NHTSA ID Number: 10177623
Manufacturer Communication Number: B340320
TSB/Document Date: 2020-07-27
Summary
PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH STANDARD BRAKES: The CBS data and Check Control (CC) message shows the rear axle brake pads are worn, and the vehicle has less than 15,500 miles. Increased residual braking forces in the rear axle brake calipers caused by production-related deviations on the surface of the piston ring seal.
7/6/2020
34 03 20_PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH STANDARD BRAKES
SIB 34 03 20
PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH
STANDARD BRAKES
2020-06-02
MODEL
E-Series
Model
Description
G20
3 Series Sedan
G29
Z4 Roadster
Production Date
November 1, 2018 to December 31,
2019
November 1, 2018 to December 31,
2019
Affected Option
Code
Standard brakes
Standard brakes
SITUATION
The CBS data and Check Control (CC) message shows the rear axle brake pads are worn, and the vehicle
has less than 15,500 miles.
CAUSE
Increased residual braking forces in the rear axle brake calipers caused by production-related deviations on
the surface of the piston ring seal.
CORRECTION
Improved rear axle brake calipers.
PROCEDURE
1. Is the rear axle brake pad wear indicator and the CBS data display showing worn rear brake pads
(service due)?
Yes, proceed to next step
No, no further action required
2. Does the vehicle have under 15,500 miles or does the rear brake pads have under 15,500 accumulated
miles since the last replacement?
Yes, proceed to next step
No, replace brake pads under maintenance program or as customer pay as applicable
3. Replace both rear axle brake calipers as per REP 34 21 745* “Removing and installing/replacing rear left
or right brake caliper”. Install new pads and wear sensor.
* NOTE: The model G30 must be used when searching the repair instruction. Repair instructions are not
currently available in ISTA or AIR for G20.
PARTS INFORMATION
Obtain and confirm the part numbers for your specific vehicle by entering the chassis number in either ETK
or AIR which takes into account specific equipment and/or options.
For 330i, 330i xDrive; and Z4 sDrive30i
Part Number
Description
34 20 8 836 841
Caliper housing left
34 20 8 836 842
Caliper housing right
Refer to ETK
Repair kit, brake pads asbestos-free
Refer to ETK
Brake pad wear sensor, rear
81 22 0 142 156
Brake fluid (12 oz btl)
Quantity
1
1
1
1
As needed
Copyright ©2020 BMW
of North America, Inc.
1/3
7/6/2020
34 03 20_PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH STANDARD BRAKES
For M340i, M340ix and Z4 M40i
Part Number
Description
34 20 8 836 845
Caliper housing left
34 20 8 836 846
Caliper housing right
Refer to ETK
Repair kit, brake pads asbestos-free
Refer to ETK
Brake pad wear sensor, rear
81 22 0 142 156
Brake fluid (12 oz btl)
Quantity
1
1
1
1
As needed
And:
Bulk Material - Sublet
Part Number
83 12 2 296 187
Description
Brake Pad Paste - 5 ml
Quantity
1
WARRANTY INFORMATION
For those vehicles with an “active” maintenance program, when the repair outlined in the Procedure section
applies and is performed, this repair will address and replace the following maintenance service tasks:
Rear brakes service (Pads are due with under 15,500 miles accumulated); and the
Brake fluid service (When it shows Recommended, Due or Bundling Eligible)
Please be sure to explain on the repair order and in the claim comments for the Standard Scope line item
that one or both of the maintenance service tasks listed above were addressed by performing the repair
outlined in this Service Information Bulletin.
If any additional required maintenance service tasks are required and performed, when eligible, claim these
items normally and reset the CBS data.
Defect Code:
3421022900
Brake pad, rear jammed/stuck
As outlined in the Procedure section (Step 2, Yes) and in conjunction with the above, rear caliper
replacement is covered under the terms of the BMW
New Vehicle Limited Warranty for Passenger Cars and
Light Trucks.
Labor Operation
34 00 506
And:
34 21 755
Description
Venting brake system (Plus work)
Labor Allowance
Refer to AIR
Replacing both rear axle brake calipers (including the
brake pads)
Refer to AIR
Replacing both rear axle brake calipers (including the
brake pads) (Wheels removed)
Refer to AIR
Or:
34 21 760
Refer to AIR for the corresponding flat rate unit (FRU) allowances.
Please also follow the Technical Data information and applicable Service Information Bulletins for rear brake
discs inspection and servicing with the replacement of the brake pads.
And, as needed:
Sublet – Bulk Materials (RO and Claim Comments Required)
Copyright ©2020 BMW
of North America, Inc.
2/3
7/6/2020
34 03 20_PREMATURE WEAR OF THE REAR AXLE BRAKE PADS WITH STANDARD BRAKES
Sublet See the sublet
Code reimbursement
4
calculations below
Reimbursement for the repair-related bulk material (Do not use the
BMW
part numbers for claim submission)
Sublet reimbursement calculation for claiming the applicable repair-related bulk material (BMW
part
numbers) is at the dealer net price amount for the quantity used plus your center’s handling.
Enter this material cost in sublet and itemize the amount on the repair order and in claim comment section.
Copyright ©2020 BMW
of North America, Inc.
3/3
- Mixes well with conventional fluids
- Low-moisture formula provides excellent vapor lock...
- Ideal for hydraulic and disc brakes
- Provides an extra margin of safety in extreme braking...
- Mix of polyglycol ethers ensures hot brake-system operation...
- Excellent for ABS, disc and drum brake systems
- Delivers braking power when needed by avoiding a spongy...
- Both wet and dry boiling points exceed the minimum...
Last update on 2026-06-23 / Affiliate links / Images from Amazon Product Advertising API
If the PDF is very large, it may not load in the preview below.
Some older TSBs had multiple PDFs — visit the NHTSA Website to view all PDFs.
If the TSB PDF does not show, download or view it on the NHTSA Website.
Click on the (+) Plus Sign
Then Click on Associated Document(s)
Search NHTSA Database for Recalls
Search NHTSA Database for Vehicle Investigations
View Latest Vehicle Investigations
Search NHTSA Database for Vehicle Complaints
View Latest Vehicle Complaints
TSB/Document ID: B340320
Replacement Service Bulletin Number:
MFR Communication Date: 2020-06-01
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: SERVICE BRAKES, HYDRAULIC
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
- WHY CHOOSE THE 2025 CR MAX -Upgrade the latest diagnostic capabilities for all vehicles after 1996: upgrade to 49+maintenance services; 46 extra specific functions; real all systems/all control modules diagnose; over 40K+ bidirectional actuation tests for diagnosing all control moduels of cars; Powerful full OBD2 Functions; built-in ECU Coding for BMW
/ Audi
/ VW
/ RollsRoyce; Fr ee V.A.G Guide Function; Battery retistration for new battery adaptation and more. It covers all vehicle diagnostic services and some special professional vehicle maintenance servces, assists you to do home DIY vehicle maintenance or car repair as a pro technician. - NEWEST IN INNOVATION FULL OBD2 SERVICES- iCarsoft auto car diagnostic scanner compatible with CAN-FD, CR MAX can do it all-reads and clears trouble codes, ALL SYSTEM DIAGNOSIS such as engine, transmission, ABS and airbag etc. CR MAX code reader for all cars can perform I/M Readiness, Live Data, Freeze Frame, Vehicle Information, Monitor Test, On-Board Monitor, E vap System Test,O2 Sensor Test,DTC Library Lookup,etc. (Warm Tips: If you car is after 2023,please contact us for compatibility; 3. It comes with 16PIN OBD2 diagnostic adapter, please check your car diagnostic socket if it is 16pin socket, if your car is 14pin diagnostic socket please contact us for the solution.)
- 49 RESET+ 46 SERVICES- Performs: Oil Reset, EPB,SAS,Throttle, D-P - F, Battery, ABS, Injector, TPMS, Suspension, AC, Head Lamp, Body Stablity, Engine, Tramsmission, Airbag, Seat, Door-Win-Roof, Fuel Pump, Door, E-G- R.+21 NEWEST SERVICES( Need update scanner)-AdBlue, Clutch, Crankshaft, High Voltage Battery
, Cruise Control, NO xSensor, Rain Sensor, Stop And Start, Turbocharger, Head Up Display, Radar Camera, Vehicle Setup, Cyliner Misfire Check,Speedlimitassist, ControlUnitReset,OxygenSensor, Seatbelt. Extra 46+ extra services based on car brand.(Tips: Quantity of reset/ calibration fucitons are based on car system that your vehicle model has) - REVOLUTIONARY 40000+BIDIRECTIONAL ACTIVE TESTS: Upgraded CR Max scanner equip with numberous of actuational test items for covering all available vehicle control modules, no longer only do simple light test or window test like other scanners, performs hardware modules test and software control modules test for checking car units or new updated control moduels work well or not after maintenance/ repair/ re-installation/ control system updated (Example for Benz- Roller Sun Blind test; Backup Camera test ;Self-test; EPB test; Transport Mode test;Boost Pressure Positioner test; Fuel Pump test; AND MORE!!).(Warm tip: The available test items are based on control modules your car has)
- ECU CODING+ BATTERY REGISTRATION- Powerful ECU Coding service for BMW
/MINI
/RollsRoyce / Audi
/VW
/Seat/Skoda/Bentley
/Bugatti
/Lamborghini
, Improves Engine Power Performance and Optimizes Fuel Efficiency and Match New Hardware Unit to car and Customized a comfortable Driving Modes and Fixes & Updates Original Software Bug. The battery test function for checking car battery health, perform battery reset (BMS ) for replacing a damaged or aging car battery with a new one and register new battery to car ECU
- 【Looking for More Professional Vehicle Scan Tool?】iCarsoft E660 2026 Upgrade Version OBD2 scan tool can do it all-reads and clears trouble codes on Engine system, ABS system, Transmission system and Airbag system, And with 6 reset function. It covers more than 59 vehicle makes from 1996-2023 models ( included most USA/ Asia / EU vehicle brand) with full OBDII. (As every car model has its-owned specific car system and ECUs, not all car models have full car ECUs which may prevent the scanner from performing all listed system diagnostics or reset services. Therefore, please email to us with car VIN and services required to do scanner's services for a compatibility check before purchasing.)
- 【OE-Level 4 Systems OBD2 Scanner】iCarsoft E660 2026 Upgrade Version diagnostic scanner offers comprehensive OBDII services, allowing you to quickly scan Engine system. It supports functions such as reading and erasing codes, checking I/M readiness, viewing freeze frame data, performing O2 sensor tests, conducting on-board monitoring, testing the evap system, auto VIN retrieval, and reading both generic and specific codes, as well as DTCs and battery tests.
- 【4 Systems Diagnosis for 10000+ Vehicles】 iCarsoft E660 2026 Upgrade Version adopts unique diagnostic software, works well for most Porsche
, Benz, BMW
, US Ford
, Land Rover
, Jaguar
, Audi
, VW
, Volvo
, Honda
, Nissan
, Infiniti
, Toyota
, Lexus
, Scion
, Isuzu
, Hyundai
, Kia
, Daewoo, Mazda
, Sprinter
, Mini
, Seat, Skoda, SAAB
, EU Ford
, Holden, AUS Ford
, Acura
, Subaru
, Mitsubishi
, Dacia, Renault, Fiat
, GM, Chrysler
, Citroen, Peugeot, Opel, Smart,Suzuki
, Vauxhall, Alfa-Romeo, Lancia and etc. - 【6 Reset Services】iCarsoft E660 2026 Upgrade Version is a diagnostic tool that offers professional maintenance services, including Oil Reset, EPB, BMS, ETC, SAS, TPMS Reset. It can help you easily reset oil change indicators, recalibrate steering angle sensors, relearn replaced electric parking brake and so on. For optimal vehicle performance and maintenance convenience. (Tips: Please update the softwareafter receiving the product to obtain new service functions)
- 【118+ Real Time Record & Live Graph View】iCarsoft E660 2026 Upgrade Version can automatically record vehicle text history and identify vehicle information. Preserve real-time data information. View & Graph Live Data. Support Data Review and Print. 15 languages: English, German, Dutch, Spanish, French and so on. We promise to offer Lifetime updates (Lifetime free Update via PC), and confidence in products. We also provide 1 year warranty + extra lifetime hardware free repair if you need it in the future. We prioritize user experience & strive to meet your expectations. Please do feel free to reach out to us if you have any question or problem about the usage.
- 【All-in-One Diagnostic Tool for Porsche
+ 2 Extra Vehicle Brands】New POR V4.0 is a professional car scanner specifically engineered with dedicated software pre-installed for Porsche
. You can also download 2 additional software packages FOR FREE from 26 supported brands (e.g., for Benz, for BMW
, for Audi
, for Land Rover
).Upgraded to adopt quad-core 1.3GHz processor and HD touchscreen and professional diagnsotic OS for faster& smooth diagnsotic.LIFETIME FREE UPDATES, NO SUBSCRIPTION COST! PLEASE TELL US YOUR CAR INFORMATION TO OBTAIN A LIST OF ALL COMPATIBLE SERVICES FOR YOUR CAR FIRST (FOR EXAMPLE: BATTERY REGISTRATION FUNCTION IS NOT COMPATIBLE WITH PORSCHE
997.2) - 【29 MAINTENANCE SERVICES FOR PORSCHE
SERIES CARS】 It can perform the 29 reset service for Porsche
series cars-Oil Reset; SAS; EPB; BMS; ETC; DP ; ABS Bleeding; Injector Coding; TPMS; Air Suspension; Air Conditioner; Head Lamp; Body Stablity Control; Engine Control; Transmission; AirBag; Seat; DWR; MIS; EG; ODO; Clutch; High Voltage Battery
; Cruise Control; Radar/Camera; Vehicle Setup,etc. Up to 49 vehicle-maintenance-services for the extra 2 vehicle brands you installed (Tip: Not all services will be worked on every car mode. Some vehicle models may be lack of certain ECU-control modules to make some services may not work). - UPGRADE SERVICES: Breaks down 29 services to 234 sub-service for car owners/machinist to perform maintenance based on corresponding sub-modules! The detailed sub-service for sub-modules assist to perform precise vehicle maintenance.Improving the accuracy of car maintenance and reducing potential failure risks caused by whole-module maintenance to main modules.such as Oil Reset is refined into Reset maintenance interval/Reset service interval/Service Reset; Engine Control Reset is refined into Delete adaptation data/Short tests/System tests/Swirl-flap actuator/Bleeding high temperature coolant circuit and more.(sub-services vary based on vehicle model/year)
- 【EXTRA VEHICLE MAINTENANC SERVICES FOR SPECIFIC SYSTEMS】Have no ability to perferm calibration to special/specific systems/modules? This OBD2 scanner solve your troubles- for common systems/modules & for specific sytems/modules, assist you to perform diagnsing/calibration/reset/relearn services for non-common modules to finish your car maintenance/ diagnostic (eg: Central Computer system/module :Function activation/Multimedia interface test/AM Field Strength/Current FM Field Strength/FM Field Strength/MOST system reserve/Self-test/Deactivate Production Mode/Reset to factory settings/MOST System Test). (Tip: The services vary based on the vehicle brands)
- 【 MORE PROFESSIONAL BI-DIRECTIONAL ACTUATION TESET 】Exclusive POR V4.0 comes with powerful bidirectional testing capability,do actuaction test for deeper unit-checking after replacement or overhaul (1333 test items for Porsche
, like:Fuel high-pressure fuel injector 1-4, Empty tank, Radiator fan, OTA-FC Connectivity, backrest, Backup battery, and more; 2136 test items for Audi
; 1670 test items for Benz; 1599 test items for Volvo
; 1360 test items for VW
; 2705 test items for GM etc.). Help to check your car units work well or not after vehicle maintenance or daily car-body check, keep drives always in safety.(Warm tip:The quantity of test item is based on the units your car has)
Last update on 2026-06-23 / Affiliate links / Images from Amazon Product Advertising API
This product presentation was made with AAWP plugin.




