54 of the
609 complaints filed about the Mercedes Benz GLC 300
are about the driver-assist systems —
9% of everything owners reported.
The worst model year for it is 2020.
54
Complaints
9%
Share of all complaints
8
Crashes
0
Fires
Driver Assist & Collision Avoidance complaints by model year
There are two issues 1) Unsure of the exact date, but about a year or two ago we were driving our car and the car's automatic break system went into effect on a typically busy, 3 lane road despite there not being any cars in front of our vehicle. We took it into the dealership, who confirmed the issue and told us that sometimes the automatic brake mis-identifies the metal plates in the roads to be vehicles. Had there been a car driving behind us at the time this was happening, it could have been a major accident as the speed limit on that road was 45mph. Additionally we had our [XXX] in the car. There were no warning lamps, messages or symptoms of the problem prior to failure. 2) Recently we have been having a warning sign on our car that says the 12v battery is low, even though it should not be. Historically this would tell us to drive our car around so the battery wouldn't die, but this would sometimes turn on even after a 30+ minute drive. It was turning on every single time we turned the car off, so we brought it into the shop. While in the shop, the dealer provided us with a brand new GLC 300. I took this GLC 300 to my son's daycare to drop him off and when I returned to the car I received an error message "48V battery service required" and could not turn on the vehicle. This brand new vehicle left me stranded. While I was safe at my son's daycare, this has caused me to have significant concerns around the safety and reliability of these GLC300s. We are planning on taking our 2023 GLC 300 on a 6 hour road trip with our [XXX] old and [XXX] old and I am very concerned about the car not starting if we stop for gas. What if we get stranded in a small city along the way? INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11725254 — an unverified report by a vehicle owner.
The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that the rear-view camera was not functioning properly. After restarting the vehicle, the camera operated as needed; however, several days later, the camera became inoperable. The contact referenced NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System); however, the VIN was not included in the recall. The dealer was not notified of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 96,000.
NHTSA complaint #11724158 — an unverified report by a vehicle owner.
I was involved in a severe front-end collision where my vehicle struck another vehicle with significant force. Despite the major impact, the front airbags did NOT deploy. The entire front end of the vehicle was crushed, including destruction of the radiator, damage to engine components, internal structural collapse, and leaking fluids. Based on the severity and direct frontal nature of the crash, airbags should have deployed but did not. As a result of the impact, I sustained a neck and upper shoulder injury and required medical evaluation. There were no warning lights or messages prior to the crash indicating any malfunction in the airbag or SRS system. The vehicle is available for inspection by NHTSA, the manufacturer, insurance, or an authorized Mercedes-Benz service center. This appears to be a possible failure of the airbag/SRS system during a qualifying collision.
NHTSA complaint #11699636 — an unverified report by a vehicle owner.
The rearview camera on my vehicle intermittently fails to function for unknown reasons, and the problem has recently become more frequent. For example, it may work normally when I first start the car in the morning and back out of my parking spot, but later the same day—such as when I arrive at work—the camera stops working completely. The display stays black and does not recover even after shifting between gears or restarting the system. After parking and locking the car for a while, the camera may start working again without any clear reason. Although I cannot recall the exact dates of the first occurrence, I have noticed a consistent pattern over time: the issue tends to appear during hot weather, particularly in summer. In recent months, the camera has almost completely stopped functioning. This unpredictable failure creates a potential safety hazard when reversing, as I cannot get help on the backup camera to provide visibility behind the vehicle.
NHTSA complaint #11698047 — an unverified report by a vehicle owner.
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.
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.
The brakes did not function at all. Upon trying to brake, the brake pedal was hard and the car would not stop. The car went into s storefront where the cashier is located and could have resulted in serious injury or death to anyone waiting to pay at the store. The forward collision alarm did not sound, the dashboard indicator for an impending forward collision did not illuminated. The car did not slow down or stop to avoid the collision. The car is currently at the body shop.
NHTSA complaint #11684967 — an unverified report by a vehicle owner.
The brakes did not function at all. Upon trying to brake, the brake pedal was hard and the car would not stop. The car went into s storefront where the cashier is located and could have resulted in serious injury or death to anyone waiting to pay at the store. The forward collision alarm did not sound, the dashboard indicator for an impending forward collision did not illuminated. The car did not slow down or stop to avoid the collision. The car is currently at the body shop.
NHTSA complaint #11684967 — an unverified report by a vehicle owner.
The contact owns a 2025 Mercedes-Benz GLC300. The contact stated that while driving approximately 30 MPH, there was an abnormal grinding sound coming from the vehicle. The contact stated that the brake assist suddenly activated and the vehicle came to an abrupt stop, causing the seat belt to immediately retract and lock. The contact was slightly jerked from the abrupt stop. The contact stated that a warning light with a red triangle with an image of a crash in the center was illuminated. The contact stated that after starting the vehicle, the infotainment center and the instrument panel were completely black. The vehicle was restarted several times before both systems started operating as needed. The failure occurred twice; however, the second time, the contact had to turn off and restart the vehicle for approximately an hour before the infotainment center and instrument panel became operational. The vehicle was taken to the dealer, who performed a software update for the infotainment center. After the software update was completed, the contact became aware there were other electrical systems that failed intermittently, including the voice activation system. The vehicle was returned to the dealer and the contact was informed that the front driver’s and passenger’s sides sensors were too low and there was no reason for the notification to become activated. The vehicle was not diagnosed or repaired. The manufacturer was informed of the failure, and a case was opened. The failure mileage was approximately 2,000.
NHTSA complaint #11683653 — an unverified report by a vehicle owner.
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.
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.
1. Rear Hatch hands free system - closes unexpectedly while loading or unloading car without using feet to trigger system. Hatch will close down and trap driver in the rear, causing bruising on driver and requiring assistance to push hatch back up. Has been into dealer multiple times since this is HUGE risk to animals or small children exiting out of the rear. Dealer finally disabled hands free system. 2. Lane change assist/blind spot warning - Auto believes there's a vehicle in the lane to either side and will stop car from changing lanes, when actually there isn't a vehicle there. Has caused several close calls due to signaling to change lanes the car will then try to pull back into previous lane. Warning light remains on the side mirrors even when there are no vehicles in the lane. This is especially hazardous while driving at night and in less than optimal weather conditions.
NHTSA complaint #11653863 — an unverified report by a vehicle owner.
1. Rear Hatch hands free system - closes unexpectedly while loading or unloading car without using feet to trigger system. Hatch will close down and trap driver in the rear, causing bruising on driver and requiring assistance to push hatch back up. Has been into dealer multiple times since this is HUGE risk to animals or small children exiting out of the rear. Dealer finally disabled hands free system. 2. Lane change assist/blind spot warning - Auto believes there's a vehicle in the lane to either side and will stop car from changing lanes, when actually there isn't a vehicle there. Has caused several close calls due to signaling to change lanes the car will then try to pull back into previous lane. Warning light remains on the side mirrors even when there are no vehicles in the lane. This is especially hazardous while driving at night and in less than optimal weather conditions.
NHTSA complaint #11653863 — an unverified report by a vehicle owner.
I am experiencing auto braking when there are no obstructions near or around the vehicle. The auto braking is random but occurs fairly often. It is very unsettling and makes me very nervous while driving my brand new vehicle. This happens without warning and can definitely put myself and my passengers as well as passengers in the vehicles around me at great risks of collisions.
NHTSA complaint #11645213 — an unverified report by a vehicle owner.
The contact owns a 2023 Mercedes-Benz GLC 300. The contact stated while driving on an access road at 35 MPH, the brake pedal was not depressed; however, the vehicle came to an immediate stop. There were no warning lights illuminated. The contact restarted the vehicle and was able to continue driving normally. The local dealer was contacted and sent a tow truck to pick up the vehicle from the residence for diagnostic testing. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 12,000.
NHTSA complaint #11644659 — an unverified report by a vehicle owner.
While slowly backing out of the driveway and without contacting anything at all, the rear window completely shattered. The window has never been hit by anything and had no defects yet it completely shattered so clearly reflects a manufacturing defect of some sort that is incredibly dangerous to passengers or other vehicles, since it happens without warning and without the necessity of an impact of any kind.
NHTSA complaint #11641925 — an unverified report by a vehicle owner.
The reverse sensors are faulty, causing the GLC300 model to randomly auto-brake while going in reverse. My driveway is flat and long with no significant grade changes and this has occurred at another location as well with similar topography. There are no obstructions present nor any significant grade changes, the vehicle auto-brakes not everytime, happens out of the blue once every 8-12 tries. My new vehicle has been checked out by Mercedes-Benz of Cary service department 2 times, since buying new April 2024. They brought my car out to my house themselves and experienced the auto-braking first hand. They brought out a second GLC300 and it auto-braked as well. The technicians have calibrated, and updated the sensors to no avail. My driveway is long and flat with a slight slope at the end, but it happened to me at my friends house who's driveway is all flat. This is a serious safety risk for me and all passengers. It makes everyone tense not knowing next time it may happen. No matter the revering speed, or if you keep your foot on brake lightly as you are backing up, the glc300 randomly will auto-brake without any warning lights or sounds. The tires screech, it locks up in an instant. It is frightening and we are scared to anticipate the next occurrence or risk bruising our body or head injury. Even when I manually over-ride the rear and/or surrounding sensors, turning them off temporarily as I back up in reverse- the car will still auto-brake. Mercedes has yet to agree with me that this is a safety issue and on 11/8 asked me to pick up the car. I refused until the issue is fixed. They still have my car in service, it has been 3 weeks since 10/18/24. This was the 2nd time I brought in in for this issue since I bought new March 30 2024. I called corporate to ask them to buy back the car if the issue cannot be fixed, they have yet to respond.
NHTSA complaint #11624989 — an unverified report by a vehicle owner.
GLC 300 was purchased new on May 25, 2023. Multiple 12V battery errors, check engine indicators, and rear hatch closing on owner starting the first week of ownership. 48V battery and Main Fuse Box were replaced. Multiple recalls were addressed. Most significant issue related to false collision avoidance incidents on two occasions that resulted in dangerous situations and extreme stress on the occupants. First occurrence was on July 12, 2024. Driving approximately 40 mph on two lane road near a school that was not in session. There were no surrounding vehicles, pedestrians or obstacles. Vehicle beeped, seatbelts locked, and speed forced to 10 mph. Took vehicle to local MB dealership who attributed the vehicle’s response to proximity to a school zone. Vehicle was not checked for fault codes. Second occurrence was on August 19, 2024. Driving 55 mph on major highway and a truck entered the merge lane to the right. The truck was travelling at reduced speed and remained in the merge lane showing no effort to merge into vehicle’s lane. Vehicle had violent sudden deceleration with beeping alerts, locking seatbelts and reduced speed to 10 mph. Driver and passenger experienced symptoms of whiplash. It was fortunate that there was no vehicle travelling immediately behind the vehicle. Vehicle was driven to MB dealership for analysis. The vehicle had been driven 6,177 miles in 15 months. Service manager indicated there were no fault codes so no maintenance was warranted. Owner viewed the vehicle as dangerous due to false collision avoidance issues that put passengers and others at risk. The owner sold the vehicle to the MB dealership.
NHTSA complaint #11618304 — an unverified report by a vehicle owner.
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.