Mercedes-Benz · Known Issues

2020-2025 Mercedes-Benz GLB Problems: 10 Issues Every Owner Should Know

2020-2025 model years · 1,800+ owner reports · Updated June 2026

According to Au7o's analysis of 1,800+ owner reports, the 2020-2025 Mercedes-Benz GLB has 10 documented known issues, with 4 rated critical. The most serious are Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246) ($0-$0 repair), Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990) ($0-$0 repair), ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679) ($0-$0 repair) and M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss) ($0-$6,000 repair). The most commonly reported issue is 8G-DCT Transmission Shudder with 800 owner reports. Across all issues, repair costs range from $150 to $6,000. DIY maintenance guides at au7o.io.

All 10 Known Issues

On the 2020 Mercedes-Benz GLB 2.0L turbo I4 (M260), certain early 2020 GLB 250 4MATIC bodies were not sealed properly during manufacturing, allowing water to enter through the front wheel-well area into the front-occupant footwells. The water can reach and damage electrical components, resulting in the instrument cluster going blank or the engine stalling while driving with an inability to restart. NHTSA recall 20V246 (MBUSA campaign 2020070009) covers approximately 5,680 vehicles; the recall began July 31, 2020.

Common Symptoms

Instrument cluster goes blank
Engine stalls while driving
Vehicle will not restart
Wet front footwell carpet
Electrical malfunctions

How to Fix

Under recall 20V246, the dealer seals the body in the wheel-well area and inspects the front footwells for water intrusion, repairing damaged components at no charge. Owners should check their VIN at NHTSA/MBUSA and have the campaign performed if not already completed; watch for wet front carpets, which indicate intrusion.

Typical repair cost:$0 - $0

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Community Reported

High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

On the 2020-2021 Mercedes-Benz GLB 2.0L turbo I4 (M260), many 2020-2021 GLB-Class vehicles can fail to show the rearview camera image when reversing; instead the driver sees a black screen or the previous view plus a message that the rearview camera is inoperable. The defect is a software error affecting vehicles built with certain supplier control modules, and it removes a federally required backup-camera aid, increasing the risk of a backing crash. Covered by NHTSA recall 22V232 (part of a wider Mercedes campaign of ~126,000+ vehicles).

Common Symptoms

Black screen when reversing
Rearview camera inoperable message
Previous image stays frozen on screen
No backup camera view

How to Fix

Under recall 22V232, dealers (or an over-the-air update on some cars) install a rearview camera software update at no charge. Owners experiencing a black/frozen reversing screen should check their VIN for the open recall and have the update applied.

Typical repair cost:$0 - $0

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Community Reported

High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

Community Reported

600 owners

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.

This issue also affects: Mercedes-Benz A-Class, Mercedes-Benz EQB, Mercedes-Benz GLC

Common Symptoms

Touchscreen becomes unresponsive
System reboots showing Mercedes logo

How to Fix

Reboot MBUX by holding volume + track-forward for 10 seconds. Update to the latest software version. Factory reset the system if issues persist. Use a wired CarPlay/Android Auto connection for better stability.

What you need to fix it

The exact parts — OEM, plus what owners actually use. Skip the internet hunt.

From owners — upgrades & tips (600+ fixed this)

TipSwitch from wireless to wired CarPlay/Android Auto. The wireless protocol causes more MBUX crashes. A simple USB cable solves most freeze issues.

Part links may earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$0 - $1,500

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Medium Confidence600 reportsLast reported by owners Dec 2025Reviewed Mar 2026

On the 2020-2022 Mercedes-Benz GLB 2.0L turbo I4 (M260), the 2.0L turbo M260 four-cylinder used in the GLB 250 / GLB 35 (and the M264-related variants) suffers from premature wear of the exhaust valve seats and valve guides. The exhaust valves stop sealing, causing loss of compression in one or more cylinders, rough running and misfires. Mercedes acknowledged this as a manufacturing defect and issued a voluntary extended warranty in the US and Canada covering cylinder head replacement for up to 15 years / 150,000 miles on affected 2019-2022 A-Class, CLA, GLA and GLB vehicles. A 2026 NHTSA-posted TSB (MC-11028267) documents the valve seat/guide wear on M260/M264 engines. Left unaddressed it can progress to catastrophic piston/secondary damage that is NOT covered by the warranty extension.

This issue also affects: Mercedes-Benz G-Class, Mercedes-Benz A-Class

Common Symptoms

Rough idle
Engine misfire
Check engine light
Loss of power
Compression loss in one or more cylinders
Rough running when cold

How to Fix

Have misfire/rough-idle symptoms diagnosed promptly; the cylinder head is replaced under the 15yr/150k extended warranty if the VIN qualifies. Use only Mercedes-approved oil (MB 229.x) and premium fuel, and address any P030x misfire codes immediately to avoid uncovered piston damage. Out-of-warranty cylinder head replacement typically runs into thousands of dollars in parts and labor.

Typical repair cost:$0 - $6,000

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High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

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.

This issue also affects: Mercedes-Benz G-Class, Mercedes-Benz A-Class, Mercedes-Benz GLC

Common Symptoms

Unstable / rough idle
Hesitation on acceleration
Loss of power
Reduced fuel economy
Cold-start stumble

How to Fix

Periodic walnut-blasting / intake valve cleaning resolves the deposits; some owners use quality top-tier fuel and occasional intake cleaners as mitigation. Keeping up with oil changes using MB-approved oil reduces oil-vapor contribution from the PCV system. Walnut-blast cleaning typically costs roughly 300-600 USD depending on shop.

Typical repair cost:$300 - $600

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High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

On the 2020 Mercedes-Benz GLB 2.0L turbo I4 (M260), on certain 2020 GLB 250 vehicles, the integral carrier that supports the front axle may corrode, which can cause it to fail. A failure of the front axle carrier can compromise steering and suspension integrity and increase the risk of a crash. This is covered by NHTSA recall 21V990 and is part of a broader Mercedes campaign that also touched related A220 and AMG GLB35 models for front-axle corrosion protection.

Common Symptoms

Clunking from front end
Steering vibration or looseness
Suspension noise
Visible corrosion on front subframe

How to Fix

Under recall 21V990, dealers inspect the front axle carrier and replace it if corrosion is found, free of charge. Owners in road-salt/EU winter regions should verify the campaign has been completed and report any clunks, vibration, or steering looseness for inspection.

Typical repair cost:$0 - $0

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High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

On the 2021 Mercedes-Benz GLB 2.0L turbo I4 (M260), certain 2021 GLB 250 vehicles can have a damaged Electronic Stability Program (ESP) control unit. A damaged ESP unit can disable the anti-lock brakes (ABS) and electronic stability control (ESC) and can cause an electrical short circuit, increasing crash and fire risk. Owners separately report ESP/ABS warning messages and stability-control faults; NHTSA recall 22V679 addresses the unit defect.

Common Symptoms

ABS warning light
ESP/ESC warning message
Disabled anti-lock brakes
Disabled stability control
Electrical fault warnings

How to Fix

Under recall 22V679 the ESP unit is inspected and replaced as needed at no charge. If ABS, ESP or brake warning lights appear, stop relying on those systems and have the vehicle diagnosed; confirm the recall has been completed via VIN lookup.

Typical repair cost:$0 - $0

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High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

Community Reported

800 owners

On the 2020-2025 Mercedes-Benz GLB 2.0L M282 Turbo, 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.

This issue also affects: Mercedes-Benz A-Class, Mercedes-Benz B-Class

Common Symptoms

Shudder when pulling away slowly
Hesitation during low-speed parking maneuvers

How to Fix

Update the TCU software to the latest calibration. A transmission fluid change can improve clutch engagement feel. In persistent cases, the clutch assembly may need replacement under warranty.

What you need to fix it

The exact parts — OEM, plus what owners actually use. Skip the internet hunt.

From owners — upgrades & tips (800+ fixed this)

TipThe 8G-DCT improves significantly after the TCU software update. Ask the dealer for the latest calibration — several updates have been released since the GLB launch.

Part links may earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$150 - $2,500

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Community Reported

Medium Confidence800 reportsLast reported by owners Nov 2025Reviewed Mar 2026

On the 2020-2022 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 (Mercedes campaign spanning 2017-2022 GLB and other models).

Common Symptoms

Emergency call (eCall) not working
Mercedes me connectivity lost
No mobile network connection
Connected services unavailable

How to Fix

Under recall 22V365 the communication module software is updated, either over-the-air or at the dealer, at no charge. Owners should confirm Mercedes me emergency call is functional and have the software campaign performed if it shows as open for their VIN.

Typical repair cost:$0 - $0

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High ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

Community Reported

400 owners

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.

This issue also affects: Mercedes-Benz CLS-Class, Mercedes-Benz GLC

Common Symptoms

Creaking or popping noise from roof
Noise worsens in very cold or very hot weather

How to Fix

Lubricate the sunroof seals and guide rails with silicone-based lubricant. The dealer can apply felt tape to the contact points under warranty. Clean and lubricate the sunroof mechanism every 6 months.

What you need to fix it

The exact parts — OEM, plus what owners actually use. Skip the internet hunt.

From owners — upgrades & tips (400+ fixed this)

TipKrytox GPL-205 lubricant applied to the sunroof seals eliminates the creak. This is the same lubricant used in mechanical keyboards — it handles temperature extremes well and lasts 6+ months.

Part links may earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$0 - $400

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Medium Confidence400 reportsLast reported by owners Nov 2025Reviewed Mar 2026

Frequently Asked Questions

What are the most common Mercedes-Benz GLB problems?

According to Au7o's analysis of 1,800+ owner reports, the 2020-2025 Mercedes-Benz GLB has 10 documented issues. The most frequently reported are: Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246), Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990), ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679). Of these, 4 are rated critical and should be addressed promptly.

Is the Mercedes-Benz GLB reliable?

The 2020-2025 Mercedes-Benz GLB has 10 known issues documented across 1,800+ owner reports. 4 issues are rated critical: Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246) and Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990) and 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). 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 $6,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246), typically costs $0-$0 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What year Mercedes-Benz GLB is the most reliable?

Reliability varies across model years of the Mercedes-Benz GLB. Based on documented issues, problems are most commonly reported in earlier model years. Au7o recommends checking the specific known issues for your target year before purchasing, and having a pre-purchase inspection performed by a qualified mechanic. Our known issues database covers the 2020-2025 Mercedes-Benz GLB with 10 documented issues documented across 1,800+ owner reports.

All 10 Known Issues

2020 Mercedes-Benz GLB: Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246)#

Common Symptoms

How to Fix

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2020-2021 Mercedes-Benz GLB: Rearview Camera Fails to Display (Black Screen) Due to Software Error (Recall 22V232)#

Common Symptoms

How to Fix

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2020-2025 Mercedes-Benz GLB: MBUX Infotainment Freeze#

Common Symptoms

How to Fix

What you need to fix it

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2020-2022 Mercedes-Benz GLB: M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss)#

Common Symptoms

How to Fix

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2020-2024 Mercedes-Benz GLB: Carbon Buildup on Intake Valves (Direct-Injection M260) Causing Rough Idle and Power Loss#

Common Symptoms

How to Fix

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2020 Mercedes-Benz GLB: Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990)#

Common Symptoms

How to Fix

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2021 Mercedes-Benz GLB: ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679)#

Common Symptoms

How to Fix

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2020-2025 Mercedes-Benz GLB: 8G-DCT Transmission Shudder#

Common Symptoms

How to Fix

What you need to fix it

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2020-2022 Mercedes-Benz GLB: Emergency Call (eCall) System Disabled by Communication Module SIM Software Error (Recall 22V365)#

Common Symptoms

How to Fix

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2020-2025 Mercedes-Benz GLB: Panoramic Sunroof Creak#

Common Symptoms

How to Fix

What you need to fix it

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Frequently Asked Questions

What are the most common Mercedes-Benz GLB problems?

Is the Mercedes-Benz GLB reliable?

How much does it cost to fix common Mercedes-Benz GLB problems?

What year Mercedes-Benz GLB is the most reliable?

What is the 2020 Mercedes-Benz GLB Water Intrusion Into Front Footwells Causing Blank Instrument Cluster or Engine Stall (Recall 20V246)?

What is the 2020 Mercedes-Benz GLB Front Axle Carrier (Integral Carrier) Corrosion / Failure (Recall 21V990)?

What is the 2021 Mercedes-Benz GLB ESP/ABS Control Unit Damage Disabling Stability Control and Anti-Lock Brakes (Recall 22V679)?

What is the 2020-2022 Mercedes-Benz GLB M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss)?

What is the 2020-2025 Mercedes-Benz GLB 8G-DCT Transmission Shudder?

What is the 2020-2022 Mercedes-Benz GLB Emergency Call (eCall) System Disabled by Communication Module SIM Software Error (Recall 22V365)?

What is the 2020-2024 Mercedes-Benz GLB Carbon Buildup on Intake Valves (Direct-Injection M260) Causing Rough Idle and Power Loss?

What is the 2020-2021 Mercedes-Benz GLB Rearview Camera Fails to Display (Black Screen) Due to Software Error (Recall 22V232)?

What is the 2020-2025 Mercedes-Benz GLB MBUX Infotainment Freeze?

What is the 2020-2025 Mercedes-Benz GLB Panoramic Sunroof Creak?