Mercedes-Benz · Known Issues
2021 Mercedes-Benz GLB Problems: 11 Known Issues
2021 model year · 1,800+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2021 model year · 1,800+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
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According to Au7o's analysis of 1,800+ owner reports, the 2021 Mercedes-Benz GLB has 11 documented known issues, with 3 rated critical. The most serious are ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679), M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss) and Driver Airbag Module Not Built to Specification (Recall 22V078) ($0-$0 repair). The most commonly reported issue is 8G-DCT Transmission Shudder with 800 owner reports. Across all issues with published estimates, repair costs range from $150 to $2,500. DIY maintenance guides at au7o.io.
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According to Au7o's analysis of 1,800+ owner reports, the 2021 Mercedes-Benz GLB has 11 documented issues. The most frequently reported are: ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679), M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss), Driver Airbag Module Not Built to Specification (Recall 22V078). Of these, 3 are rated critical and should be addressed promptly.
The 2021 Mercedes-Benz GLB has 11 known issues documented across 1,800+ owner reports. 3 issues are rated critical: ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679) and M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss) and Driver Airbag Module Not Built to Specification (Recall 22V078). 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.
Repair costs for known Mercedes-Benz GLB issues range from $0 to $2,500, 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.
Recall 22V679 directly covers four model-year 2021 GLB 250 vehicles whose ESP control units may have been mechanically damaged during logistics. Moisture can enter the unit and disable functions including anti-lock braking and electronic stability control; a thermal event also ca… Severity: high.
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: high.
Mercedes-Benz determined that a number of Model Year 2021 GLB-Class (X247) vehicles may have left the plant with a driver airbag module that does not conform to specification. Because the module is not to spec, correct deployment behavior in a crash cannot be assured, which is a… Repairs typically run $0-$0. Severity: high.
The 8G-DCT dual-clutch transmission exhibits shudder and hesitation during low-speed maneuvers and from a standstill. While improved over the earlier 7G-DCT, the 8G-DCT still uses a wet clutch design that can judder when the clutch packs wear or the software calibration is outdat… Repairs typically run $150-$2,500. Severity: medium.
On certain 2021 GLB (X247) vehicles the ride-height level sensor linkage at the rear axle - the input the automatic headlamp leveling system uses to work out how far the tail has squatted - was not installed correctly at the factory. With the linkage mounted wrong, the system rea… Repairs typically run $0-$0. Severity: medium.
An error in the communication module's embedded SIM-card software can cause a loss of mobile-network connection on GLB-Class vehicles, which disables the automatic emergency call (eCall / Mercedes me emergency) function. In a crash the vehicle may fail to automatically alert emer… Repairs typically run $0-$0. Severity: medium.
Like other Mercedes direct-injected turbo engines, the M260 in the GLB (and the 1.3L M282 in the GLB 180/200) accumulates carbon deposits on the intake valves and intake tract over time because fuel is injected directly into the cylinder and never washes the back of the valves. T… Repairs typically run $300-$600. Severity: medium.
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.
The MBUX system freezes, reboots, or displays glitches. Apple CarPlay and Android Auto connections trigger instability in the head unit, and the voice assistant ("Hey Mercedes") intermittently stops responding. Repairs typically run $0-$1,500. Severity: low.
The panoramic sunroof develops creaking and popping noises, particularly in temperature extremes and over rough roads. The large glass panel flexes differently than the metal roof structure, creating friction at the seal interfaces. Repairs typically run $0-$400. Severity: low.
AMG GLB35 owners report a loud squeal from the brakes when coming to a stop under light pedal pressure, present from delivery and persisting well past the break-in period. The AMG uses a higher-friction pad compound on larger front rotors than the GLB250, and that compound plus t… Repairs typically run $0-$600. 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.