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Mercedes-Benz · Known Issues

2025 Mercedes-Benz GLB Problems: 5 Known Issues

2025 model year · 1,800+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 1,800+ owner reports, the 2025 Mercedes-Benz GLB has 5 documented known issues. None of the listed issues is rated critical; this is not a complete reliability assessment. 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.

In This Article

  • GLB Electrical2
  • GLB Transmission1
  • GLB Body/Panels1
  • GLB Brakes1
  • FAQ
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In This Article

  • Electrical2
  • Transmission1
  • Body/Panels1
  • Brakes1
  • FAQ

All 5 Known Issues

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On the 2024-2026 Mercedes-Benz GLB M260 with 48V RSG mild hybrid, 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. When the 48V system fails to hand off correctly the 12V side carries loads it was never sized for, which is why the visible symptom is a flat 12V battery rather than a hybrid warning. Separately, GLB owners across model years report the small 1.2 Ah auxiliary battery plus short-trip driving leaves the 12V battery chronically undercharged.

This issue also affects: Mercedes-Benz EQE, Mercedes-Benz EQS, Mercedes-Benz EQS SUV

Common Symptoms

  • 12V battery flat after the car sits a few days
  • Repeated jump starts needed
  • Electrical system warning messages on startup
  • Stop/start and coasting functions unavailable
  • Car needs more frequent driving than normal to stay charged

How to Fix

Have the dealer check the VIN against service campaign 2025100004 and flash the updated 48V battery control software - it is a free software update, not a battery replacement. If discharge continues afterward, have a proper parasitic-draw test performed with the vehicle fully asleep (Mercedes modules can take 20-40 minutes to shut down, so a quick draw test gives a false result). Replace the 12V battery only after the campaign and the draw test, and always register/code the new battery with Xentry - an unregistered battery is undercharged by the charging strategy and will fail again. A CTEK-type maintainer is a reasonable stopgap for garage-kept cars.

Typical repair cost:$0 - $600

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
Medium ConfidenceVerifiedReviewed Aug 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.

Owner tips & cautions

  • TipSwitch from wireless to wired CarPlay/Android Auto. The wireless protocol causes more MBUX crashes. A simple USB cable solves most freeze issues.
Typical repair cost:$0 - $1,500

Research This Issue

Based on 600 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence600 owner reportsLast reported by owners Dec 2025Reviewed Mar 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

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Genuine Mercedes-Benz 724.1 eight-speed DCT service kit
    OEMFCP/Genuine Mercedes 724.1 DCT service kit

    VIN-confirmed 724.1 GLB250 fluid and filter maintenance branch Fitment/availability: The inspected direct U.S. Confirm VIN, transmission code, fluid specification and included quantitie

    FCP Euro

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • 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.
Typical repair cost:$150 - $2,500

Research This Issue

Based on 800 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence800 owner reportsLast reported by owners Nov 2025Reviewed Mar 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

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Genuine Mercedes-Benz sunroof lubricating paste 0019894651, half-ounce repack
    OEMMercedes-Benz 0019894651

    Small-quantity genuine paste for a confirmed service point that specifies this material Fitment/availability: The inspected direct U.S.

    ECS Tuning

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Owner tips & cautions

  • 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.
Typical repair cost:$0 - $400

Research This Issue

Based on 400 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence400 owner reportsLast reported by owners Nov 2025Reviewed Mar 2026

On the 2021-2025 Mercedes-Benz GLB M260 AMG, 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 the pad contact geometry sets up a resonance at low speed and low pedal effort. Mercedes-Benz has issued a technical service bulletin covering squeaky 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.

Common Symptoms

  • Loud squeal from the brakes in the last few mph of a light stop
  • Noise present from new and continuing after break-in
  • Noise absent under hard braking
  • Dealer initially calls the noise normal
  • Rear rotor surface rust and early rotor replacement on GLB250

How to Fix

Ask the dealer specifically for the GLA35/GLB35 squeaky-brake TSB rather than reporting it as a generic noise complaint. The remedy is replacement of the pads with the updated set followed by the prescribed bed-in drive per the bulletin - owners report this eliminating the squeal where cleaning, resurfacing, and shim/grease attempts did not. It is warranty work on in-warranty cars; out of warranty, a front pad set plus proper bed-in runs a few hundred dollars.

Typical repair cost:$0 - $600

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
Low ConfidenceVerifiedReviewed Aug 2026
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Other Mercedes-Benz Models

Mercedes-Benz GLE24Mercedes-Benz E-Class23Mercedes-Benz GLS23Mercedes-Benz Sprinter22Mercedes-Benz A-Class22Mercedes-Benz GLC22

Frequently Asked Questions

What are the most common Mercedes-Benz GLB problems?

According to Au7o's analysis of 1,800+ owner reports, the 2025 Mercedes-Benz GLB has 5 documented issues. The most frequently reported are: 8G-DCT Transmission Shudder, 48-Volt Lithium-Ion Battery Reinitialization Communication Fault Draining the 12V Battery (Service Campaign 2025100004), MBUX Infotainment Freeze. None are rated critical, but regular maintenance is recommended.

Is the Mercedes-Benz GLB reliable?

The 2025 Mercedes-Benz GLB has 5 known issues documented across 1,800+ owner reports. None of the matching records is rated critical; this is not a complete reliability assessment. 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 $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.

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

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.

What is the 2024-2026 Mercedes-Benz GLB 48-Volt Lithium-Ion Battery Reinitialization Communication Fault Draining the 12V Battery (Service Campaign 2025100004)?

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… Repairs typically run $0-$600. Severity: medium.

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

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.

Data sourced from 1,800+ owner reports, NHTSA recalls, TSBs, and automotive forums.

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.

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

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.

What is the 2021-2025 Mercedes-Benz GLB AMG GLB35 Front Brake Squeal Under Light Braking (TSB Pad Replacement and Bed-In)?

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.