2020-2026 Mercedes-Benz GLB Problems & Issues

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 stall while driving or not start, increasing the risk of a crash. Occupants might notice wet carpets in the front footwells and fogged windows. Applies to: Certain 2020 GLB 250: 26 vehicles built July 26, 2019 to January 24, 2020 (recall 20V246), expanded by recall 21V403 to 5,680 vehicles built July 26, 2019 to July 16, 2020 because plant rework could not be confirmed on all of them. Both use Mercedes campaign 2020070009. Eligibility is by VIN.

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.

The facelifted GLB (2024 onward) gained a 48-volt mild-hybrid system with a second-generation belt-driven starter-generator (RSG), so the car now depends on a small 48V lithium-ion battery for engine restarts, coasting, and recuperation in addition to the conventional 12V battery. Owners on the MBWorld GLB forum report repeated 12V battery discharge - dead or weak battery after short periods parked, requiring frequent jump starts or a tender. Mercedes-Benz opened service campaign 2025100004 (late October 2025) to update the 48-volt on-board electrical system battery software, because a communication error can occur when the 48V lithium-ion battery is reactivated during reinitialization; the same campaign covers CLA and GLA. Per the campaign bulletin, the system can store this error and illuminate the check engine (malfunction indicator) lamp unnecessarily; the bulletin does not link it to 12V battery drain. Separately, GLB owners across model years report the small 1.2 Ah auxiliary battery plus short-trip driving leaves the 12V battery chronically undercharged.

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 direct occupant-protection defect rather than a nuisance fault. Nothing about the condition is visible or detectable by the driver - there is typically no airbag warning lamp and no stored fault code - so the only way to know a vehicle is affected is a VIN check against the campaign. This is separate from the eCall and ESP campaigns that also hit the 2021 GLB.

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 emergency responders and increase the risk of injury after an emergency. Applies to: GLB250 2020-2021 and AMG GLB35 2021 are among the models NHTSA lists for recall 22V365, which Mercedes has carried out in waves. Eligibility is by VIN.

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 reads the load backwards: when the third row, rear seat, or cargo area is loaded and the rear of the vehicle sits down, the headlamp leveling motors tilt the beams UP instead of down. The result is significant glare toward oncoming traffic exactly in the loaded, family-hauling condition the GLB's optional third row invites. Mercedes-Benz AG decided on the recall May 2, 2022, notified dealers May 16, 2022, and mailed owner letters June 10, 2022.

Recall 22V679 covers only 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 cannot be ruled out. Warning messages or lamps may appear when the condition occurs.

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 electronic wear sensor and warning; the rear pads do not. Mercedes says the front pads always wear out before the rear pads, but if increased rear pad wear goes unnoticed the risk of a crash might increase. Applies to: Certain 2020 GLB 250 (9,881 vehicles in the recall). The report gives one production range, August 20, 2018 to May 15, 2020, for all the models in the recall. Eligibility is by VIN.

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. Mercedes-Benz attributes the noise to friction between the brake lining (pad) and the brake caliper at their contact points. Mercedes-Benz has issued a technical service bulletin (LI42.10-P-075968) covering squeaky front brakes on the GLA35/GLB35, confirming this is a factory-known condition rather than a one-off. Owners who accepted the common dealer answer that it is 'normal for a performance pad' generally still had the noise; those who got the TSB applied did not. GLB250 owners separately report rear rotor surface corrosion and early rotor replacement, a related low-mileage brake complaint on this platform.

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 states that this failure gives no warning and that no field complaints had been received at the time.

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 engine parts and a fire cannot be ruled out. The driver may notice a fuel odor, or a check engine light if the fuel rail pressure deviation exceeds thresholds. Applies to: Certain 2020 GLB 250 with the gasoline engine; the recall lists 9 GLB-Class vehicles within a production range of May 27, 2016 to May 14, 2020. Eligibility is by VIN.

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 the risk of a crash, and the vehicles do not conform to FMVSS 111. Mercedes traced it to MBUX software, including a hard-drive write that can be interrupted during shut-down. Applies to: Certain 2020-2021 GLB-Class vehicles (247 platform) with the MBUX multimedia system included in recall 21V354. Eligibility is by VIN.

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 depends on the VIN, and the cylinder head is replaced only when valve-seat damage is confirmed.