins for the same vehicles and component

- [B110326](/bulletins/11036376.md), 2026-08-26, Service bulletin: ENGINE. This Service Bulletin provides instructions to clean the intake valves using the BMW Carbon Blaster Tool P/N 81 29 2 208 034 and the S68T / XB1T Kit P/N 83 30 5 BAD 3D5. Refer to SI B04 12 11 for existing documentation about the carbon blaster tool and SI B04 02 26 for the S68T /XB1T tool kit.
- [B170126](/bulletins/11035398.md), 2026-07-31, Service campaign: ENGINE. The coolant vent lines of the low\-temperature circuit are designed to remove air bubbles from the system toensure optimal cooling performance. Internal quality inspections have revealed that leaks may occur due tolocalized material aging on the vent lines. These leaks occur because the material originally used is notsufficiently resistant to the continuously high temperatures. A coolant leak may result and cause a yellow check control message and reduced engine performance.
- [B120326](/bulletins/11035396.md), 2026-07-31, Emissions: ENGINE. Due to an implementation error in various OBD diagnostics in the vehicle's control units, in very rare cases itmay happen that stored fault memory codes \(DTCs\) and the MIL \(warning light\) are not automaticallydeleted even though the underlying malfunction has already been rectified. This does not comply with the statutory OBD specifications.
- [B110326](/bulletins/11035392.md), 2026-07-31, Service bulletin: ENGINE. This Service Bulletin provides instructions to clean the intake valves using the BMW Carbon Blaster Tool
- [B651426](/bulletins/11034467.md), 2026-07-03, Service bulletin: ELECTRICAL SYSTEM. The vehicle may experience various operational issues with Apple CarPlay Projected Modes such as: Dropped connections No automatic reconnection Display errors
- [B610126](/bulletins/11034462.md), 2026-07-03, Service bulletin: ELECTRICAL SYSTEM. During vehicle start\-up the Secure Element \(SE\) of the BCP may fail causing communication errors. TheCheck Control message “Drive carefully. Driving stabilisation.” will appear. In addition, the fault memoryentries below will be stored within 40 seconds of each other. ACSM: 02010A \- Coding: Coding data not qualified VIP: 02390A \- VIP control unit: Coding data not released, signature IB: 02290A \- DSC control unit: Coding data not released, signature HKFM: 020D0A \- HKFM: Coding data are not qualified
- [B650826](/bulletins/11030312.md), 2026-03-30, Service bulletin: ELECTRICAL SYSTEM. After the software update to version …25\-07\-5XX, existing activation points for the “Automate My Habits”function no longer work.
- [B120326](/bulletins/11030305.md), 2026-03-30, Emissions: UNKNOWN OR OTHER; ENGINE. PROGRAM CONTROL UNITS \(OBD\)
- [B120326](/bulletins/11030061.md), 2026-03-13, Emissions: ELECTRICAL SYSTEM. BMW AG is conducting Voluntary Emissions Recall \(effective March 11, 2026\) on certain Model Year 2023 \-2026 BMW vehicles that were produced between January 14, 2022, and September 16, 2025.
- [B610126](/bulletins/11029070.md), 2026-02-27, Service bulletin: ELECTRICAL SYSTEM. During vehicle start\-up the Secure Element \(SE\) of the BCP may fail causing communication errors. TheCheck Control message “Drive carefully. Driving stabilisation.” will appear. In addition, the fault memoryentries below will be stored within 40 seconds of each other. ACSM: 02010A \- Coding: Coding data not qualified VIP: 02390A \- VIP control unit: Coding data not released, signature IB: 02290A \- DSC control unit: Coding data not released, signature HKFM: 020D0A \- HKFM: Coding data are not qualified

JSON: [/v1/bulletins/11022357](/v1/bulletins/11022357)

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