# Service bulletin SIB340721

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: 10204625
- Published by NHTSA: 2021\-12\-13
- Manufacturer's number: SIB340721
- Manufacturer's date: 2021\-07\-01
- NHTSA component: SERVICE BRAKES, HYDRAULIC:POWER ASSIST:HYDRAULIC

## NHTSA's summary

When starting the vehicle vehicle at standstill, various yellow Check Control Messages CCMs appear. ID code 00042: Brake system. Additional notes: Avoid abrupt braking as far as possible. Drive at a moderate speed. Have it checked by your nearest Service Center. ID code 2046: Braking force assistance. Additional notes: Braking force assistance failure. Higher pedal force required for vehicle deceleration. Drive at a moderate speed. Have it checked by your nearest Service Center.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2021/MC-10204625-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2021/MC-10204625-9999.pdf)

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

## Components

Brakes

## Vehicles listed

- 2017 to 2019 BMW 740E
- 2017 to 2021 BMW 740I
- 2016 to 2017 BMW 740LI
- 2020 BMW 745E
- 2018 to 2019 BMW 750I
- 2016 to 2019 BMW 750LI
- 2021 BMW 750LI
- 2020 to 2021 BMW 840I
- 2018 to 2021 BMW B7 ALPINA
- 2021 BMW M3
- 2021 BMW M4
- 2017 to 2021 BMW M760I
- 2020 to 2021 BMW M8
- 2020 BMW M8 GRAN COUPE
- 2019 BMW M850I
- 2020 to 2021 BMW M850I
- 2019 BMW M850XI
- 2019 to 2021 BMW X5
- 2020 to 2021 BMW X6
- 2020 BMW X6 M
- 2019 to 2021 BMW X7

## Recalls for the same vehicles and component

- [21V089000](/recalls/nhtsa/21V089000.md), 2021-02-18: SERVICE BRAKES, HYDRAULIC:CRITICAL FASTENERS; SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC
- [2021061](/recalls/tc/2021061.md), 2021-02-10: Brakes
- [21V062000](/recalls/nhtsa/21V062000.md), 2021-02-10: SERVICE BRAKES, HYDRAULIC:POWER ASSIST:HYDRAULIC; SERVICE BRAKES, HYDRAULIC

## Other bulletins for the same vehicles and component

- [B340714](/bulletins/10244237.md), 2023-11-01, Service bulletin: SERVICE BRAKES, HYDRAULIC. Functional noises \(squealing/honking\) when braking shortly before the vehicle comes to a stop. CAUSE Material\-
- [SIB510623](/bulletins/10236228.md), 2023-05-15, Service bulletin: AIR BAGS; EXTERIOR LIGHTING:HAZARD FLASHING WARNING LIGHTS:SWITCH; PARKING BRAKE; EXTERIOR LIGHTING. The hazard light \(aka emergency flasher\) button gets stuck in the ON or OFF position when actuated.
- [B340921](/bulletins/10233158.md), 2023-03-20, Service bulletin: SERVICE BRAKES. A turbine\-like noise can be heard from the rear axle while deceleration during the first 300 miles of operation when braking from low speed.
- [SIB170220](/bulletins/10224198.md), 2022-10-17, Service bulletin: FUEL SYSTEM, GASOLINE; SERVICE BRAKES; ENGINE AND ENGINE COOLING. Symptom 1: There are traces of coolant leaking under the vehicle, or there is significant pressure released along with coolant loss when opening the low temperature cooling system reservoir \(engine cold\). The following fault code may also be stored in the DME: 20A201 \- Charge air cooling system: Coolant pump protective function activated due to dry running Symptom 2\*: The air conditioning may have low cooling output with the following fault stored in the IHKA: 80120A \- Compressor: Shut down due to overpressure in refrigerant system. Symptom 2 is an additional symptom related to Symptom 1. Diagnose the IHKA fault with ISTA test plans if it is the only fault stored \(if no DME faults are stored related to coolant loss, this bulletin repair does not apply\).
- [B330120](/bulletins/10212789.md), 2022-05-31, Service bulletin: SERVICE BRAKES. There is a shudder or jerking feeling coming from the rear of the vehicle at low speeds and low engine loads while turning. Incorrect actuating pressure in the M\-differential clutch plates.
- [B341019](/bulletins/10203336.md), 2021-11-08, Service bulletin: SERVICE BRAKES, HYDRAULIC. Inform the customer during a consultation that the M Compound \(standard equipment\) and M Carbon Ceramic \(optional\) brakes are high\-performance brake systems which are designed for sporty, dynamic driving styles. As a side effect of the highest possible brake performance, customers are likely to hear noises due to the extremely resilient materials. In the same conversation, inform the customer that his/her braking performance can help ensure that the noises do not occur or disappear quickly.
- [B341019](/bulletins/10201141.md), 2021-09-07, Service bulletin: SERVICE BRAKES, HYDRAULIC. Inform the customer during a consultation that the M Compound \(standard equipment\) and M Carbon Ceramic \(optional\) brakes are high\-performance brake systems which are designed for sporty, dynamic driving styles. As a side effect of the highest possible brake performance, customers are likely to hear noises due to the extremely resilient materials In the same conversation, inform the customer that his/her braking performance can help ensure that the noises do not occur or disappear quickly.
- [B511121](/bulletins/10198904.md), 2021-07-06, Service bulletin: PARKING BRAKE. ROOF TRIM STRIP LOOSE AT REAR: The roof trim strip may be loose at the last \(rearmost\) clip as shown. This can occur on either side of the roof, or on both sides.
- [B360121](/bulletins/10194298.md), 2021-05-24, Service bulletin: EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; SERVICE BRAKES, AIR:DISC. Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal stresses during rapid heating and cooling of the brake discs. Braking from high speed with cold brake components \(less than 212 degrees F\) increases the likelihood of cracks to form.
- [B340521](/bulletins/10194297.md), 2021-05-24, Service bulletin: EQUIPMENT; SERVICE BRAKES, AIR:DISC; EQUIPMENT ADAPTIVE/MOBILITY. Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal stresses during rapid heating and cooling of the brake discs. Braking from high speed with cold brake components \(less than 212 degrees F\) increases the likelihood of cracks to form.

JSON: [/v1/bulletins/10204625](/v1/bulletins/10204625)

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