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November 12, 2025 Service bulletin

One or both of the following faults stored in the DME: 034AA5

BMW technical service bulletin B121125 for 2024-2025 BMW 530I and 2024-2025 BMW 740I.

Bulletin number
B121125
Component
Engine
Summary
One or both 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

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