# Service bulletin B640321

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: 10205096
- Published by NHTSA: 2021\-12\-20
- Manufacturer's number: B640321
- Manufacturer's date: 2021\-11\-01
- NHTSA component: EQUIPMENT; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM

## NHTSA's summary

After replacing the microfilter during a previous service, the customer notices that the ventilation system airflow rate is noticeably less.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10205096-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10205096-9999.pdf)

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

## Components

Equipment and accessories, Glass, wipers and mirrors, Heating and air conditioning

## Vehicles listed

- 2021 BMW 330E
- 2019 to 2021 BMW 330I
- 2020 to 2021 BMW M340I
- 2018 to 2021 BMW X3
- 2019 to 2021 BMW X4
- 2019 to 2021 BMW Z4

## Recalls for the same vehicles and component

- [2021078](/recalls/tc/2021078.md), 2021-02-18: Visual System
- [2019480](/recalls/tc/2019480.md), 2019-10-01: Visual System

## Other bulletins for the same vehicles and component

- [B630418](/bulletins/11020927.md), 2025-07-28, Service bulletin: VISIBILITY/WIPER. One or more of the LED daytime running lights are dim or discolored.
- [B660720](/bulletins/10250601.md), 2024-03-02, Service bulletin: EQUIPMENT; ELECTRICAL SYSTEM. The functionality of the left rear SRR sensor could be reduced which would display the Driving Assistance Check Control Message.
- [B660820](/bulletins/10250600.md), 2024-03-02, Service bulletin: ELECTRICAL SYSTEM; EQUIPMENT. The functionality of the right rear SRR sensor could be reduced which would display the "Driving Assistance"\- Check Control Message.
- [B640422](/bulletins/10250374.md), 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.
- [B510819](/bulletins/10249437.md), 2024-02-01, Service bulletin: VISIBILITY:POWER WINDOW DEVICES AND CONTROLS; ELECTRICAL SYSTEM. The basic conditions for initializing the power windows are not met.
- [B610524](/bulletins/10249032.md), 2024-02-01, Service bulletin: EQUIPMENT:ELECTRICAL:INFOTAINMENT; ELECTRICAL SYSTEM. The Central Information Display goes black intermittently due to resets of the Head Unit \(HU\-H3\). FaultB7F8F9 â“ âHU\-H: Resetâ will be stored in the HU\-H3.
- [B540421](/bulletins/10244239.md), 2023-11-01, Service bulletin: VISIBILITY:SUN/MOON ROOF ASSEMBLY; STRUCTURE. This situation can result in two customer complaints: 1. Wind noise 2. Excess water entry
- [B652823](/bulletins/10242874.md), 2023-10-01, Service bulletin: EQUIPMENT. Customers may be experiencing one or more of these following issues with Bluetooth operation: Bluetooth cannot be switched on or off in the head unit \(HU\-H4\) Paired mobile devices cannot be deleted Customer is unable to make phone calls or stream music with mobile device Customer is unable to connect a new mobile device via Bluetooth Mobile device does not automatically reconnect via Bluetooth in the next drive cycle \(after short sleep cycle\)
- [B610220](/bulletins/10242699.md), 2023-09-25, Service bulletin: VISIBILITY:WINDSHIELD; VISIBILITY:WINDSHIELD WIPER/WASHER; STRUCTURE. ?When driving over uneven pavement or cobblestones, a knocking noise is present from the passenger side front area \(A pillar\). Once the vehicle is driven on a flat, even surface; the noise is no longer present.
- [B540123](/bulletins/10242696.md), 2023-09-25, Service bulletin: STRUCTURE; VISIBILITY:SUN/MOON ROOF ASSEMBLY. ?Water leaking into the vehicle from the headliner/microphone area.

JSON: [/v1/bulletins/10205096](/v1/bulletins/10205096)

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