2023 Mercedes-Benz GLC 300 Owner Complaints

My sunroof exploded while driving on the interstate.

NHTSA ID

11732486

Incident

Apr 17, 2026

The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while driving at an undisclosed speed, the speed limit warning system failed to function as intended. The contact stated that while driving 60 MPH, the Heads-up Display (HUD) illuminated a red light and an unknown message about driving too slowly was displayed. The contact stated that the red light illuminated and flashed intermittently. The vehicle was taken to the dealer, and the contact was informed that the failure was common with the vehicle. The vehicle was not repaired. The contact stated that the failure persisted. The contact asked if the speed limit warning system could be deactivated, and the dealer was informed that it had to be approved by the manufacturer. The manufacturer was made aware of the failure. The contact was referred to the dealer for assistance. The contact stated that the dealer and the manufacturer offered no assistance. The failure mileage was approximately 12,000.

NHTSA ID

11725658

Incident

Jan 9, 2023

Mileage

12,000 mi

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 ID

11725254

Incident

Mar 18, 2026

I purchased a brand new GLC 300 on May 25, 2023. By June 2, 2023 I was already stranded due to a 12V battery electrical system failure. Since then I have been stranded 8 total times and the vehicle has been in the service department 14+ times for repeated electrical issues (8 of those visits were related to the same 12V battery electrical system failures. The battery was reportedly replaced in 2024-shortly thereafter I began experiencing issues with the collision assist malfunctioning. The alarms would sound seat belt tighten and brakes lock up while driving on the interstate. The theft deterrent alarm wound sound in the middle of the night without provocation. The panoramic roof would malfunction. The air vent disintegrated. In August 2025, the collision assist malfunctioned causing the vehicle to steer off the road resulting in a blow out. It has not been driven since.

NHTSA ID

11722368

Incident

Jun 2, 2023

Vehicle has a significant engine oil leak without being driven. Engine oil electronic meter still shows engine oil to be in "Ok" range. Vehicle is 2023 with only 19680 miles and is rarely driven till the last 2 months. Other 2023 Model Year MB GLC300's manufactured at the same Bremen Germany plant are already being recalled for engine and fuel leaks, however, this one is not on the list. This vehicle is also the 2.0L Inline 4 engine and may be the same engine as the others being recalled. The others are recalled due to an imperfect seal between the high pressure fuel pump and the tandem oil pump. My vehicle is leaking engine fluid, likely oil at a significant rate without having been driven in any unsafe manner or much use.

NHTSA ID

11685600

Incident

Sep 3, 2025

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 ID

11653863

Incident

Mar 2, 2025

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 ID

11644659

Incident

Feb 24, 2025

Mileage

12,000 mi

check engine light continues to turn on and off, response from dealer maintenance is this issue is temperature related and just keep driving, not sure how this makes for an effective or safe functioning of a warning light also seems like it can lead to unnecessary trips to and costs at the maintenance garage. This has been a multiple time issue since purchase of vehicle.

NHTSA ID

11629834

Incident

Dec 3, 2024

The sunroof glass blasted and shattered during a drive on an interstate highway. I was driving normally when I heard a loud sound like a tire burst or gunshot. Initially, I thought that my tire had busted. I took an exit and stopped to inspect the tires. I found them to be okay, but I was puzzled where the sound came from. I started driving again and observed that a lot of outside noise was coming, also there was a glass clinking noise so I stopped again to check. I found a hole in my sunroof and the shattered glass had fallen on the protective mesh cloth. That is when I realized that the loud sound was from this broken sunroof. It was something like that the sunroof had blasted outwards as the bump was going outside. Luckily, I didn't lose control of that sudden, loud sound and didn't get into a crash. Hopefully, the broken glass didn't fly and hit other cars.

NHTSA ID

11629650

Incident

Dec 6, 2024

Car has software issue putting drivers at risk until the update is provided. Response to problem from manufacturer is to drive the car or wait until such time as a solution is developed. this is the 3 issue in less than a year the car's fuel uptake system is interrupted putting drivers at risk when pulling out into traffic or needing normal acceleration expected from a normally functioning car. How long will Mercedes get away with this before someone is killed

NHTSA ID

11623589

Incident

Nov 4, 2024

See attached document for complaint.

NHTSA ID

11621247

Incident

Sep 27, 2024

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 ID

11618304

Incident

Jul 12, 2024

The care sends a message that the battery is low. Then the check engine light comes on till we drive the car for awhile. The first time this happened I took it to the dealer and they said they could find nothing wrong with it and was giving no readings. It has continued to happen a lot. The battery should not be going down if it not being used. There has to be a problem. This has been going on for over a year. The dealer where we bought the car called today about service and said there was a recall about the battery, but when I call MB they said there was not recall?

NHTSA ID

11615647

Incident

Sep 15, 2024

Loss of propulsion at highway speeds with subsequent failure of digital light system at night resulting in injury crash

NHTSA ID

11614976

Incident

May 9, 2023

Second time the rear left tail light not working properly. The parking light stay on after turning vehicle off at time it turns off. The light assembly was replaced by dealership less than a year ago. The light assembly was defective according to the dealership vehicle was purchase 10 prior.

NHTSA ID

11609329

Incident

Aug 15, 2024

The contact owns a 2023 Mercedes-Benz GLC 300 W4. The contact stated that when his wife was parking the vehicle at approximately 5 MPH and when she depressed the brake pedal, the vehicle stalled. The contact stated that his wife said that the brake pedal failed, and the instrument cluster was black. The contact stated that his wife had observed that the brake warning had been illuminated before the instrument cluster failure. The contact stated that his wife jumped the curb and crashed into the wall of a building. The contact stated that the front end of the vehicle was crushed, and the hood was damaged. The contact stated that the front headlights and front bumper were also crushed. The contact stated that the windshield was cracked as well. The contact stated that his wife was unhurt despite the air bags not deploying. The contact stated that the police were called and they issued a report. The contact had called his dealer who referred him to a body shop. The contact had the vehicle towed to a local body shop. The vehicle was not diagnosed by a dealer or independent mechanic. The vehicle damage was being repaired. The contact had researched online and related the failure to NHTSA Campaign Number: 24V115000 (Electrical System). The manufacturer was informed of the failure. The failure mileage was approximately 7,000.

NHTSA ID

11607936

Incident

Jul 11, 2024

Mileage

7,000 mi

There is an active recall for my vehicle Mercedez Benz GLC 300W4 for which I was NOT NOTIFIED BY THE DEALER AND MANUFACTURER. The recall states that certain 80A fuses installed might not meet production requirements. As a result, a contact interruption or an increased triggering resistance might occur. In this case, systems connected to the fuse might become inoperable. Among others, the vehicle might lose propulsion without warning, restraint functions or the instrument cluster might be impaired, increasing the risk of a crash and injuries. In addition, a risk of fire cannot be ruled out. An authorized Mercedes-Benz dealer will replace the respective main fuse box on the affected vehicles. The following is the SAFETY RISK associated with this recall. As a result, a contact interruption or an increased triggering resistance might occur. In this case, systems connected to the fuse might become inoperable. Among others, the vehicle might lose propulsion without warning, restraint functions or the instrument cluster might be impaired, increasing the risk of a crash and injuries. In addition, a risk of fire cannot be ruled out. I have noticed that check engine light turning on at times while driving which might be due to this fuse malfunctioning. Please take appropriate action and support my case. I can provide more details if required. Thank you.

NHTSA ID

11601017

Incident

Jul 2, 2024

First of all, this is a new car produced in 2023. Since I bought it, the engine has shown alarms more than four times. Every time I went to the 4S shop, no problems were found. Today, the engine still shows a yellow alarm. Secondly, the brake disc makes a loud noise when I park the car and then start the accelerator. Mercedes-Benz has not paid attention to these problems. I think it greatly affects driving safety.This car has been sent to the 4S store many times, but the inspection has always failed. The above-mentioned problems with the car have always existed. I sincerely request your help in solving them.

NHTSA ID

11595907

Incident

Jun 22, 2024

The automatic windows open when the car is parked without being initiated by anyone. Think of it as phantom window opening. The vehicle occasionally reports a window being open when in fact they are all closed. When the phantom opening occurs there is not notice of a window being open.

NHTSA ID

11591237

Incident

May 29, 2024

When working in the rear cargo area, the door comes down without warning and does not break when it meets resistance trapping me between the body of the car and the descending door. A great deal of physical pressure must be employed in trying to get it to reverse direction. It is a struggle to get out from under the continually closing door. This has happend to me on three different occasions. There should be an automatic reversal when the door meets resistance not unlike a garage door.

NHTSA ID

11591232

Incident

May 29, 2024

The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while he and his wife were loading the trunk of the vehicle, the trunk door independently lowered and struck his wife on the head. The contact stated that the failure occurred frequently. The contact stated that he had previously had a concussion and was concerned about being struck on the head by the trunk during the failure. The dealer was made aware of the failure, and the vehicle was diagnosed; however, the cause of the failure was not yet determined. The dealer informed the contact that the automatic open and close feature on the trunk could not be disengaged. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 10,000.

NHTSA ID

11586735

Incident

Mar 14, 2024

Mileage

10,000 mi

Vehicle would not start, indicator displayed check owners manual, battery low. Vehicle towed to dealer

NHTSA ID

11585120

Incident

Apr 20, 2024

The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while the vehicle was parked, and the contact and his wife were removing groceries from the rear of the vehicle, the tailgate was independently lifted due to the design of the keyless entry feature. The contact and his wife continued to remove items from the rear of the vehicle and the tailgate sensor became enabled, and the tailgate closed inadvertently, striking the contact's wife on the head. The contact's wife sustained a knot on the head that remained for a week. The vehicle was taken to the dealer. The contact was informed that the feature could not be deactivated unless the contact chose to deactivate the entire keyless sensor feature. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure and the contact was informed that the option would be to deactivate the entire keyless sensor. The failure mileage was approximately 1,000.

NHTSA ID

11580776

Incident

Aug 23, 2023

Mileage

1,000 mi

On [XXX], I was driving at 45MPH on a two-lane state road. There was no traffic within 1/4 -1/2 mile of me on that road. There were no guardrails and the road was clear - no birds, animals, people, or construction. For no reason, the car beeped twice and automatically slammed on the brakes so forceful that everything on a seat landed on the floor. Had there been a vehicle behind me, they would have almost certainly slammed into me. This is my second safety report with this vehicle, the previously reported lane keeping assist still allows me to depart my lane with no correction or indication by the system, the dashboard indicators remain green if I depart my lane without a turn signal. It has been in 5 times for this and Mercedes closed the case. They say it's fine. Lemon law attorneys in my state refuse to take cases with Mercedes so I am stuck with a vehicle that should not be allowed on US roads, can't lemon law it and can't sell it or trade it in with a clear conscience. There is a laundry list of other problems as I drive more than 25,000 miles a year but I only report those which could get myself or others killed. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11576799

Incident

Mar 11, 2024

Vehicle sputter and coolant malfunction and engine light came on while driving ( 12-26-23) Took to dealer for some “ update”. After a few weeks of driving the vehicle sputter again and engine light came on again on the (1-19-2024 ) Drove home turned off , loud noises came from engine area. Tried to restart and failed a few times so we let it’s sit for almost an hour and it’s started again with engine light still on . Towed to Mercedes dealer and after long and frustrating times a week later per dealer it’s was the 48v hybrid battery that defective/ non functional. So far we been forced to drive the vehicle “as is” since Mercedes-Benz USA refused to let local dealer to order and replace the 48v hybrid battery. It’s been 2 weeks all informations we get from dealership is that we have to wait for Mercedes to come up with new software to update to which no time frame have been provided as to when software available. We’re experiencing terrible gas mileage MPG with the 48v battery basically non functional as moment

NHTSA ID

11569863

Incident

Dec 26, 2023