Home · 2021 Mercedes-benz GLS · Complaints

What 36 owners told NHTSA about the 2021 Mercedes-benz GLS

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (36)Crash / fire / injury (5)Electrical system (16)Engine (4)Driver assistance (3)Lane Departure (3)Fuel system (2)Seats (2)Visibility & wipers (2)Airbags (1)Body & structure (1)Seat belts (1)

5 of 36 complaints match · crash/fire/injury only · clear filters

May 16, 2025Electrical systemSeatsFire

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 INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6

NHTSA ODI 11661377

Sep 25, 20241 injury

I was driving only 30mph through my suburban neighborhood bringing my kids to school in the morning when a loud shotgun sound hit my car causing me to be distracted and distraught. My entire sunroof had exploded on me for no reason. Mercedes is currently undergoing a class action lawsuit for this. But since it is not completely yet, I’m being told I need to pay $3700 out of pocket for the default damages and servals days without a vehicle.

NHTSA ODI 11616529

Aug 25, 2024Electrical systemSeatsFire

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

NHTSA ODI 11610699

Apr 20, 2024Crash

I was driving and all of a sudden. The car felt like it was swirling left and right and I was trying my best to straighten the steering wheel, but it felt like I had no control of the car. I eventually hit the median on the road and while all this was happen my dashboard was flashing with all the lights, but my eyes were on the road trying to fix the steering wheel so I don’t know exactly what light was on. When I hit the median, I was finally able to regain full control of the car. It kind of felt like my car was accelerating and swerving at the same time and I was not even stepping on the pedal. I am not sure what caused this, but my car was recently in the shop for some battery issue.

NHTSA ODI 11584224

Dec 17, 2021AirbagsCrash1 injury

The contact owns a 2021 Mercedes Benz GL550. The contact stated that while driving 30 -35 mph an unknown vehicle crossed her path, the driver depressed the brake pedal but was unable to stop before colliding with a vehicle. The steering wheel air bag split open and deployed. The contact sustained injuries, the inside of her right arm was cut. The air bags on the floor deployed and contact sustained severe burns on her shin medical attention was provided. The contact stated she still has an open wound. The distance warning indicator light was illuminated. There was no reported fire. The police were on the scene however, there was no police report filed. The vehicle was towed to an independent lot. The local dealer was contacted but the vehicle was not diagnosed. The manufacturer was contacted but, no further assistance was provided The failure mileage was approximately 3,000. The contact mentioned the floor air bag was removed by the tow company. The VIN was not available. UPDATES- Due to the impact of the airbags on the floor, it caused major bruising, restricted blood flow and two hematomas to my right shin. In August of 2020 I had major surgery to remove the hematoma and healing for this open wound took seven months. I have a major scar on my right shin. Additionally, I have a scar on the inside of my lower right arm as the airbag on the steering wheel split open and cut my arm. Steigler Automotive Repair, in Reseda, California repaired all damages to my vehicle (approximately $30,000k) and the car was released back to me.

NHTSA ODI 11444154

Working with the data? Download all 36 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2021 Mercedes-benz GLS verdict →