Au7o mascotAu7o
Known IssuesTest Hub demo
  1. Au7o
  2. /
  3. Known Issues
  4. /
  5. Mercedes-Benz
  6. /
  7. GLS
Mercedes-Benz · Known Issues

2024 Mercedes-Benz GLS Problems: 9 Known Issues

2024 model year · 950+ owner reports · Updated September 2026

Share:@au7o.io

2024 · All trims · All engines

Choose the year and equipment for your written issues and visual request.

Known IssuesMotorcycle IssuesDTC LookupDrivePricingAboutTermsPrivacyCookiesConsentData rightsCopyrightFeedback
Share:@au7o.io

Vehicle data and repair guidance on this site are compiled with AI assistance and may contain errors. Always verify with your service manual or a qualified mechanic.

Data protection representation

DataRep representative in the United KingdomDataRep representative in the European Union
Au7o · 2026
Built for DIY mechanics. Privacy-first.
Explore free Hub demo
No email neededHow interest is saved

Interest applies to the selected vehicle and configuration; it is not a reservation. Voting stores a first-party identifier for up to 180 days to prevent repeat votes. No account or email is needed. Clearing cookies or using another device may count separately. Privacy

Visual coming soon

Your interest helps us choose what to build next.

Visual Known Issues · Coming soon

$4.99/month plus taxes at launch · No payment today

Preview the XT6 example
Issue summary

According to Au7o's analysis of 950+ owner reports, the 2024 Mercedes-Benz GLS has 9 documented known issues, with 3 rated critical. The most serious are 48V Ground Connection Overheating and Fire Risk (Recall 24V207) ($0-$0 repair), 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk ($2,500-$7,000 repair) and Fuel Pump Impeller Deformation Causing Pump Shutdown and Loss of Drive Power (Recalls 23V445 / 23V880) ($0-$1,800 repair). The most commonly reported issue is Panoramic Sunroof Water Leak with 500 owner reports. Across all issues with published estimates, repair costs range from $100 to $9,000. DIY maintenance guides at au7o.io.

In This Article

  • GLS Electrical3
  • GLS Fuel System2
  • GLS Drivetrain1
  • GLS Body/Panels1
  • GLS Engine1
  • GLS Emissions1
  • FAQ
Get Started
Back to top

In This Article

  • Electrical3
  • Fuel System2
  • Drivetrain1
  • Body/Panels1
Engine
1
  • Emissions1
  • FAQ
  • All 9 Known Issues

    Filter:
    ALL YEARS202520242023202220212020201920182017

    On the 2020-2024 Mercedes-Benz GLS, on 48V mild-hybrid GLS 450/580 models, the ground cable bolt for the 48V system located under the front passenger seat may not have been tightened to specification at the factory. A loose ground lug increases electrical resistance which, combined with the very high currents the 48V starter-alternator (ISG) draws, can cause the connection to overheat, melt surrounding components and, in the worst case, start a fire. This prompted a U.S. safety recall (NHTSA 24V207) covering roughly 116,020 GLE and GLS vehicles built between June 2017 and January 2023. This is a physical hardware/connection defect distinct from a discharged 48V battery — the connection itself overheats.

    Common Symptoms

    • Burning or electrical smell from front passenger floor area
    • Repeated 48V system / electrical fault warnings
    • Melted or discolored connection under passenger seat
    • Potential fire / smoke

    How to Fix

    Have the dealer perform recall 24V207: inspect and re-torque (and if necessary replace) the 48V ground connection under the front passenger seat, free of charge. Owners who notice a burning/electrical smell from the front-passenger floor area, repeated 48V system faults, or warning messages should stop driving and contact Mercedes. Check VIN against the recall at the NHTSA or Mercedes recall lookup.

    Typical repair cost:$0 - $0

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceVerifiedReviewed Jun 2026
    Community reported
    450 owners

    On the 2020-2025 Mercedes-Benz GLS, the 48V EQ Boost mild hybrid system causes excessive battery drain when parked. A software bug in the 48V battery management module fails to properly enter sleep mode, draining both the 48V lithium-ion and 12V lead-acid batteries.

    This issue also affects: Mercedes-Benz C-Class, Mercedes-Benz CLS-Class, Mercedes-Benz E-Class

    Common Symptoms

    • Dead battery after sitting for 3-5 days
    • Multiple electrical warnings on startup

    How to Fix

    Update the 48V battery management software at the dealer. If both batteries are deeply discharged, they may need replacement. The 12V battery is $200-400, the 48V battery is $1,500-3,000.

    Owner tips & cautions

    • TipIf the GLS sits for more than a week, connect a battery tender to the 12V battery under the hood. The 48V system draws from the 12V to maintain its state of charge.
    Typical repair cost:$200 - $3,500

    Research This Issue

    Based on 450 owner reports

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium Confidence450 owner reportsLast reported by owners Dec 2025Reviewed Mar 2026

    On the 2020-2025 Mercedes-Benz GLS, gLS X167 owners report the MBUX infotainment system freezing, showing a black or flickering screen, distorted display, unresponsive touch controls, or randomly rebooting. The faults are intermittent and often software-related, frequently triggered by or persisting through OTA/software updates. While usually not safety-critical, a frozen unit can disable navigation, climate controls and the central display, which is a notable annoyance in a vehicle at this price point.

    Common Symptoms

    • Frozen / unresponsive central display
    • Black or flickering screen
    • Random system reboots
    • Touchscreen not responding
    • Navigation/climate controls unavailable until restart

    How to Fix

    Perform a soft reset by pressing and holding the infotainment power/volume control for about 10 seconds to reboot the system. Ensure the latest software is installed via Settings > System > Software Update. If freezes are recurring, the dealer can update or factory-reset MBUX, and persistent hardware faults may require head-unit service under warranty.

    Typical repair cost:$0 - $600

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceVerifiedReviewed Jun 2026

    On the 2021-2024 Mercedes-Benz GLS, on 2021-2024 X167 GLS models (GLS 450, GLS 580, Maybach GLS 600 and AMG GLS 63), certain batches of the in-tank fuel delivery module were built with impellers whose plastic did not meet Mercedes' material specification. The impeller can swell and deform, drag against the pump housing, and in some cases stall the pump outright. Because the 48V mild-hybrid system cannot propel the vehicle on its own, a pump shutdown means an immediate loss of propulsion in traffic. Mercedes first recalled 2021-2023 vehicles under 23V-445 in mid-2023 and expanded the population to 2021-2024 under 23V-880 in December 2023 (~79,676 vehicles across GLE/GLS, C, E, S, SL, GLC, CLS, AMG GT and G-Class). The Part 573 report notes the driver may first see an instrument-cluster warning and rough running before the pump quits.

    Common Symptoms

    • Instrument-cluster fuel system or engine warning message
    • Engine running rough or stumbling before stalling
    • Sudden loss of propulsion while driving
    • No-start after pump shutdown

    How to Fix

    Free recall remedy: an authorized dealer replaces the entire fuel delivery module with one using impellers that meet the material requirement (remedy part numbers include A1674700394 / A1674704500 / A1674706900 for the 167 platform). Owner letters for 23V-880 went out in February 2024. Check the VIN at nhtsa.gov/recalls; if a 2021-2024 GLS shows rough running or a fuel-system warning, have the dealer confirm recall status before any other diagnosis. Out-of-recall pump replacement runs roughly $900-1,800.

    Find a Mercedes-Benz dealer

    Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

    Open Mercedes-Benz dealer map in Google Maps ↗

    Call to confirm they service Mercedes-Benz vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    Typical repair cost:$0 - $1,800

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceVerifiedReviewed Sep 2026

    On the 2020-2025 Mercedes-Benz GLS OM656 3.0L I6 diesel, the OM656 diesel uses a precise Bosch CP4 common-rail high-pressure fuel pump that reacts poorly to low-quality diesel or fuel contamination. Even minor tank impurities or a single mis-fueling event can damage the pump and injection nozzles, and metallic debris from a failing CP4 can circulate through the fuel system. Clogged fuel filters from contaminated fuel further disrupt combustion and cause power loss. Repairs can be extensive because a failed CP4 may require cleaning or replacing injectors, lines and the high-pressure pump. This is an EU-relevant concern given diesel availability and variable fuel quality across markets.

    This issue also affects: Mercedes-Benz AMG GT, Mercedes-Benz E-Class, Mercedes-Benz G-Class

    Common Symptoms

    • Hard starting or no-start
    • Rough running / misfire
    • Power loss
    • Fuel system warning light
    • Metal debris in fuel filter

    How to Fix

    Fuel only with high-quality diesel from reputable stations and never mis-fuel with petrol. Replace the fuel filter(s) on schedule. At the first sign of a hard start, rough running, or fuel-system warning, stop driving and have the fuel system inspected — catching CP4 wear early can avoid a full fuel-system contamination repair. If metallic debris is found, the pump, lines and injectors typically all require service.

    Typical repair cost:$1,500 - $8,000

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceVerifiedReviewed Jun 2026

    On the 2020-2025 Mercedes-Benz GLS, the 4MATIC transfer case on the GLS is prone to internal bearing wear, typically beginning with fluid degradation or a slow leak from the output/case seals. As the bearings wear, owners report a whining or grinding noise that increases with vehicle speed and worsens over time. On the X167 generation the transfer case is more closely integrated with the 9G-Tronic transmission, so a severe bearing failure can shed metal debris into the transmission, turning a contained repair into a much larger and more expensive one. In the worst case a complete failure can lock the drivetrain or cause sudden loss of drive. Running mismatched/uneven tires accelerates the wear.

    Common Symptoms

    • Whining noise that rises with speed
    • Grinding noise from drivetrain
    • Fluid leak under transfer case
    • Vibration or drivetrain bind
    • Sudden loss of power / drivetrain lock-up in severe cases

    How to Fix

    Service the transfer case fluid on a preventive interval (Mercedes does not list a fixed interval, but enthusiasts recommend roughly every 60,000 miles) and address any seal leak promptly to keep the fluid full. Investigate any speed-dependent whine early with a fluid inspection for metal particles. Always replace all four tires together with matching brand/size/wear to avoid driveline bind. A failed transfer case typically runs into the thousands, and far more if debris damages the transmission.

    Typical repair cost:$2,500 - $7,000

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium ConfidenceVerifiedReviewed Jun 2026
    Community reported
    500 owners

    On the 2020-2025 Mercedes-Benz GLS, the large panoramic sunroof on the X167 GLS develops water leaks at the drain tubes or seal interface. Water enters the headliner and can drip into the cabin, staining the headliner and potentially damaging the overhead electronics.

    Common Symptoms

    • Water dripping from overhead console area
    • Damp headliner after rain or car wash

    How to Fix

    Clear the sunroof drain tubes with compressed air. Reseal the sunroof glass to the frame if the weatherstrip has shifted. If the headliner is water-stained, it may need cleaning or replacement.

    Owner tips & cautions

    • TipAvoid automated car washes with high-pressure nozzles pointed at the roof. The extreme water pressure overwhelms the sunroof seals and drains. Hand wash or touchless wash only.
    Typical repair cost:$100 - $1,500

    Research This Issue

    Based on 500 owner reports

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium Confidence500 owner reportsLast reported by owners Nov 2025Reviewed Mar 2026

    On the 2020-2024 Mercedes-Benz GLS M256 3.0L I6 turbo, owners of GLS 450 models with the M256 3.0L turbocharged inline-six report elevated oil consumption that tends to surface at higher mileage (commonly reported around 60,000 miles / ~100,000 km). The pattern — oil disappearing without visible external leaks — points to internal piston ring / cylinder wear as the likely cause, and in some documented cases correcting it required significant engine disassembly. There is no factory recall specifically for piston rings/oil consumption on the M256 as of 2026, so repairs typically fall on the owner once out of warranty.

    Common Symptoms

    • Oil level dropping without visible leaks
    • Low oil warning between services
    • Blue smoke under load (advanced cases)
    • Frequent need to top up oil

    How to Fix

    Monitor oil level frequently between services and keep records of consumption rate to support a goodwill/warranty claim. Use only Mercedes-spec (MB 229.x) low-ash synthetic oil and avoid extended drain intervals. If consumption exceeds roughly 1 quart per 1,000 miles, have the dealer perform a documented oil-consumption test; persistent excessive consumption may require piston ring or short-block work.

    Typical repair cost:$3,000 - $9,000

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium ConfidenceVerifiedReviewed Jun 2026

    On the 2020-2025 Mercedes-Benz GLS OM656 3.0L I6 diesel, eU-market GLS 350d/400d models with the OM656 3.0L inline-six diesel suffer from sensitivity in the exhaust aftertreatment chain. The EGR (AGR) valve, diesel particulate filter (DPF) and SCR/AdBlue system are sensitive to poor fuel quality, short-trip driving and temperature swings. Clogged DPF, a dirty/sticking EGR valve, or a faulty EGR differential-pressure sensor cause power loss, failed regenerations, dashboard warnings and limp-home mode. A German motor-talk owner thread on the GLS X167 400d documents poor acceleration that resolves after a restart, traced to a replaced EGR differential-pressure sensor under warranty. This primarily affects diesels not sold in the US, so it is especially relevant to the EU market.

    This issue also affects: Mercedes-Benz B-Class, Mercedes-Benz E-Class, Mercedes-Benz GLA

    Common Symptoms

    • Reduced power / poor acceleration
    • Limp-home mode
    • DPF / exhaust warning light
    • Repeated regeneration cycles or failed regen
    • Increased fuel consumption
    • AdBlue/SCR warning

    How to Fix

    Drive the vehicle regularly at highway speed/load to allow active DPF regeneration to complete; avoid chronic short trips. Keep AdBlue topped up with spec-compliant fluid. Have a clogged DPF forced-regenerated or cleaned, and replace a sticking EGR valve or faulty EGR differential-pressure sensor as needed. Use good-quality diesel to reduce soot loading. Address fault codes promptly before forced regen damages the DPF.

    Typical repair cost:$300 - $2,500

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceVerifiedReviewed Jun 2026
    🔧
    A mechanic who knows YOUR exact car
    Answers tuned to your year, make, model & trim — not generic advice. Save your garage so it always has the right context.
    Get ahead of Mercedes-Benz GLS problems — free
    Leave your email and we'll alert you the moment there's a new recall or known issue for your Mercedes-Benz GLS. Free, no account needed.

    Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.

    Other Mercedes-Benz Models

    Mercedes-Benz GLE24Mercedes-Benz E-Class23Mercedes-Benz Sprinter22Mercedes-Benz A-Class22Mercedes-Benz GLC22Mercedes-Benz CLA21

    Frequently Asked Questions

    What are the most common Mercedes-Benz GLS problems?

    According to Au7o's analysis of 950+ owner reports, the 2024 Mercedes-Benz GLS has 9 documented issues. The most frequently reported are: 48V Ground Connection Overheating and Fire Risk (Recall 24V207), 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk, Fuel Pump Impeller Deformation Causing Pump Shutdown and Loss of Drive Power (Recalls 23V445 / 23V880). Of these, 3 are rated critical and should be addressed promptly.

    Is the Mercedes-Benz GLS reliable?

    The 2024 Mercedes-Benz GLS has 9 known issues documented across 950+ owner reports. 3 issues are rated critical: 48V Ground Connection Overheating and Fire Risk (Recall 24V207) and 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk and Fuel Pump Impeller Deformation Causing Pump Shutdown and Loss of Drive Power (Recalls 23V445 / 23V880). 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 GLS problems?

    Repair costs for known Mercedes-Benz GLS issues range from $0 to $9,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 48V Ground Connection Overheating and Fire Risk (Recall 24V207), typically costs $0-$0 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

    What is the 2020-2024 Mercedes-Benz GLS 48V Ground Connection Overheating and Fire Risk (Recall 24V207)?

    On 48V mild-hybrid GLS 450/580 models, the ground cable bolt for the 48V system located under the front passenger seat may not have been tightened to specification at the factory. A loose ground lug increases electrical resistance which, combined with the very high currents the 4… Repairs typically run $0-$0. Severity: high.

    What is the 2020-2025 Mercedes-Benz GLS 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk?

    The 4MATIC transfer case on the GLS is prone to internal bearing wear, typically beginning with fluid degradation or a slow leak from the output/case seals. As the bearings wear, owners report a whining or grinding noise that increases with vehicle speed and worsens over time. On… Repairs typically run $2,500-$7,000. Severity: high.

    What is the 2021-2024 Mercedes-Benz GLS Fuel Pump Impeller Deformation Causing Pump Shutdown and Loss of Drive Power (Recalls 23V445 / 23V880)?

    On 2021-2024 X167 GLS models (GLS 450, GLS 580, Maybach GLS 600 and AMG GLS 63), certain batches of the in-tank fuel delivery module were built with impellers whose plastic did not meet Mercedes' material specification. The impeller can swell and deform, drag against the pump hou… Repairs typically run $0-$1,800. Severity: high.

    What is the 2020-2025 Mercedes-Benz GLS Panoramic Sunroof Water Leak?

    The large panoramic sunroof on the X167 GLS develops water leaks at the drain tubes or seal interface. Water enters the headliner and can drip into the cabin, staining the headliner and potentially damaging the overhead electronics. Repairs typically run $100-$1,500. Severity: medium.

    What is the 2020-2025 Mercedes-Benz GLS Battery Drain from 48V System?

    The 48V EQ Boost mild hybrid system causes excessive battery drain when parked. A software bug in the 48V battery management module fails to properly enter sleep mode, draining both the 48V lithium-ion and 12V lead-acid batteries. Repairs typically run $200-$3,500. Severity: medium.

    What is the 2020-2025 Mercedes-Benz GLS OM656 Diesel CP4 High-Pressure Fuel Pump Sensitivity and Injector Damage?

    The OM656 diesel uses a precise Bosch CP4 common-rail high-pressure fuel pump that reacts poorly to low-quality diesel or fuel contamination. Even minor tank impurities or a single mis-fueling event can damage the pump and injection nozzles, and metallic debris from a failing CP4… Repairs typically run $1,500-$8,000. Severity: medium.

    What is the 2020-2024 Mercedes-Benz GLS M256 Engine Excessive Oil Consumption and Piston Ring Wear?

    Owners of GLS 450 models with the M256 3.0L turbocharged inline-six report elevated oil consumption that tends to surface at higher mileage (commonly reported around 60,000 miles / ~100,000 km). The pattern — oil disappearing without visible external leaks — points to internal pi… Repairs typically run $3,000-$9,000. Severity: medium.

    What is the 2020-2025 Mercedes-Benz GLS OM656 Diesel Emissions System Clogging (EGR/DPF/AdBlue SCR) and Limp Mode?

    EU-market GLS 350d/400d models with the OM656 3.0L inline-six diesel suffer from sensitivity in the exhaust aftertreatment chain. The EGR (AGR) valve, diesel particulate filter (DPF) and SCR/AdBlue system are sensitive to poor fuel quality, short-trip driving and temperature swin… Repairs typically run $300-$2,500. Severity: medium.

    What is the 2020-2025 Mercedes-Benz GLS MBUX Infotainment Freezing, Black Screen and Random Reboots?

    GLS X167 owners report the MBUX infotainment system freezing, showing a black or flickering screen, distorted display, unresponsive touch controls, or randomly rebooting. The faults are intermittent and often software-related, frequently triggered by or persisting through OTA/sof… 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.

    Data sourced from 950+ owner reports, NHTSA recalls, TSBs, and automotive forums.