2026 Mercedes-Benz GLC 300 4MATIC Owner Complaints

The contact owns a 2026 Mercedes-Benz GLC 300 4MATIC. The contact stated that her instrumental panel was not working, which caused her to be unable to see the gas level, oil, thermostat, and any warning lights. The vehicle was taken to a dealer twice. The first occasion the vehicle's instrumental panel was repaired. The failure reoccurred. The vehicle went back a second time, but was not repaired. The manufacturer was notified of the failure. The failure mileage was 5,769.

NHTSA ID

11744725

Incident

May 1, 2026

Mileage

5,769 mi

I was parked for a few minutes and I suddenly noticed a strong oder coming into my vehicle. I could not pinpoint what the smell was, but I knew that whatever was coming into the SUV was not safe. My screen started flashing warnings "Service Required: Do Not Drive" “Do Not Shift Gears”. After the warning, white smoke started to roll out from under the hood and into the vehicle. I immediately ran back to get my baby out of her car seat and to safety. I was at my local YMCA and staff ran out to I assist me and had a fire extinguisher. YMCA called the police and fire department. Both were dispatched to the scene. I called my husband for help while we waited for police & fire to arrive. My husband popped the hood and we saw large blue flames coming out from the transmission or the engine and we notice that transmission fluid started to leak under the vehicle. My husband put the fire out with the fire extinguisher. A police report was made. I contacted the dealership immediately. I contacted my auto insurance agent the next morning. The fire dept. used heat guns to test the heat level in the engine area. Prior to this, I did not have any issues with the vehicle. I believe this to be some type of mechanical or electrical malfunction or failure, based on the white smoke and blue flames. My daughter and I were put at extreme safety risk. If my husband and the YMCA staff did not assist, I feel that we would have lost our lives. With the large amount of smoke rolling into the air, children entering & leaving the YMCA were exposed to smoke/oder. Police had the vehicle towed to a tow lot near by to await Mercedes to pick up the vehicle and tow it to the dealership that I got the car from, so that it can be inspected. That was on 06/01/26. It is now 06/11/26 and Mercedes has not picked up the vehicle from the tow lot as they had confirmed that would be taking care of it.

NHTSA ID

11743388

Incident

Jun 1, 2026

I bought a 2026 GLC300 4matic SUV a month ago. I am very disappointed and scared of serious bodily damage due to the trunk door closing by itself while my upper body is loading/unloading the trunk. My wife and I were hit on the shoulder, back, arms, or head over a dozen times for 1 month. We took the car to the dealership for the problem but did not hear back from them for 3 days. The loaner car the dealership provided which is also 2026 GLC300 SUV also closes on me in the trunk. When the trunk shuts by tself while part of my upper body is in the trunk, it is impossible for me to stop it. It requires the 2nd person to stop the trunk door by forcefully pushing up. If I am alone, I don't know what could happen to me when tailgate closes on me. I have never had this problem with my old 2018 GLC300 4matic SUV for 8 years that has been traded-in to purchase this 2026 GLC300 4matic SUV. It turned out that the same problem has been discussed in the Mercedes GLC Forum with 19 participants, as shown in the link below: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11736668

Incident

Apr 30, 2026

The breaks on these vehicles are extremely dangerous . Before I leased this vehicle test drove 3 vehicles. The salesman said the breaks will adjust as you drive. They have not. ITS all over the internet that this vehicle has very unresponsive breaks. It takes 75 precent of pressure pushing down on the break pad distance before the car breaks engage. I already almost had an accident as the distance it takes for the car to respond is a significant distance before the car comes to a full stop. I have brought back the car to my dealership three times expressing my displeasure and each time I m told there is nothing they can do unless a fix comes from the manufacture. They said I'm not the first to complain about these dangerous breaks. What will it take for Mercedes to address this issue before someone gets killed. I hope there is someone at the NHTSA that will take the initiative to contact Mercedes and get them to address this very unsafe defect on these model cars. I thank you in advance.

NHTSA ID

11733775

Incident

Apr 17, 2026

While at a stop with foot on brake, the vehicle surges forward powerfully making a loud noise despite having foot on brake. Forcefully pushing on brake pedal harder eventually stops the car. Most recent time the display screen showed "Transmission Deactivated". Dealership drove car once but did not perform service inspection. Dealership to pick up/tow vehicle for service inspection. This happened four times in the eight weeks since pick up of vehicle as brand new. This could have cause a crash or caused vehicle to strike an object or person. Vehicle accelerated on its own and was difficult to stop.

NHTSA ID

11711555

Incident

Jan 16, 2026

Backup camera keeps opening and closing constantly while driving in slow speeds. While driving, backup camera keeps opening and closing, creating a noise and distraction to the driver and might cause accidents. The issue has been confirmed by the Mercedes Benz dealership service manager, describing as a recurrent in specific models with no current action plan or solution on near future. The car and component has been checked by the manufacturer. There are no warning lamps or symptoms prior to the problem occurrence and appeared at the first couple of days driving the car out of the dealership.

NHTSA ID

11710801

Incident

Dec 3, 2025