Service bulletins for the 2021 BMW X4
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.
168 on file from NHTSA, as of 2026-10-19.
By type
By component
Only bulletins with component: Heating and air conditioning are shown. Show all
| B640422 | 2024-03-02. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. An interference noise (groaning noise) can be heard from within the heating and air-conditioning unit in thecenter of the instrument panel. The groaning noise always occurs when either a ventilation flap, air stratification flap or the recirculated airflap moves to a different position. Due to the complex design of the heating and air-conditioning unit, the kinematics causing it (top or bottom,left or right) may not be able to be precisely located. Depending on the vehicle model, the number of servomotors (and the associated kinematics unit) varies.Various models use either 2 or 3 servomotors. |
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| B640422 | 2022-10-31. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. An interference noise (groaning noise) can be heard from within the heating and air-conditioning unit in the center of the instrument panel. |
| B640321 | 2021-12-20. Service bulletin. EQUIPMENT; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. After replacing the microfilter during a previous service, the customer notices that the ventilation system airflow rate is noticeably less. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.