2021 Mercedes-Benz GLS450 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2021 Mercedes-Benz GLS450, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Electrical1446.7%
- Driver assistance413.3%
- Engine310.0%
- Interior & seats26.7%
- Seat belts13.3%
- Tires & wheels13.3%
- Body & structure13.3%
- Visibility13.3%
- Fuel system13.3%
- Other / unspecified13.3%
- Powertrain (other)13.3%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
On [XXX], I was heading home from work traveling [XXX] on [XXX] through Atlanta's usual heavy traffic. I smelled smoke inside my car and saw fire flames coming from under my passenger seat. My initial reaction was to try to put the fire out with my hat without burning myself. Also, I had to try to navigate across multiple lanes of traffic without hitting anyone and avoiding anyone hitting me. Safely, i reached the side of the interstate and exited the vehicle. As I stood from afar watching my vehicle burn; the reality sat it that a few minutes earlier that could have been me trapped burning inside, injured or even death because something had failed in my vehicle. Later, when I finally arrived home, I started researching on the internet to see if anyone else had experienced problems with their MB 450 GLS catching fire. Surprisingly, I found that recalls had been issued in April 2022 and March 2024 for a possible fire risk from a 48volt loose ground wire issue under the passenger seat. At that time supposedly there were no reported injuries or crashes related to this issue until now. If I am the first to witness this issue, then so be it because I saw the fire burning from inside under my passenger seat before it FULLY torched my vehicle I reported this issue first to Progressive Insurance and Mercedes-Benz Corporate. Progressive has provided my transportation according to policy for my first 30 days. As I approached the end of my rental period, I spoke with MB Corporate to see if there was anything that they could do as far as providing me transportation. I was told that there was nothing that they could do because they were not a dealership with cars to loan. The joint vehicle fire investigation was schelduled for 29 April 2025. On 25 April 2025, Progressive informed me that MB Corporate had moved the fire investigation date to 29 May 2025. NOW, what am I suppose to do? It has been almost two months that I have been without a vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMAT
System malfunctioned detail: 48v battery malfunction, 12v battery malfunction. Safety concern: I was driving on [XXX] , the battery malfunction warning suddenly pop up, and I couldn't accelerate my car beyond 30 MPH, my whole family were on the car during that time. it's life threatening issue needs to be addressed. Luckily we managed to pull over to a safe border way. It's first time I encountered this issue, but on [XXX] , seems like many people encountered it. Dealer is inspecting the issue currently. orange warning msg pop up first says "48v battery malfunction", few minutes later become red warning msg, while I pulled my car to the sideway, it became red "12v battery malfunction". INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
Mercedes has launch a Campaign Nr 2022010001 Campaign Desc: 21P0699002 in which will retrofit augmented reality camera in 1147 vehicle model year 2021-2022 . My car came without this camera due to the chip shortage during the COVID . I contacted Mercedes Benc USA and the rep told me to contact NHTSA in order to add my car as a part of this Campaign in order to repair this safety future on my car. This camera affect Lane keeping assistance and Lane Departure warning.
On four occasions my car has stalled while in traffic very early in my ownership and then it happened again today with my family in the car and nearly caused an accident. The entire dash lights up with every warning when it happens. Sometimes the check engine light comes on after I shut the car off and restart it. My Mercedes dealer has had it in multiple times for this reason. The last time it was in for this (May of 2022) they "reprogrammed" the entire car. It happening again today has really made me lose a lot of faith in the vehicle, especially since we purchased it for the safety factors. I read online that there are many others who have experienced this. Some say it is related to the 48V battery. I don't care what Make or Model or how expensive it is, a new car should NOT stall in traffic and should be looked into. Thank You.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
On four occasions my car has stalled while in traffic very early in my ownership and then it happened again today with my family in the car and nearly caused an accident. The entire dash lights up with every warning when it happens. Sometimes the check engine light comes on after I shut the car off and restart it. My Mercedes dealer has had it in multiple times for this reason. The last time it was in for this (May of 2022) they "reprogrammed" the entire car. It happening again today has really made me lose a lot of faith in the vehicle, especially since we purchased it for the safety factors. I read online that there are many others who have experienced this. Some say it is related to the 48V battery. I don't care what Make or Model or how expensive it is, a new car should NOT stall in traffic and should be looked into. Thank You.
Repeated failures of 48 volt battery system has shut vehicle totally off while under highspeed and in traffic
Too few reports in this category for a page of its own — they appear in the full complaint list.
Interior & seats
Reports naming seats, latches, locks, linkages and interior fittings.
From owner reports, verbatim
On [XXX], I was heading home from work traveling [XXX] on [XXX] through Atlanta's usual heavy traffic. I smelled smoke inside my car and saw fire flames coming from under my passenger seat. My initial reaction was to try to put the fire out with my hat without burning myself. Also, I had to try to navigate across multiple lanes of traffic without hitting anyone and avoiding anyone hitting me. Safely, i reached the side of the interstate and exited the vehicle. As I stood from afar watching my vehicle burn; the reality sat it that a few minutes earlier that could have been me trapped burning inside, injured or even death because something had failed in my vehicle. Later, when I finally arrived home, I started researching on the internet to see if anyone else had experienced problems with their MB 450 GLS catching fire. Surprisingly, I found that recalls had been issued in April 2022 and March 2024 for a possible fire risk from a 48volt loose ground wire issue under the passenger seat. At that time supposedly there were no reported injuries or crashes related to this issue until now. If I am the first to witness this issue, then so be it because I saw the fire burning from inside under my passenger seat before it FULLY torched my vehicle I reported this issue first to Progressive Insurance and Mercedes-Benz Corporate. Progressive has provided my transportation according to policy for my first 30 days. As I approached the end of my rental period, I spoke with MB Corporate to see if there was anything that they could do as far as providing me transportation. I was told that there was nothing that they could do because they were not a dealership with cars to loan. The joint vehicle fire investigation was schelduled for 29 April 2025. On 25 April 2025, Progressive informed me that MB Corporate had moved the fire investigation date to 29 May 2025. NOW, what am I suppose to do? It has been almost two months that I have been without a vehicle. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMAT
1. Unknown, smoke started coming from under the passenger side seat, car is a complete loss. 2. Smoke damaged my lungs, there was a large amount of exploding glass, and it could have led to a structure fire. 3. Not applicable 4. In process, but it was recalled for this issue 5. No
Too few reports in this category for a page of its own — they appear in the full complaint list.
Seat belts
Reports naming seat belts, buckles, retractors and pretensioners.
From owner reports, verbatim
The contact owns a 2021 Mercedes-Benz GLS450. The contact stated while driving 40 MPH, the vehicle in front made a sudden stop, causing the contact to make a sudden stop, causing the contact’s children to fall out the seats. The contact notice that the third-row buckle latch had malfunctioned. The vehicle was taken to the dealer and the third-row driver’s side latch was replaced. On another occasion while driving 40 MPH, the contact heard squeaking noise coming from the rear of the vehicle. The vehicle was taken to the dealer for diagnostic test, and the mechanic stated that no failure was found. The manufacturer was contacted, and a case was filed. The failure mileage was 25,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Tires & wheels
Reports naming tires, wheels, hubs, or the tire-pressure monitoring system.
From owner reports, verbatim
Tire Size 270/50 R 20 Tire type: Cooper Discover SRX These tires came with my 2021 Brand new Mercedes GLS 450. I bought this car in May 2021. I have had this car for only 1 1/2 years with 22K miles; tires thread are down to 0. I have kids, and this is my primary family car. I had a few bad to worst experiences during wet weather conditions. I took my car for my 20K service milestone; My Mercedes dealer acknowledged worn-out tire condition; advised me to purchase new tires. They never informed me about warranty replacement. I just got my tires replaced with non- cooper brand. My tire dealer shared the condition of my old tires; it was unbelievingly in horrible/Hazardous condition. See attached images of the tire. These tires should be recalled, as they are unsafe and risky to drive. Thanks, Tarun
Too few reports in this category for a page of its own — they appear in the full complaint list.
Body & structure
Reports naming the vehicle structure, frame, body panels, doors, hood and trim.
From owner reports, verbatim
My Mercedes has the automatic doors that close. I was closing the driver door with my back to the door and felt my thumb get caught in the drivers door. I attempted to remove it but, could not remove it. I had to watch the door slowly close and seal/crush with my finger smashed within the door. My wife helped me open the door and the top of my finger was smashed, as my wife said, like [XXX]. I went to the emergency room in St Petersburg Florida and as diagnosed with an acute non-displaced fracture through the distal phalanx of the first digit. The door just slowly closed on the finger. if it was a child's hand. wow INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
Too few reports in this category for a page of its own — they appear in the full complaint list.
Visibility
Reports naming windshields, glass, wipers, defrosters and mirrors.
From owner reports, verbatim
Wipers - I have had repeated issues with the windshield wipers on this vehicle. I have taken it to the dealership 3 times and I have not gotten a satisfactory solution to the issue. The wipers skip across the windshield making intermittent wipers distracting. The dealer's service manager said this is a known issue caused by the OEM wiper blades. I've also been told they can't recommend a solution. AC - The AC in my 2021 GLS 450 smells like moldy socks which makes me suspect there is some build up on the coils or in the vent. I had the vehicle serviced 2 times at the dealership for this issue where the tech informed me the issue was not likely to be resolved by the $500 service I had paid for. The service was discounted down to $307.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Fuel system
Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.
From owner reports, verbatim
The contact owns a 2021 Mercedes-Benz GLS450. The contact received notification of 23V445000 (Fuel System, Gasoline) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time to for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool showed no open recall.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Other / unspecified
Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.
From owner reports, verbatim
Both rear wheels on this vehicle have developed cracks which leads to tire pressure loss. Apparently, this is a common issue with Mercedes' heavier vehicles like the GLS and S series sedans. To be clear, I did not hit anything. I did not do any unusual driving. Both rear tires are fine. While you expect that certain components on a vehicle will have problems, it is also reasonable to expect that wheels will not crack prematuraly. Mercedes is aware of the problems. They were named in a class action lawsuit that was dismissed because cars were out of warranty. Warranty or no warranty, this is a major safety issue as a loss in tire pressure can be catastrophic.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
2021 GLS 450 VIN # 4JGFF5KE9MA404568 Purch: Nov 26, 2022 UAG Fairfield Auto Group CM, LLC,DBA MERCEDES BENZ OF FAIRFIELD Odometer Date of Purchase 10,084 Odometer Currently *13,700 (onboard notification) TIMELINE: Total vehicle system fails while driving on highway lost engine, steering, power suddenly - stranded. November 27, 2021 Loud interference noise coming from MBUX screen, faulty graphics flashing, app not functioning. Extreme Loud “blower” noise coming from heater. Vehicle start would not work as the vehicle did not recognize key was in vehicle even though it was in the vehicle. Informed MB Fairfield. Vinnie said that the noises were “normal” . We knew this was incorrect. December 15, 2021 Informed MB Fairfield of recurring problems December 18, 2021 Car would not start/did not recognize key in a parking lot. Went into a local business for help, the owner of the shop coincidentally recently bought the same model and reported similar issues. Shop owner informed us that the “blower” noise coming from our HVC was definitely NOT normal. Informed MB Fairfield of recurring problems above. December 20, 2021 Car would not start/did not recognize key - blower issue. Informed MB Fairfield of recurring problems and received no help other than the dealership said not an issue and was “normal” "the app has glitches that they can’t “fix”. December 23, 2022 Car would not start - notified MB Fairfield of recurring problems above. He reluctant to admit problem with vehicle, rather blamed it on the app or software. Regardless of root cause=vehicle was faulty and was not functioning safely and at times completely inoperable. January 4, 2022 Catastrophic failure, 5PM in dark while in fast lane on I95, vehicle MBUX interface made loud noise, flashing illegible graphic. Car in shop March 11, 22 through April 29, 22. May 1 failed at 60MPH on highway- stranded. 2 two trucks confirmed UNSAFE TO DRIVE REFUSED TOW. HAS BEEN AT DEALER 90 DAYS PLUS!
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .