2020 Mercedes-Benz GLB Problems: 8 Known Issues
2020 model year · 600+ owner reports · Updated November 2026
According to Au7o's analysis of 600+ owner reports, the 2020 Mercedes-Benz GLB has 8 documented known issues, with 3 rated critical. The most serious are Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990), Water can enter the front footwells and damage control units — recalls 20V246 and 21V403 and Fuel can leak between the fuel rail and injectors — recall 21V961 ($0-$0 repair). The most commonly reported issue is MBUX display may stay black or reboot after start-up — recall 21V354 with 600 owner reports. DIY maintenance guides at au7o.io.
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All 8 Known Issues








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Frequently Asked Questions
What are the most common Mercedes-Benz GLB problems?
According to Au7o's analysis of 600+ owner reports, the 2020 Mercedes-Benz GLB has 8 documented issues. The most frequently reported are: Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990), Water can enter the front footwells and damage control units — recalls 20V246 and 21V403, Fuel can leak between the fuel rail and injectors — recall 21V961. Of these, 3 are rated critical and should be addressed promptly.
Is the Mercedes-Benz GLB reliable?
The 2020 Mercedes-Benz GLB has 8 known issues documented across 600+ owner reports. 3 issues are rated critical: Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990) and Water can enter the front footwells and damage control units — recalls 20V246 and 21V403 and Fuel can leak between the fuel rail and injectors — recall 21V961. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Mercedes-Benz GLB problems?
Repair costs for known Mercedes-Benz GLB issues range from $0 to $1,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2020-2021 Mercedes-Benz GLB Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990)?
Recall 21V990 directly covers 21,219 model-year 2020 GLB 250 vehicles and 6 model-year 2021 AMG GLB 35 vehicles whose front-axle integral carrier may have insufficient corrosion protection. After several years and under specific environmental influences, corrosion may impair stru… Severity: high.
What is the 2020 Mercedes-Benz GLB Water can enter the front footwells and damage control units — recalls 20V246 and 21V403?
Because of a production deviation, the body might not be sealed at the front wheel wells, so water can enter the front occupant footwells. That might impair control units and other electrical components there: the instrument cluster might show no information, and the engine might… Severity: high.
What is the 2020 Mercedes-Benz GLB Fuel can leak between the fuel rail and injectors — recall 21V961?
Because the fuel rail and injectors might not have been cleaned properly before assembly, trapped particles can damage the seal between the fuel rail and a fuel injector. Over the life of the vehicle this might let fuel leak into the engine compartment, where it could contact hot… Repairs typically run $0-$0. Severity: high.
What is the 2020-2021 Mercedes-Benz GLB MBUX display may stay black or reboot after start-up — recall 21V354?
Under very specific conditions the MBUX multimedia system might not start, leaving the display black, or could reboot unintentionally about 50 seconds after start-up. While that happens the rearview camera image might not be displayed or might be interrupted, which could increase… Repairs typically run $0-$1,500. Severity: medium.
What is the 2020-2021 Mercedes-Benz GLB Emergency call may not work if the communication module SIM software is disabled — recall 22V365?
The communication module's SIM card software might inadvertently become disabled, so the module cannot connect to a mobile phone network. Both the manual and automatic emergency call (eCall) functions would then be unavailable, which could preclude or delay the arrival of emergen… Repairs typically run $0-$0. Severity: medium.
What is the 2020-2022 Mercedes-Benz GLB M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss)?
Mercedes-Benz extended the exhaust-valve-system warranty to 15 years or 150,000 miles for certain model-year 2020-2022 GLB 250, GLB 250 4MATIC and AMG GLB 35 vehicles. The notice identifies valve-guide and/or seat-ring wear from increased lateral forces, which can cause cylinder… Severity: medium.
What is the 2020-2021 Mercedes-Benz GLB Rearview Camera Fails to Display (Black Screen) Due to Software Error (Recall 22V232)?
Recall 22V232 directly covers 15,787 model-year 2020-2021 GLB 250 vehicles and 177 model-year 2021 AMG GLB 35 vehicles whose rearview-camera software may fail to show the required image after reverse is selected. The center display may instead retain the previous image or show a… Severity: medium.
What is the 2020 Mercedes-Benz GLB Rear brake pad inspection gauge and instructions may be missing — recall 23V732?
Because of a documentation error in the production control system, the vehicle might not have the inspection gauge for checking rear brake pad wear, and the owner's manual might not explain how to use it, so the vehicle does not comply with FMVSS 135. The front pads have an elect… Repairs typically run $0-$800. Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
