Home · 2026 Mercedes-benz GLC 300 4matic · Complaints

What 7 owners told NHTSA about the 2026 Mercedes-benz GLC 300 4matic

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.

All (7)Crash / fire / injury (1)Electrical system (4)Engine (2)Backup camera & sensors (1)Body & structure (1)Brakes (1)Steering (1)Transmission & drivetrain (1)Wheels (1)

4 of 7 complaints match · Electrical system · clear filters

Jun 17, 2026Electrical system

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 ODI 11744725

Jun 11, 2026Electrical systemEngineFire

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 ODI 11743388

May 8, 2026Electrical systemBody & structure

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 ODI 11736668

Jan 16, 2026Transmission & drivetrainElectrical system

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 ODI 11711555

Working with the data? Download all 7 complaints as CSV · fetched from NHTSA July 13, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2026 Mercedes-benz GLC 300 4matic verdict →