2020 Mercedes-Benz GLB Problems: 11 Known Issues

On the 2020 Mercedes-Benz GLB 2.0L turbo I4 (M260), recall 20V246 directly covers 26 model-year 2020 GLB 250 vehicles whose body seam in the wheel-well area may allow water into the front footwells. Water can damage control units, causing the instrument cluster display to fail, an engine no-start or an engine stall. The 26-vehicle population is not an owner-report count, and the recall does not establish that every water leak shares this path.

On the 2020-2021 Mercedes-Benz GLB 2.0L turbo I4 (M260), 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 black screen with an inoperability message; the recall explicitly says the rearview image does not deactivate or freeze. These population counts are not owner reports.

On the 2020-2025 Mercedes-Benz GLB, 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.

On the 2020-2022 Mercedes-Benz GLB 2.0L turbo I4 (M260), 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 misfires and an illuminated malfunction indicator lamp. Manufacturer communication 11028267 separately identifies a leaking valve seat, requires cylinder leakage testing and calls for complete cylinder-head replacement only when valve-seat damage is confirmed. Coverage and parts are VIN-specific; neither document establishes a universal manufacturing defect, owner-frequency rate or automatic cylinder-head replacement.

On the 2020-2024 Mercedes-Benz GLB, 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. This leads to unstable idle, hesitation, reduced power and worse fuel economy as mileage climbs, and German sources note the 1.3L can also develop coked injectors. It is a wear/maintenance issue, not a recall.

On the 2020-2021 Mercedes-Benz GLB 2.0L turbo I4 (M260), 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 structural durability or connections to other components, potentially affecting steering and increasing crash risk. The recall reported no warning inherent to the failure mechanism and no field complaints at the time; 21,219 is a recall population, not an owner-report total.

On the 2020 Mercedes-Benz GLB M260, on M260 2.0T GLB250 vehicles built in the affected window, metal or plastic particles left over from the production process can become trapped between the fuel rail and the fuel injector sealing surface. Over time those particles score and damage the seal, letting pressurized gasoline weep out at the rail/injector joint into the engine compartment. Fuel that contacts hot exhaust or turbo components creates a fire risk. Owners typically notice a raw fuel smell after shutdown, a fuel odor in the cabin at idle, or fuel staining on top of the engine cover before any warning light appears. Mercedes-Benz filed NHTSA campaign 21V961000 (MBUSA 2022030003) in December 2021 covering a very broad list of gasoline models, with the 2020 GLB250 included alongside the closely related A220 and CLA250.

On the 2020-2025 Mercedes-Benz GLB 2.0L turbo I4 (M260), 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 outdated.

On the 2020-2021 Mercedes-Benz GLB 2.0L turbo I4 (M260), 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 emergency services, and connected services may stop working. This is relevant in the EU where eCall is mandated. Covered by NHTSA recall 22V365 (a Mercedes campaign spanning 2017-2022 models, including the 2020-2021 GLB 250 and 2021 AMG GLB 35).

On the 2020-2025 Mercedes-Benz GLB, 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.

On the 2020 Mercedes-Benz GLB, the GLB250, like its A-Class/CLA/GLA platform mates, uses an electronic wear sensor on the FRONT brake pads only; the REAR pads have no sensor and are meant to be checked mechanically using a small inspection gauge supplied with the vehicle, with the procedure documented in the owner's manual. Mercedes-Benz found that roughly 42,700 vehicles - including the 2020 GLB250 - left the factory without that inspection gauge and without the manual pages explaining it. Because there is no dash warning for rear pad wear on these cars, an owner can run the rear pads down to metal-on-rotor with no indication at all, which is why NHTSA treated it as a federal safety standard non-compliance (campaign 23V-732) rather than a documentation error.