Home · 2021 Mercedes-benz GLS · Complaints
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.
4 of 36 complaints match · Engine · clear filters
Delivered an unfinished or car with a broken part,Seat Problem not locking properly, Electrical Problem, Engine Light Came on, ESP warning, Suspension Problem, Battery Problem, Steering Jerking, Mirror Problem which they said Mercedes Benz aware of it, some sort of sound, car getting hot excessively.
NHTSA ODI 11574364
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.
NHTSA ODI 11500946
Repeated failures of 48 volt battery system has shut vehicle totally off while under highspeed and in traffic
NHTSA ODI 11500122
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!
NHTSA ODI 11465737
Working with the data? Download all 36 complaints as CSV · fetched from NHTSA July 20, 2026