What are the most common Mercedes-Benz GLS problems?
According to Au7o's analysis of 3,550+ owner reports, the 2017-2025 Mercedes-Benz GLS has 11 documented issues. The most frequently reported are: AIRMATIC Air Suspension Failure, 48V Ground Connection Overheating and Fire Risk (Recall 24V207), Engine Stall from Transmission Control Unit Software (Recall 24V118). Of these, 4 are rated critical and should be addressed promptly.
Is the Mercedes-Benz GLS reliable?
The 2017-2025 Mercedes-Benz GLS has 11 known issues documented across 3,550+ owner reports. 4 issues are rated critical: AIRMATIC Air Suspension Failure and 48V Ground Connection Overheating and Fire Risk (Recall 24V207) and Engine Stall from Transmission Control Unit Software (Recall 24V118) and 4MATIC Transfer Case Bearing Wear, Whine and Drivetrain Lock-Up Risk. 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, AIRMATIC Air Suspension Failure, typically costs $800-$4,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What year Mercedes-Benz GLS is the most reliable?
Reliability varies across model years of the Mercedes-Benz GLS. 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 2017-2025 Mercedes-Benz GLS with 11 documented issues documented across 3,550+ owner reports.
What is the 2017-2023 Mercedes-Benz GLS AIRMATIC Air Suspension Failure?
The GLS AIRMATIC system is prone to air spring leaks and compressor failure due to the vehicle's heavy curb weight (5,700+ lbs). Front air springs tend to fail first. The compressor overworks to maintain ride height and eventually burns out. Repairs typically run $800-$4,000. Severity: high.
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 2020-2023 Mercedes-Benz GLS Engine Stall from Transmission Control Unit Software (Recall 24V118)?
Certain X167 GLS 450 (and V167 GLE 450) vehicles left the factory with transmission control unit (TCU) software that does not meet current specifications. If a downshift of the 9G-Tronic from 7th to 6th gear is not fully completed during a light braking maneuver, and several cond… 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 2017-2023 Mercedes-Benz GLS 9G-Tronic Harsh Shift?
The 9G-Tronic nine-speed automatic exhibits harsh low-speed shifts and hunting between gears on inclines. The transmission software struggles to select the optimal gear among nine ratios, particularly noticeable in stop-and-go traffic. Repairs typically run $150-$2,500. Severity: medium.
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 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 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 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.
