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2020 Mercedes-Benz GLS-Class problems, recalls and owner complaints
What the 2020 Mercedes-Benz GLS-Class has been recalled for, how often it fails the UK MOT and what owners report, from official government data. Updated October 25, 2026.
- 0safety recalls
- 38owner complaints
- 3crash reports
- 1fire report
- 11%fail the UK MOT
38 complaints, against an average of 23 for the other 8 Mercedes-Benz GLS-Class model years.
Every Mercedes-Benz GLS-Class model year with its number of owner complaints. Pick a year to compare.
What goes wrong with the 2020 Mercedes-Benz GLS-Class?
The components named most often in the 38 owner complaints. One complaint can name several, so the shares can add up to more than 100%.
What symptoms do 2020 Mercedes-Benz GLS-Class owners describe?
Found by reading the text of all 38 owner complaints. Tap a symptom for the answer, a real owner quote and any related recall.
Has the 2020 Mercedes-Benz GLS-Class been recalled?
NHTSA lists no safety recalls for the 2020 Mercedes-Benz GLS-Class as of October 25, 2026. Recalls can be issued at any time, so check your VIN before you rely on this.
Is the 2020 Mercedes-Benz GLS-Class recalled in the UK or Europe?
Recalls issued by the UK's DVSA and through the EU's Safety Gate system that cover this model and build period. European models can differ from U.S. ones, and "years estimated" means the recall gave no build dates, so confirm your own car with your registration or VIN.
UK DVSASRPC2405 - Bolting of 48V ground connectionBolting of 48V ground connection
Risk: On affected vehicles the 48V ground connection under the passenger seat might have come loose.
Fix: Check the bolting of the ground connection and correct it if necessary.
UK DVSASRPC 2402 - Downshift operation transmission software
Risk: On certain vehicles the software of the transmission control unit might not meet specifications.
Fix: Update the transmission control unit software on the affected vehicles.
UK DVSAMercedes-Benz AG has determined that on certain GLE and GLS vehicles (167 platform) the air conditioning drain hoses might be incorrectly…Mercedes-Benz AG has determined that on certain GLE and GLS vehicles (167 platform) the air conditioning drain hoses might be incorrectly fitted in the vehicle. In this case condensation water from the air conditioning might enter the passenger compartment.
Risk: On certain vehicles the air conditioning drain hoses might be incorrectly fitted in the vehicle.
Fix: Check the air conditioning drain hoses and correct their installation if necessary.
UK DVSAInstallation of A/C drain hoses
Risk: On certain vehicles the air conditioning drain hoses might be incorrectly fitted in the vehicle.
Fix: Check the air conditioning drain hoses and correct their installation if necessary.
UK DVSAThe springs in the locking mechanism of the seat backrest of the third seat row may not have been installed in accordance with the…THE SPRINGS IN THE LOCKING MECHANISM OF THE SEAT BACKREST OF THE THIRD SEAT ROW MAY NOT HAVE BEEN INSTALLED IN ACCORDANCE WITH THE SPECIFICATIONS
Risk: The springs in the locking mechanism of the seat backrest of the third seat row may not have been installed in accordance with the specifications.
Fix: Check the springs in the seat backrest of the 3rd seat row on the affected vehicles and replace the seat backrest if necessary.
UK DVSAThe fixation of the trim bar at the rear door windows might not meet specifications
Risk: The fixation of the trim bar at the rear door windows might not meet specifications.
Fix: Check the fixation of the trim bars on the rear door windows and rework them if necessary.
UK DVSAThe bolting of a 12v power supply line might be fastened with an insufficient torque
Risk: The bolting of a 12V power supply line might be fastened with an insufficient torque.
Fix: Check the bolting of the wiring harness for correct torque and correct it if necessary. Additionally the contact area will be checked for potentially existing damages and if necessary the affected electrical lines and the contact module will be replaced.
UK DVSAThe bolting of the 48v ground connection under the passenger seat might be fastened with an insufficient torque
Risk: The bolting of the 48V ground connection under the passenger seat might be fastened with an insufficient torque.
Fix: Check the bolting of the ground connection on the affected vehicles and correct it if necessary.
UK DVSAThe software of the engine control unit might not meet specifications
Risk: On certain vehicles the software of the engine control unit might not meet specifications.
Fix: Conduct an update the software of the engine control unit on the affected vehicles.
UK DVSACoolant pump might have a leakage between the vacuum system and the coolant circuit
Risk: On certain vehicles with a Diesel engine the coolant pump which is controlled by vacuum might have a leakage between the vacuum system and the coolant circuit.
Fix: Update the software of the coolant pump and replace the electrical switch valve on the affected vehicles.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe seat assembly condition might not meet specifications
Risk: On certain vehicles the seat assembly condition might not meet specifications
Fix: Conduct a check of the seats on the affected vehicles and rework them if necessary
UK DVSAThe air conditioning drain hoses might be incorrectly fitted in the vehicle
Risk: The air conditioning drain hoses might be incorrectly fitted in the vehicle.
Fix: Conduct a check of the air conditioning drain hoses and correct their installation if necessary.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe behaviour of the emergency call system might not meet specifications
Risk: The behaviour of the emergency call system might not meet specifications.
Fix: Update the software of the communication module for the emergency call system.
UK DVSAThe communication module may be deactivated
Risk: The communication module may be deactivated
Fix: Carry out a check of the configuration of the communication module on affected vehicles and if necessary activate the communication module.
UK DVSAThe dashboard might not meet the specifications
Risk: The dashboard might not meet specifications
Fix: Replace the dashboard on the affected vehicles.
UK DVSAThe high voltage wiring harness shield may not permanently withstand the electrical loads that are induced under certain driving profiles
Risk: The shield for the high-voltage wiring harness may not permanently withstand the electrical loads that are induced under certain driving profiles
Fix: Replace the high-voltage wiring harness on the affected vehicles
UK DVSAThe fixation of the rear door windows trim bar may not meet specification
Risk: The fixation of the trim bar at the rear door windows might not meet specification.
Fix: Check the fixation of the trim bars on the rear door windows and rework them if necessary.
EU Safety GateThe 48V ground connection under the passenger seat may have become detached in the assembly process.This can increase electrical transition resistance at the point of connection. This can lead to an overheated ground connection and create a risk of fire.
Measures: Type of economic operator taking notified measure(s): Other; Category of measure(s): other; Date of entry into force: Unknown
EU Safety GateThe air conditioner may be faulty, which can lead to short circuits and/or fire.The automatic emergency call (eCall) may fail and the vehicle may not unlock and/or start. The emergency engine operation mode can be activated while driving. These errors create risks of injury.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe locking mechanism of the third row of seats may malfunction, which increases the risk of injury in the event of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateDue to a defect in the high fuel pressure manifold the engine might be damaged.This may lead to reduced engine power and to inability to start the vehicle, increasing the risk of an accident.
Measures: Type of economic operator taking notified measure(s): Importer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe bolt for the 48V ground connection under the passenger seat may have been secured with insufficient torque.As a result, the electrical resistance of the connection could increase and the temperature may therefore rise in this area, posing a risk of fire.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe vacuum-controlled coolant pump may not be tightly sealed between the coolant and vacuum circuits.This may result in the coolant leaking into the vacuum circuit leading to an electrochemical reaction, increasing the risk of fire.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateA trapped particle may damage the sealing between the fuel rail and fuel injector, which could cause fuel to leak into the engine…A trapped particle may damage the sealing between the fuel rail and fuel injector, which could cause fuel to leak into the engine compartment. Consequently, leaking fuel may come into contact with hot parts of the engine, increasing the risk of fire.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateIn certain GLE/GLS (BR 167) and C-class vehicles, the seats might be constructed incomplete or with unintended trim, increasing the risk…In certain GLE/GLS (BR 167) and C-class vehicles, the seats might be constructed incomplete or with unintended trim, increasing the risk of injury in the event of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe condensed water drainage hose of the air-conditioning system may not be properly fitted and could spontaneously detach.Consequently, condensation water could enter the passenger compartment and corrode electrical components, which could lead to short-circuits increasing the risk of fire. Additionally, this corrosion might cause different electrical systems to malfunction, increasing the risk of accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe surface of the instrument panel might not be adequately bonded to the base support.As a result, the opening behaviour of the passenger airbag could be impaired, increasing the risk of injury in the event of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe ESP control unit software does not comply with the specifications and may not be able to adapt to the type of brakes installed.This can cause the ESP system to be unable to respond as intended to a possible drift of the yaw rate sensor or to a failure of the brake vacuum supply. As a result, the ESP intervention may be inappropriate to the driving situation, increasing the risk of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe piston bar seal on the shock absorbers does not meet the durability requirements.This can result in tilting of the vehicle with full load when cornering, increasing the risk of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe welds on the rear cross-beam may not be sufficiently strong and could break.As a result, the cross-beam may become detached from the vehicle during a towing operation, increasing the risk of an accident.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
EU Safety GateThe garnish moulding to the window stay bar of the rear doors may not be installed correctly.As a result, the garnish moulding could become detached in motion, posing a risk to the following traffic.
Measures: Type of economic operator taking notified measure(s): Manufacturer; Category of measure(s): Recall of the product from end users; Date of entry into force: Unknown
How often does the 2020 Mercedes-Benz GLS-Class fail its MOT?
Why they failed: the share of failed tests with at least one fault in each area (a test can fail on several). Cars first registered in 2020, tested in Great Britain in 2023; first registration is usually, but not always, the model year. Source: DVSA anonymised MOT tests and results, Open Government Licence v3.0.
What do 2020 Mercedes-Benz GLS-Class owners report?
12 of the 38 complaints, the most recent for the most-reported components, as the owners wrote them. NHTSA removes names and VINs; long reports are trimmed. CarHooq has not verified individual claims.
AMENDMENT TO ACTIVE CASE 11723015. CRITICAL AIRBAG & SAFETY DEFECTS. This files a safety defect amendment to open case 11723015. Diagnostic scans confirm central data bus network collapse on VIN [XXX] has migrated into safety-critical occupant restraint and visibility modules, violating 49 U.S.C. § 30118. I. AIRBAG & RESTRAINT HAZARDS Scans from [XXX], document active faults: DTC U042782: "Implausible data received from Electronic Ignition Lock." The SRS module receives corrupted data from the failed ignition gateway, creating risk of airbag non-deployment. DTC B007A13: Passenger seatbelt…
The engine wiring harness insulation near the ignition coil connectors prematurely deteriorated due to prolonged exposure to engine heat in the turbocharger/exhaust area. Multiple wiring connectors exhibited brittle, cracked insulation with exposed conductors. The degraded wiring began shorting within the ignition system, causing engine misfires, ignition circuit faults, and eventual loss of engine operation. While being operated by a rental customer the vehicle developed severe misfires followed by electrical shorting, smoke, localized flames in the engine harness area, and eventual engine…
On a sunny afternoon without zero clouds in the sky, 75 degrees I was driving at 35 mph on a two-lane road with no cars in front of me, behind me, or coming in the other direction, the brakes were urgently and automatically applied and the seat belts dramatically tightened. The system showed a large red X on the screen. It was obvious the automated safety system mistakenly thought we were about to crash into something but there wasn't anything but smooth asphalt.
The vehicle (2020 GLS 450) suffers from terminal infrastructure "Electronic Rot," resulting in a consistent Breach of FMVSS 111 (Rearview Visibility) and dangerous Automatic Emergency Braking hallucinations. On 03/08/2026, a routine car wash triggered multiple system failures, including "Camera View Restricted" and "Adaptive Highbeam Assist Currently Unavailable," proving the electrical architecture is compromised by minor moisture. This is a multi-dealer failure: the vehicle was sold as "Certified Pre-Owned" by Mercedes-Benz of Fredericksburg with undisclosed active "Special Procurement"…
The vehicle is experiencing deterioration of the main engine wiring harness insulation, resulting in exposed wires contacting each other. This condition has caused intermittent check engine lights and electrical fault codes. The dealership has confirmed that the wiring insulation has degraded, allowing wires to contact each other. The issue appears related to material durability of the harness rather than external damage. The concern is that continued deterioration could result in: •Sudden engine misfire •Loss of power while driving •Engine stalling •Potential electrical short circuit An…
The fuel rail system failed on the passenger side of the engine and leaks. This is the same issue seen on, but VIN number isn't apart of it: Campaign No. : 2022030003 CA DMV. : 220303 NHTSA ID 21V961 I have taken the vehicle to a Mercedes dealer twice for the concern of smelling gas. The second time I had a video but the service tech couldn't replicate the leak. This safety concern pose a great risk as the gas could come into contact with a hot surface and ignite but passenger at HIGH risk. The problem has taken to the dealer twice with video showing the leak., however they cannot reproduced…
On numerous occasions the transmission does not fully down shift to the next lower gear and then when I have to accelerate quickly it will drop down to the lower gear like it’s supposed to but won’t shift out to the next higher gear and when I let my foot off the accelerator the truck slows down quickly like applying the brakes which almost had me rear ended a few times and now the adaptive cruise control is malfunctioning
I am writing to escalate an unresolved service issue with my 2020 Mercedes Benz GLS 450, VIN [XXX] . During a maintenance service on March 6, my trusted independent services shop for 25 years, Carrera Motors in San Mateo CA, identified that the electrical harness of my GLS 450 was significantly damaged. The plastic casing around the wires had effectively disintegrated, exposing the wires directly to the engine. Carrera Motors indicated that this was a serious issue and does not normally occur with a 5 year old vehicle. They encouraged me to contact Mercedes directly. At the instruction of…
The adaptive cruise control feature of this vehicle on various highways [XXX] , [XXX] and the [XXX] ) and in various locations while traveling at highway speeds has mis-read speed limit signs and aggressively decelerated(I assume by using its regenerative braking) to as low as 35mph while traffic is moving at 65+mph. The dealership was unable to duplicate this issue. No faults are displayed to the driver. I do not know if rear brake lights are illuminated when this occurs. This is an aggressive and scary deceleration with no warning. I fear a rear end collision is likely. No one aside from the…
The passenger rear wheel brake caliper lower bolt got loose. The bolt is most likely not available for inspection. The caliper body then started rubbing against the wheel inside surface and caused a noise. If the caliper body had jammed into the wheel and stopped it from rotating, say on the highway, the vehicle could have skidded or rolled over? The MB dealership inspected and replaced the bolt. There were no warning lamps, messages or other symptoms of the problem prior to the failure. The noise came during braking on tuesday, 28 May. The car was repaired by the MB dealership on Thursday, 30…
03/17/2023 driving on US1 coming up to speed after pulling onto highway after cars passed I went 0.2 miles and was looking at my driver side mirror ( no traffic on road ahead of me) when I hit something that pushed my big SUV toward oncoming traffic. I held wheel and muscled car to side of road stopping short of a telephone pole. Car was upright I had trouble loosening seat belt while my wife was hanging forward into hers. Dog harnessed in back seat was ok Got out of car to see a car hauler 30? Footer sticking about 4 feet into the road and travel lane. Investigation by police revealed truck…
On numerous occasions, when either slowing down or in a slow turn, the engine dies and will not reengage until I have turned off the vehicle, exited, then reentered an started the vehicle. I have had passengers in the vehicle who will attest to this occurring, in fact, the last time it happened, I was almost broadsided when the vehicle stopped in the middle of a left-hand turn, crossing three lanes of oncoming traffic. The vehicle has been to the dealership at least three times and it's either a "software update" requirement or "we can't duplicate" the issue. When I called MB Customer Service…
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2020 Mercedes-Benz GLS-Class: questions owners ask
Is the 2020 Mercedes-Benz GLS-Class reliable?
NHTSA data alone cannot rate reliability, but it shows what owners reported. Owners filed 38 complaints with NHTSA about the 2020 Mercedes-Benz GLS-Class; the most common categories were electrical system (18, 47.4%), engine (9, 23.7%), fuel/propulsion system (8, 21.1%). There are no safety recalls listed for this model year. 3 complaints mention a crash, 1 mentions a fire, 3 injuries were reported.
What are the most common problems with the 2020 Mercedes-Benz GLS-Class?
Across 38 owner complaints filed with NHTSA, the categories mentioned most often are electrical system (47.4% of complaints), engine (23.7% of complaints), fuel/propulsion system (21.1% of complaints), forward collision avoidance (18.4% of complaints), power train (10.5% of complaints). One complaint can name several components.
Does the 2020 Mercedes-Benz GLS-Class have any recalls?
As of October 2026, NHTSA lists no safety recalls for the 2020 Mercedes-Benz GLS-Class. Recalls can be issued at any time, so check your VIN at nhtsa.gov/recalls.
Why does my 2020 Mercedes-Benz GLS-Class stall, lose power or shut off while driving?
6 of the 38 owner complaints NHTSA has on file for the 2020 Mercedes-Benz GLS-Class (15.8%) describe the engine stalling, losing power or shutting off while driving. One owner wrote: "The vehicle warnign system displayed "48v Malfunction." Vehicke lost all acceleration in the middle of the highway. The vehicle was just returned3 days ago after undergoing a state inspection at the MB dealership." (NHTSA complaint 11439135, November 2021). If it happens to your car, check your VIN for open recalls at nhtsa.gov/recalls and report the problem to NHTSA; complaints are what trigger investigations.
Why is the check engine light on in my 2020 Mercedes-Benz GLS-Class?
4 of the 38 owner complaints NHTSA has on file for the 2020 Mercedes-Benz GLS-Class (10.5%) describe the check engine light coming on. One owner wrote: "This incident occurred around 5:50pm on Wednesday, September 21, 2022. I was driving on a merge connector between two freeways in San Francisco at about 60mph, when the vehicle threw a series of error codes and warnings on its displays, culminating with “shut…" (NHTSA complaint 11486139, September 2022). If it happens to your car, check your VIN for open recalls at nhtsa.gov/recalls and report the problem to NHTSA; complaints are what trigger investigations.
Why does my 2020 Mercedes-Benz GLS-Class overheat?
3 of the 38 owner complaints NHTSA has on file for the 2020 Mercedes-Benz GLS-Class (7.9%) describe the engine overheating or coolant loss. One owner wrote: "On a long road trip - about halfway on [XXX] - received an error message on 48v system malfunction - immediately called nearest Mercedes dealership (Richmond Va) to schedule a service - while on the line received an engine overheating pull over and shut it…" (NHTSA complaint 11639933, January 2025). If it happens to your car, check your VIN for open recalls at nhtsa.gov/recalls and report the problem to NHTSA; complaints are what trigger investigations.
Check your own GLS-Class
Counts are a starting point, not a verdict: popular models collect more complaints because more of them are on the road, and NHTSA does not verify individual reports. To see whether a recall is still open on your car, enter your VIN at nhtsa.gov/recalls (U.S.) or your registration at check-vehicle-recalls.service.gov.uk (UK). Had a safety problem? Report it to NHTSA; complaints are what trigger investigations and recalls.
Data: NHTSA Office of Defects Investigation recall and complaint databases (public domain), DVSA anonymised MOT results (Open Government Licence v3.0), DVSA vehicle recalls (Open Government Licence v3.0), EU Safety Gate alerts (© European Union), retrieved October 25, 2026. Model year 2020 only.