15 of the
88 complaints about the 2020 Mercedes Benz GLC 300 are about the
driver-assist systems — 17% of everything
reported for this model year.
Half of the failures with a mileage on record happened before
35,886 miles.
On August 15, 2025, I was driving my Mercedes-Benz GLC 300 4MATIC on the freeway under normal conditions. Without any warning lights, error messages, or prior signs of mechanical issues, the vehicle suddenly and completely lost power. The accelerator pedal became unresponsive and felt locked, and the vehicle came to an abrupt stop in the middle of an active freeway, in the second lane from the left. I had no ability to control or prevent the stoppage. This unexpected power loss directly led to a rear-end collision. The vehicle behind me sustained severe front-end damage, including airbag deployment. My passenger and I were in shock and suffered whiplash and physical injuries, with pain and bruising following the impact. I suspect the most likely causes may be an Electronic Throttle Control failure or a false activation of an Active Safety System. I opened a case with MBUSA (Case #16298894) immediately after the incident, but I have not received any updates on the investigation. This was a dangerous and life-threatening failure, and I am deeply concerned that it could occur again to other drivers if not addressed.
NHTSA complaint #11689240 — an unverified report by a vehicle owner.
San Francisco, CACrash3 injured
FORWARD COLLISION AVOIDANCE: WARNINGS
On August 15, 2025, I was driving my Mercedes-Benz GLC 300 4MATIC on the freeway under normal conditions. Without any warning lights, error messages, or prior signs of mechanical issues, the vehicle suddenly and completely lost power. The accelerator pedal became unresponsive and felt locked, and the vehicle came to an abrupt stop in the middle of an active freeway, in the second lane from the left. I had no ability to control or prevent the stoppage. This unexpected power loss directly led to a rear-end collision. The vehicle behind me sustained severe front-end damage, including airbag deployment. My passenger and I were in shock and suffered whiplash and physical injuries, with pain and bruising following the impact. I suspect the most likely causes may be an Electronic Throttle Control failure or a false activation of an Active Safety System. I opened a case with MBUSA (Case #16298894) immediately after the incident, but I have not received any updates on the investigation. This was a dangerous and life-threatening failure, and I am deeply concerned that it could occur again to other drivers if not addressed.
NHTSA complaint #11689240 — an unverified report by a vehicle owner.
Grovetown, GA
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
For the past 6 months, the monitor in my SUV wont come on when I turn on the truck. Even when I turn the vehicle off, remove the key and step out of the vehicle, it will still do it until like the I next day. Often, still, when I am putting my car in reverse, the camera does not work. Very often. This put the safety of me and my children at risk as this is not what I am accustomed to as far as safety is concerned. I took the car to Mercedes Benz dealership here in Augusta GA and showed multiple videos of the screen not coming on or not working when I had it in reverse, they were to charge me $6000 to get this fixed at no fault of my own. There were not prior warnings. But what was odd was when I typed in my VIN number into the Mercedes Benz website, the recalled appear. When I called Mercedes Benz, it was stated that my vehicle was not apart of the recall with the same exact problem.
NHTSA complaint #11674358 — an unverified report by a vehicle owner.
at 35,886 milesKouts, IN
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated while attempting to reverse, the back over prevention camera displayed a blank screen. The vehicle was not taken to an independent mechanic or dealer to be diagnosed. The contact stated that the failure had occurred on several occasions. The vehicle was repaired. The manufacturer was notified of the failure, and informed the contact that the VIN was not under recall for the failure. The contact related the failure to NHTSA Campaign Number: 22V232000 (BACK OVER PREVENTION); however, the VIN was not included in the recall. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was 35,886.
NHTSA complaint #11656070 — an unverified report by a vehicle owner.
Cortlandt Manor, NY
FORWARD COLLISION AVOIDANCE: WARNINGS
SRS malfunction warning displayed on vehicles dashboard. Vehicle was diagnosed and displayed code B009749 Indicating: the crash sensor on the right hand side has a malfunction. There is an internal electrical fault.
NHTSA complaint #11618239 — an unverified report by a vehicle owner.
Las Cruces, NM
BACK OVER PREVENTION: SENSING SYSTEM: CAMERA
Center COMAND screen malfunctions. No rear camera view when reversing when screen does not work. Dealer attempted a repair but issue remains. Parts ordered for replacement.
NHTSA complaint #11581247 — an unverified report by a vehicle owner.
Menlo Park, CA
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
My car has Distronic (radar cruise control), and it worked perfectly until I got my car back after routine maintenance (oil change) at my Mercedes Benz dealership in late summer of this year (2023). Now, the system is behaving dangerously aggressive, for example breaking too late for cars in front which have slowed or stopped in stop-and-go freeway traffic. It is acting like the dealership installed a software update for the wrong car (perhaps a lighter weight or lower powered car.) The system has become so disconcerting I've mostly stopped using it because it feels so unsafe.
NHTSA complaint #11552405 — an unverified report by a vehicle owner.
at 60,000 milesWestminster, CO
BACK OVER PREVENTION
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that the rearview camera displayed a reverse mirror image. The contact related the failure to NHTSA Campaign Number: 22V232000 (Back Over Prevention). The vehicle was not diagnosed nor repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 60,000.
NHTSA complaint #11512856 — an unverified report by a vehicle owner.
Lafayette, IN
BACK OVER PREVENTION
The contact owns a 2020 Mercedes-Benz GLC300. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
NHTSA complaint #11491174 — an unverified report by a vehicle owner.
Ormond Beach, FL
BACK OVER PREVENTION: REARVIEW SYSTEM BRAKING
In July 2021, Mercedes notified me of NHTSA Recall #21V354 n certain MY 2019-2021 Mercedes-Benz vehicles listed above, under certain conditions, the MBUX multimedia system might not start and the display might remain black, or could reboot unintentionally after 50 seconds of initial startup. Accordingly, the rearview camera image might not be displayed or the display might be interrupted which could reduce the driver’s rear view, and increase the risk of a crash or injury. Mercedes indicated the update would be pushed to the car Over the Air (OTA). More than a year later, the update still has not been pushed OTA. I took the car to the Mercedes dealer that I bought the car from and they were unable to install the update either. It's apparent that Mercedes OTA process does not work for all vehicles, and Mercedes has provided me no method by which I can get the update completed.
NHTSA complaint #11475234 — an unverified report by a vehicle owner.
Self driving assist, adaptive cruise , emergency braking assist do not work. Taken to dealer three times , unable to correct. Returned to customer with out paperwork documenting repair of safety systems. Problems are still in I repaired state. Emergency braking system warning message has activated 15-20 times after receiving car back. Other existing problems are still on going as well. Requested District service Manager consult the situation and advise. Love car , want to have repaired . Looking to add additional GLC to household . Hope repair is possible . ????! Hate to have accident, bad for health. Please contact. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
NHTSA complaint #11465447 — an unverified report by a vehicle owner.
Terrace Park, OH
LANE DEPARTURE: ASSIST
Self driving assist, adaptive cruise , emergency braking assist do not work. Taken to dealer three times , unable to correct. Returned to customer with out paperwork documenting repair of safety systems. Problems are still in I repaired state. Emergency braking system warning message has activated 15-20 times after receiving car back. Other existing problems are still on going as well. Requested District service Manager consult the situation and advise. Love car , want to have repaired . Looking to add additional GLC to household . Hope repair is possible . ????! Hate to have accident, bad for health. Please contact. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
NHTSA complaint #11465447 — an unverified report by a vehicle owner.
Terrace Park, OH
LANE DEPARTURE: WARNING
Self driving assist, adaptive cruise , emergency braking assist do not work. Taken to dealer three times , unable to correct. Returned to customer with out paperwork documenting repair of safety systems. Problems are still in I repaired state. Emergency braking system warning message has activated 15-20 times after receiving car back. Other existing problems are still on going as well. Requested District service Manager consult the situation and advise. Love car , want to have repaired . Looking to add additional GLC to household . Hope repair is possible . ????! Hate to have accident, bad for health. Please contact. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
NHTSA complaint #11465447 — an unverified report by a vehicle owner.
Avenel, NJ
BACK OVER PREVENTION
The contact owns a 2020 Mercedes-Benz GLC300. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System). The dealer was notified of the recall and informed the contact that the recall repair would be performed over-the-air (OTA). The contact then called the manufacturer and was informed that the update was not available; he was informed that there was a waiting list and that he would receive a notification when the update for the vehicle was available. The contact had not experienced a failure. Parts distribution disconnect.
NHTSA complaint #11454089 — an unverified report by a vehicle owner.
WHILE DRIVING UNDER AN OVERPASS THE BREAKS ACTIVATED ABRUPTLY AND UNEXPECTEDLY. WE WHERE GOING ABOUT 35 MILES PER HOUR AND IF IT WASN'T FOR THE SEAT BELTS WE WOULD OF HIT THE WINDSHIELD. LUCKILY NO ONE WAS FOLLOWING US UP CLOSE.. IT HAPPENED TWICE AT THE SAME SPOT WHERE THERE IS A SHADOW FROM THE OVERPASS (AT SAME TIME OF DAY)
NHTSA complaint #11405472 — an unverified report by a vehicle owner.