2020 MERCEDES-BENZ GLS-Class Problems

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Complaints Reported

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Complaints by Component

ELECTRICAL SYSTEM

8 complaints

The vehicle, 2020 Mercedes-Benz GLS450, was being backed out of the garage when an electrical failure occurred causing the vehicle to malfunction. This was a major safety issue that caused the entire vehicle electrical control systems to fail as the vehicle would not turn-off. The vehicle eventually turned-off and was not operational. It was towed to a local dealer where we were they discovered that a heating/cooling system hose caused moisture to enter the cab of the vehicle. The end result was major electrical damage to the vehicle control system of the vehicle. This vehicle is my wife's primary means of travel along with our 4 young children. Had this major malfunction occurred while on a highway going at high speeds a parish the thought of what could have happened to the safety of my wife and children. Per attached dealership bill, the dealership was not able to obtain coverage for this $4,255.15 repair bill. In addition, I did find other Mercedes-Benz GLS450 models who were recalled for this very safety issue where moisture in the cab resulted in major electrical control systems of the vehicle.

Apr 29, 2025

While driving on the New Jersey Turnpike on November 17, 2023, a burning smell was noticed inside the car. The smell lasted about an hour. No smoke was present and the car continued to operate. While concerned, I assumed it was environmental and outside the car. On November 25, 2023 my car threw a 48V battery warning and forcibly shut off. We were not on a highway at the time and were able to pull over to a gas station. MB roadside was called and towed the car to Euro Motorcars Devon of Devon, PA, the local Mercedes-Benz dealer and where I purchased the car and receive service. Over the course of the next few weeks the service department concluded and ultimately determined that there were burnt out cables which were connected to the 48V battery (this is highlighted in the service receipt attached). This repair was not covered under my warranty and lead to a $5,804.56 repair bill. The car was repaired to my satisfaction and the bill was paid in full on December 14, 2023 determined the matter was complete. On or about May 1, I received a recall notice from MBUSA. The ID is 2024040002 and the NHTSA Recall ID is 24V207. This recall specifically called out the 48V battery connections and potential for misconnections to cause fire. This is the exact issue that is clearly articulated in the service report (attached). After six weeks attempting full reimbursement, MB considered the issue closed and their official position was that I was only entitled to $337.08 for the actual recall of the battery connection check. Of course the connections would now be correct as they fixed them and replaced the cables that caught fire. I am escalating this to your department and seek full reimbursement from Mercedes for this repair performed. This failure occurred prior to the recall notice and is the singular event that the recall is to mitigate that happened.

Jul 09, 2024

The dashboard screen stops working randomly. This is not related to extreme outdoor temp conditions. Mercedes dealer could not reproduce the problem and therefore could not offer any solution. Problem has happened 5-6 times over the past 7 months. Please watch video below: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

May 01, 2024

Vehicle would not start. 48v battery light came on. Waited 15 minutes, vehicle started, drove to dealership who did diagnosis. Battery replacement required $1800 + $1200 labor. 2020 vehicle with 61K miles. Bought certified vehicle from MBZ dealership, added a MBZ 3 year or 100K mile extended warranty but this battery is considered a wear and tear item not covered. That would be fine except for the fact that this battery issue is well known to MBZ as it has multiple reported instances of failure on vehicles with 6K to 60K miles.

Dec 26, 2023

I have noticed a significant issue with the AC vent system of my Mercedes GLS 450. The vents seem to be distributing mold smell already took my vehicle multiple times to park place Mercedes in Dallas and they performed service but the issue is persistent. I have taken the vehicle to my local Mercedes service center, where they attempted to address the issue. However, despite their efforts, the problem has persisted. This defect is impacting not only the comfort of my driving experience but also the overall value and performance of the vehicle. We had GLE in my family that had the same issue we took it to Park Place and complained about this many times and end up selling the vehicle as they never resolved the issue. Vehicle: 2017 MERCEDES-BENZ GLE350 VIN: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Aug 21, 2023

+ 3 more complaints for this component

ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM

3 complaints

While driving, vehicle has abruptly stopped/engine turned off causing car to not accelerate and come to a stop. One instance was on a busy freeway, causing our family to pull off the interstate with nearly no curb, risking rear-end collision due to the abrupt stalling of the vehicle. In this instance, the 48 volt battery failure warning, engine overheat warning, engine light warning came on. When MCB dealership evaluated the vehicle, there were no stored associated error codes and MCB service returned the vehicle to me saying that the issue did not occur when they drove it. The same issue occurred again 5 months later, this time in a busy intersection, where the car would not accelerate and I was forced to pull of the road. The check engine light as well as other failure lights came on. THe car was returned to MCB service and again, no error codes were stored and the dealership said they could not find the cause of the problem. This vehicle issue (reported to the NHTSA by several other 2020 GLS owners) is a LIFE-THREATENING DANGEROUS VEHICLE PROBLEM . Both times, the engine abruptly failed and the car would not accelerate in the middle of heavily trafficked roads/freeways, which could easily result in a catastrophic accident. Both times, the vehicle did not store the associated error codes, despite the display illuminating several warning lights, including the check engine light. THe unreliability of this expensive vehicle is particularly concerning to me as it is used to transport young children. Mercedes is taking no accountability for this vehicle failure and claims they have not heard of this issue prior, which is clearly inaccurate given that it has been reported to NHTSA by several other GLS owners. This is an enormous safety liability, not only for the owners of this vehicle, but for innocent bystander drivers who could easily have a rear end collision with the car as it fails to accelerate and the engine abruptly stalls/stops.

May 17, 2022

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. In looking at the issue on line this appears to be a known problem to Mercedes. They are even facing a class action lawsuit for it in the same model year GLE, which is based on many of the same systems. SOmeone is going to get killed when their vehicle stalls in the middl eof the highway.

Nov 02, 2021

WE PURCHASED A NEW 2020 MERCEDES BENZ GLS 450 IN OCTOBER 2019 FROM THE OAKLAND DEALERSHIP AND SHIPPED THE CAR TO HAWAII. THE VEHICLE IS NOW 117 MONTHS OLD AND HAS ABOUT 4100 MILES. BECAUSE OUR VEHICLE IS LIGHTLY USED WE ARRANGED FOR MERCEDES BENZ TO SUPPLY AND INSTALLED A 'BATTERY MINDER' TO KEEP THE VEHICLES 48 VOLT SYSTEM CHARGED WHEN WE ARE AWAY FOR AN EXTENDED TIME. HOWEVER WE DID NOT HAVE THE BATTERY MINDER HOOKED UP AT THIS TIME BECAUSE WE ARE USING THE VEHICLE ON A WEEKLY BASIS. ON MARCH 7, 2021 WE EXPERIENCED A "48 VOLT BATTERY MALFUNCTION' WHICH LEFT OUR CAR DISABLED ON THE SIDE OF AN UPHILL MAJOR ROADWAY. THERE WAS NO WARNING JUST A SUDDEN EXTREME LOSS OF POWER, SUPPLEMENTAL SYSTEMS SUCH AS THE AC DEACTIVATED, WARNING LIGHTS FLASHED AND OUR VEHICLE COASTED TO THE SIDE OF THE ROAD. I BELIEVE THE BRAKE SYSTEM WAS ALSO DIMINISHED BY THE LOSS OF ELECTRICAL BOOST. AFTER A WHILE WE WERE ABLE TO RESTART THE VEHICLE AND BEGAN TO 'LIMP HOME'. THE VEHICLE WAS NOT ABLE TO ACCELERATE AND WE EXPERIENCED 'OVER HEATING' WARNINGS ( IN RED ) AND HAD TO STOP THE VEHICLE TO COOL THE ENGINE. WE ARRANGED FOR MERCEDES BENZ ROADSIDE ASSISTANCE TO TOW THE VEHICLE TO THE KONA MERCEDES BENZ SERVICE CENTRE THE NEXT DAY. YELLOW ENGINE WARNING LIGHTS REMAINED ON WHEN THE VEHICLE WAS PLACED ON THE TOW VEHICLE.WE HAVE USED THE KONA SERVICE CENTRE SINCE IT WAS OPENED, THE TEAM LED BY PAULETTE GANTALA IS VERY CAPABLE AND THEY PERFORM EXCELLENT WORK. AFTER SEVERAL DAYS WE LEARNED THAT THE CAUSE OF THE MALFUNCTION WAS NOT FOUND AND WE WERE TOLD TO 'MONITOR THE SITUATION'. I ATTACHED THE SERVICE REPORT WHICH DESCRIBES THE EXTENSIVE INVESTIGATIVE WORK COMPLETED BY THE KONA MERCEDES SERVICE CENTRE. WE ARE VERY CONCERNED THIS MALFUNCTION IS A SAFETY RELATED ISSUE AND NEEDS TO BE ESCALATED. SUDDEN UNEXPECTED LOSS OF POWER CREATES EXTREMELY DANGEROUS SITUATIONS.

Mar 14, 2021

FUEL/PROPULSION SYSTEM

2 complaints

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 confirmed/replicate it. No the vehicle or component has not been inspected by the police, insurance representatives or others? But has been taken to the dealership, not the manufacturer. No warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear?Just when it leaks there is a strong gas smell as well as a visual of where the leak is coming from.

Dec 15, 2025

TL* THE CONTACT OWNS A 2020 MERCEDES-BENZ GLS450. THE CONTACT STATED SHE NOTICED A FUEL ODOR COMING FROM THE VEHICLE WHEN THE WINDOWS WERE OPEN. THE CONTACT SOUGHT MEDICAL ATTENTION DUE TO BREATHING PROBLEMS. THE VEHICLE WAS TAKEN TO LOCAL DEALER ED HICKS IMPORTS LOCATED AT 3102 S PADRE ISLAND DR, CORPUS CHRISTI, TX 78415 (361) 854-1955, WHERE IT WAS DIAGNOSED THE FIRST TIME WITH A MELTING STICKER ON THE CADILLAC AND IT NEEDING TO BE REMOVED. THE VEHICLE WAS REPAIRED BUT CONTINUE TO EXPERIENCE THE FAILURE. THE CONTACT STATED ON 12/21/2019, WHILE DRIVING 7 MPH, WHEN SHE HEARD MULTIPLE LOUD ABNORMAL NOISES (EXPLOSIONS). THE VEHICLE WAS TAKEN BACK TO THE SAME DEALER, WHERE IT WAS DIAGNOSED THAT THE CADILLAC CONVERTER AND TURBO NEEDED TO BE REPLACED. THE VEHICLE HAD NOT BEEN REPAIRED AS OF YET. THE MANUFACTURER HAD NOT BEEN INFORMED OF FAILURE. THE FAILURE MILEAGE WAS 1,000.

Jan 15, 2020

Injuries: 1

SUSPENSION

2 complaints

The suspension has failed despite changing engine mounts. It is available for inspection if needed. I also believe there is Premature wear of the front struts and rear shock absorbers. This can affect vehicle handling and control, increasing the risk of a crash. There were no warning lamps and it has been inspected by various mechanics including Mercedes

Apr 01, 2025

The shock absorbers have prematurely failed as other recalled 2020 GLS vehicles, but our VIN is not showing under the recall campaign 20V329000. Can our vehicle be included on this recall?

Jan 21, 2025

FORWARD COLLISION AVOIDANCE

2 complaints

We intermittently experience phantom braking, including on the highway with no objects or vehicles ahead of us (for example, not on a curve, no vehicle visible within half a kilometer). Vehicle abruptly slows. This includes when in a lane (no lane change). It also can occur during a properly indicated lane change. It occurs when we are driving the posted limit. It also occurs when there are no parallel nearby roads. This appears to be a significant safety issue.

Aug 18, 2024

I have received multiple notifications over several months that read "Camera view restricted". This impacts the collision avoidance and adaptive highbeam assist functions. Dealer has offered no service recommendations.

Jul 10, 2024

UNKNOWN OR OTHER

1 complaint

The sunroof spontaneously shattered while driving down the interstate. No other cars involved and no rocks or debris caused it. It was inspected and repaired at a Mercedes dealer, however, Mercedes refused to cover the repair under the pre-owned certified warranty. We had to file an insurance claim. In doing research, it appears this is a common and ongoing problem with various models of Mercedes.

May 02, 2025

POWER TRAIN

1 complaint

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

Apr 10, 2025

ELECTRICAL SYSTEM,ENGINE

1 complaint

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 Carrera Motors, I contacted Mercedes customer care on March 10 and was issued a case number (#[XXX]) for the harness issue. She mentioned that someone would get back to me within 3 business days. Unfortunately, 3 days went by without a response. I called and left 3 messages over the next 2 days. Finally, MBUSA returned my call and instructed me to take the car to an authorized Mercedes dealer. At my own expense, I had the car towed from Carrera Motors to Autobahn Motors in Belmont CA on March 18. Mark Nissen at Autobahn was responsible for the service of my vehicle. He and his services team have verified that the electrical harness was seriously damaged and needs to be replaced at a cost of $5,009.99. Replacement is considered critical, and it’s been identified as a serious safety issue. This issue has not been resolved. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Apr 01, 2025

ENGINE

1 complaint

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 off message - at this point vehicle deaccelerated over riding my control of vehicle speed. Had to navigate from far left lane to right hand emergency lane at 40 mph - very dangerous maneuver as losing power. Vehicle was towed and received a 48v software update - software that deaccelerates the vehicle with no override for safety is a real problem INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Jan 31, 2025

VISIBILITY/WIPER

1 complaint

intermittent rear view camera inoperable when you shift from park to reverse. Doesnt come on even if you turn off and tune on the engine.

Sep 19, 2024

VEHICLE SPEED CONTROL,FORWARD COLLISION AVOIDANCE

1 complaint

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 dealership has inspected this vehicle INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Sep 11, 2024

SERVICE BRAKES

1 complaint

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 May.

Jun 01, 2024

SERVICE BRAKES,BACK OVER PREVENTION,FORWARD COLLISION AVOIDANCE

1 complaint

Today around 6:47pm. I was reversing my car and I noticed another car in my backup camera and tried shift the gear shift to drive but it didn't work and stayed stuck on reverse and would not moved and the brake pedal and emergency brake wouldn't work.

May 07, 2024

Crash: 1

AIR BAGS,UNKNOWN OR OTHER,FORWARD COLLISION AVOIDANCE

1 complaint

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 driver backed out of a company driveway into the road with no people helping. With traffic totaled right front tearing wheel off. No air bags deployed, I do not believe accident avoidance nor auto braking employed, MB safety and accident location didn’t activate and not sure passenger seat belt pre tightened. Police report Saco Maine 23-113-AC . MBUSA notified. Car held for them to examine. 4 weeks later have heard nothing other than “ we’re working on it”police and Insurance found 0 fault for me. Car totaled for repair cost

May 31, 2023

Crash: 1

Injuries: 2

POWER TRAIN,ELECTRICAL SYSTEM,ENGINE

1 complaint

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 down engine immediately”. The first error was a 48V battery system charging failure, and the second was a warning that coolant was too hot. The instrument panel and steering and brakes did not lose power, but the accelerator no longer worked, and the vehicle slowed down to about 35mph. I had to merge across 4-5 lanes of rush hour traffic at this speed (sketchy) to make it to the side of the freeway, and was able to exit safely and stop in a safe spot. Upon turning off the vehicle for a few minutes and then restarting it, a generic check engine light remained on afterwards. I had the vehicle towed to a Mercedes dealer where the fault(s) are currently being diagnosed. According to the dealer, they are in touch with MBUSA Engineering due to the nature of the fault codes. The vehicle had recently undergone a 50,000 mile routine service without any problems being flagged. The safety implications of this incident are clear: with no ability to match the speed of the flow of traffic, I could have been rear-ended or involved in a collision as I limped across the freeway to safety. I am fortunate that the vehicle had enough residual kinetic energy that I didn’t end up stuck blocking a freeway lane in rush hour traffic. Searching online for similar issues, this appears to be a known manufacturing issue with the mild hybrid inline-6 engine in this model of vehicle. For instance, all of the top Google hits for the term “GLS 48V battery failure” yield relevant and similar reports from other drivers, including summaries from consumer lawyers like this one: https://lemberglaw.com/mercedes-benz-gle-battery-electric-problems/

Sep 23, 2022

POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM

1 complaint

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, Michael (initial intake) told me "I have seen this issue before."

May 19, 2022

ELECTRICAL SYSTEM,UNKNOWN OR OTHER

1 complaint

Upon starting the car, the screen of the 2020 Mercedes Benz GLS 450 remained blank. This includes the portion of the dashboard that reads speedometer, gas, temperature, RPM. The engine was running and truck could still be driven. The vehicle is available for inspection upon request. This is a major safety issue as the driver does not have visibility to the dashboard with all it's important information. The vehicle is currently at Mercedes Benz dealership undergoing diagnostics. The vehicle is being inspected by Mercedes Benz (manufacturer). See prior comment. There were no warning lamps or messages that appeared prior to the problem. Shortly after driving home (with the blank screen) the car was shut off and restarted and the display came back on but then the check engine light was displayed.

Oct 05, 2021

STEERING,POWER TRAIN,FUEL/PROPULSION SYSTEM

1 complaint

We were driving the vehicle at about 30 MPH on a road when suddenly the engine completely shut off. There was no more power steering and no warning that it turned off. We got the car slowed down and once we came to a stop the car put itself in Park. After that we could restart it and keep driving with the car acting very different. This then happened again later on in the day going about 20 MPH up to a stop light. It shut itself off and luckily we were able to come to a stop with the brakes without running into the intersection and no one hitting us from behind. Once again it put itself in Park. We were able to restart the car and drive again with diminished power and really weird shifting from the transmission. The check engine light turned on both times and when we got it to the dealership the next morning all the check engine lights were off again. This is extremely dangerous to the driver and occupants. Our little son was in the back seat. We commute with this car in southern california and if this were to happen on the freeway it would be disastrous. Everyone is at risk with this car. It will just stop without any warning signs and you can have someone rear end you. And the power steering turns off also which if the car turns off in a corner on the freeway you will have no way of controlling the vehicle and will just go into the middle barrier or oncoming traffic. This could be even worse if driven on a mountain road and you loose all power of the vehicle. We will not be driving the car anymore since we have no idea when it will shut off again while driving.

Aug 05, 2021

SEATS

1 complaint

CLIP MISSING FROM RIGHT HAND SIDE PASSENGER SEAT (2ND ROW), CAUSING THE SEAT TO FOLD ALL THE WAY FORWARD MULTIPLE TIMES ON ITS OWN. THIS HAPPENED WHEN THE CAR WAS STATIONARY. THE DEALERSHIP FIXED THE ISSUE AND ADDED THE MISSING CLIP.

Nov 23, 2020

4.9/5.0

28 reviews

Frequently Asked Questions

How many problems does the 2020 MERCEDES-BENZ GLS-Class have?

The 2020 MERCEDES-BENZ GLS-Class currently has 31 owner-reported complaints according to NHTSA database. These complaints are organized by component to help identify common issues.

What are the most common problems with 2020 MERCEDES-BENZ GLS-Class?

The most common problems reported for the 2020 MERCEDES-BENZ GLS-Class are organized by component above. Each component section shows owner-reported issues, crash reports, and fire incidents to help identify patterns and problem areas.

Where does this 2020 MERCEDES-BENZ GLS-Class problem data come from?

All problem and complaint data for the 2020 MERCEDES-BENZ GLS-Class comes directly from the National Highway Traffic Safety Administration (NHTSA) database. These are real complaints submitted by actual vehicle owners.