Mercedes-Benz GLC-Class Complaints

782 consumer complaints on file.

#11742067June 4, 2026
ELECTRICAL SYSTEM
The instrument cluster display went dark and has not been able to display any information such as speed in miles per hour, fuel gauge, and other important information needed to maintain safe driving.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741752June 3, 2026
ENGINE
While driving the vehicle the engine started running rough, check engine light illuminated and it would not accelerate above 40 mph. There are 29,100 miles on the vehicle, it's been serviced on schedule by Mercedes and is owned by me since new. It is especially concerning due to the acceleration topic which could have been catastrophic if I were trying to merge into traffic. Dealer service say the camshaft bearing needs to be replaced. It seems this is very premature for the mileage on the vehicle.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741952June 3, 2026
ENGINE, POWER TRAIN
Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total repair estimate of $9,851 to perform extensive engine work. Safety Risk: This known manufacturing defect involves premature failure and cracking of the pistons, which poses an immediate safety hazard due to potential catastrophic engine failure and sudden, complete loss of motor power while driving at highway speeds. The manufacturer has failed to offer an extended warranty or recall for this known issue on the 2018 model year.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740380May 27, 2026
POWER TRAIN
While driving my 2024 Mercedes-Benz GLC 300 on California highways, the vehicle has repeatedly experienced sudden uncontrolled deceleration, unexpected transmission downshifts into 2nd gear, severe transmission jerking, and complete loss of accelerator response. The first major incident occurred on March 7, 2025, while traveling on Interstate 5 at approximately 70 mph. The transmission suddenly jolted and downshifted directly into 2nd gear. The vehicle immediately lost power and slowed to approximately 20 mph without warning. I exited the highway and restarted the vehicle before it temporarily resumed normal operation. A second major incident occurred on May 7, 2026, while driving on Interstate 5 near Flag City, California at approximately 65 mph. The vehicle suddenly decelerated uncontrollably to approximately 20 mph. The transmission again shifted directly into 2nd gear, and the accelerator pedal became completely unresponsive. I was forced to make an emergency stop on the shoulder of the freeway with hazard lights activated due to the risk of being rear-ended by high-speed traffic and trucks. A third incident occurred on May 13, 2026, while accelerating onto Highway 99 in Modesto, California. During a shift from 4th to 5th gear, the transmission jerked violently and the vehicle suddenly lost power while merging into highway traffic. The vehicle has been taken to Mercedes-Benz of Stockton multiple times for diagnosis and repair attempts. The dealership has performed software updates and extensive testing, and dealership personnel have personally verified the transmission defect during road testing. Mercedes-Benz engineering has also become involved in the diagnosis process. However, the defect remains unresolved. This defect creates a serious highway safety hazard due to sudden loss of propulsion, uncontrolled deceleration, and loss of accelerator response while driving at freeway speeds.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11739133May 20, 2026
ENGINE
While driving in my neighborhood at 25 MPH, my Mercedes GLC300 suddenly lost power and the check engine light illuminated. My car would no longer exceed 25-30 MPH, but I drove it straight to the dealership and they said it was a faulty cylinder head and will cost $10,000 to fix! After intense negotiations, they agreed to fix it for $4,205.58, which was better, but still, that’s a lot to pay for a manufacturer’s defect! My car is a 2021 with only 67,540 miles on it.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11738448May 18, 2026
ELECTRICAL SYSTEM, ENGINE, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
every time I get into my vehicle, I have a new malfunction that pops up and when I take it to the dealership they can never find what’s wrong. I have had multiple instances where my screen will turn black and there’s nothing I can do or the screen will freeze, and I can’t figure out how to get it back on. I can’t figure out how to get CarPlay to automatically connect to my phone because the vehicle is so jacked up. It’s been in the shop probably about 13 times since I’ve gotten it last December and has been in collision for six months now from someone rear ending me. every time collision calls me to pick it up and says it’s fixed it’s not fixed.
Crash:
Yes
Fire:
No
Injuries:
0
Deaths:
0
#11738083May 15, 2026
UNKNOWN OR OTHER
All screens on dash were black and a clicking sound could be heard I side the vehicle. This has happened four times. Towed vehicle to MB dealer and they did a software update but it keeps happening anyway.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11737705May 13, 2026
ENGINE, FUEL/PROPULSION SYSTEM, POWER TRAIN
I have had my car for almost two years. This problem has been on-going the whole time. It happens intermittently, I never know. I will be driving it and usually when I am making a turn or pulling onto a main road, you press the gas to go and the car hesitates and makes a loud brooooooooom sound like it is trying to go or figure out what to do and if you are pulling out onto a main road with on comming traffic, this is dangerous. We have seen information that on the 2019 and 2018 GLC300's this has been documented, my car is a 2020 but it's the same thing. It's like the car hesitates and slows down when it should go!
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11737239May 12, 2026
ELECTRICAL SYSTEM, STRUCTURE:BODY:HATCHBACK/LIFTGATE
In multiple incidents, the tailgate has begun to close while I am loading or unloading items from the trunk, hitting me in the head. My natural reaction is to lift up, causing injury to my neck. The dealer unsuccessfully "fixed" the problem. Additionally, and unrelated to the closing problem, on multiple occasions, upon pushing the close button on the tailgate when it was in an open position, the tailgate reaches the floor of the trunk, then without locking, opens about one (1) foot. The dealer "could not duplicate" the problem. I have to manually close the tailgate. You ask when did this happen, the latest incident is the date reported below, but the two issues/problems have reoccurred time and time again since we bought the vehicle new.
Crash:
No
Fire:
No
Injuries:
1
Deaths:
0
#11736466May 8, 2026
ELECTRICAL SYSTEM, ENGINE, FUEL/PROPULSION SYSTEM
Low coolant warning came on. Battery car didn’t start , had it jump. Low coolant warning came on again. Passenger seat belt warning is on.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11736573May 8, 2026
STRUCTURE:BODY:HATCHBACK/LIFTGATE, VISIBILITY:REARVIEW MIRRORS/DEVICES:EXTERIOR, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
My 2024 Mercedes-Benz GLC 300 has experienced multiple serious safety-related malfunctions involving several vehicle systems. In August, after picking up the vehicle from service, I placed my [XXX] grandson in his car seat, set my purse with the key inside the vehicle, and closed the rear door. The vehicle immediately locked all doors on its own, trapping my grandson inside in approximately 88-degree temperatures. I was unable to gain access for about 30 minutes. This created a dangerous child safety situation. Key fob periodically will lock you out of car. The following day, while driving approximately 35 mph with my [XXX] grandson in the vehicle, the car suddenly and violently applied the brakes and tightened the seatbelt without warning or any obstacle present. The vehicle came to a complete stop in the roadway. I later experienced bruising and increased neck pain afterward. I have also experienced repeated power liftgate malfunctions. While loading groceries, the liftgate failed to recognize my presence and closed on me unexpectedly, striking my head. The vehicle was brought in for service in November regarding this issue. Additionally, while driving on the highway, both side mirrors have suddenly folded inward without warning on several occasions, causing immediate loss of visibility and creating a serious driving hazard. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11736668May 8, 2026
ELECTRICAL SYSTEM, STRUCTURE:BODY
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)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11736351May 7, 2026
POWER TRAIN, ELECTRICAL SYSTEM
On April 16, 2026, within minutes of being released from a certified dealership, my 2019 Mercedes-Benz GLC 300 suffered a sudden and total loss of propulsion while traveling at high speed on the Belt Parkway (NY). Despite depressing the accelerator, the vehicle failed to maintain speed and stalled in active traffic. This created an immediate life-safety hazard, forcing me to navigate across multiple lanes without engine power to avoid a high-speed rear-end collision. The vehicle was released to me by Mercedes-Benz of Brooklyn on April 16, 2026, following a repair for which I paid $2,134.94. The dealership diagnosed the issue as a wiring harness/sensor fault and formally certified the vehicle as "Found OK" and safe for operation. The catastrophic failure occurred only 22 minutes after I departed the dealership lot. The vehicle had to be towed back to the facility immediately. Upon the vehicle being towed back on April 16, the dealership admitted via recorded voicemail that the initial $2,134.94 repair was a misdiagnosis. They subsequently issued a new diagnosis for a "Valve Body" failure and a new quote of $6,424. The dealership's Service Director has since admitted the vehicle suffers from concurrent transmission and engine failures, rendering the car a liability. This represents a critical failure of the powertrain and electronic control systems. Releasing a vehicle that suffers a total power loss on a highway immediately after a "certified" repair is gross negligence. I am reporting this to NHTSA as a catastrophic failure of a safety-critical component (Transmission/Valve Body) that resulted in a "dead-stick" situation on a major New York thoroughfare, posing a severe risk to myself and other motorists. The vehicle remains at the dealership. Mercedes-Benz USA has offered only a $2,000 "goodwill credit," which does not address the safety defects or the initial misdiagnosis. No recall has been initiated for this batch.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735862May 5, 2026
ENGINE
Getting P06DA trouble code meaning that there is something wrong with the oil pressure solenoid in the oil sump. this is a known issue where the wiring of the solenoid get frayed. cost of repair for the (cheap part) is $7,500 because of 18 hour labor involved. MB knows this is an issue with the wiring in the solenoid. I'm not sure if there is a fire risk because of the frayed wires.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735471May 4, 2026
ENGINE, ELECTRICAL SYSTEM, LANE DEPARTURE: BLIND SPOT DETECTION
The contact owns a 2025 Mercedes-Benz GLC 350E. The contact stated that while driving approximately 60 MPH, the vehicle began decelerating, losing drive power till the vehicle stalled. The contact turned on their hazards and had the vehicle towed to the dealer. The Check Engine, Blind Assist, Exit Warning Inoperative, Towing Not permitted, with several other warning or failure lights illuminated. The failure occurred twice. The dealer diagnosed that the ignition unit had failed. The vehicle was repaired; however, the failure occurred again. The vehicle was returned to the dealer diagnosed that the motor for the instrument panel had failed and needed to be replaced. The vehicle was repaired, but the contact was not sure if the failure was resolved. The manufacturer was informed of the failure, and a case was opened. The failure mileage was approximately 10,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735596May 4, 2026
STEERING
The steering tilt motor is stripped and will not move up or down and is stuck in the full "UP" position. Unable to adjust for the driving position.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11735615May 4, 2026
FORWARD COLLISION AVOIDANCE, STRUCTURE:BODY:HATCHBACK/LIFTGATE, ELECTRICAL SYSTEM
The contact owns a 2024 Mercedes-Benz GLC 300. The contact stated that while driving at approximately 35 MPH, the brake was applied unexpectedly without the contact depressing the brake pedal. The contact stated that she was unsure if the forward collision system was turned on at that time. The driver's seat belt tightened, and she sustained a bruise on her left arm and soreness on her chest. Medical attention was required. The vehicle was taken to a dealer where they were not able to replicate the failure. On another occasion, while parked, the tailgate was opened as groceries were being loaded into the rear cargo area. The tailgate closed inadvertently and struck the contact's head. The contact sustained head and neck injuries, and medical attention was required. The vehicle was taken to a dealer where the failure was not able to be replicated. The manufacturer was notified of both failures and advised that the automatic tailgate closing feature could be removed from the vehicle. The failure mileage was 31,153
Crash:
No
Fire:
No
Injuries:
1
Deaths:
0
#11733932April 27, 2026
UNKNOWN OR OTHER
I purchased a new Mercedes Benz GLC300 2023. Last month, my friend and I were driving on I75 in Florida when we heard what sounded like a loud boom or gunshot. We quickly discovered that my sunroof had exploded. The sunroof was closed, and fortunately so was the sunshade, as large pieces of glass flew off the roof and smaller shards of glass collected on top of the sunshade. My friend and I were fortunate to have not been insured and were able to safely navigate the vehicle to the side of the road to assess the damage. In contacting the MB dealership, I learned that the sunroof is considered "glass" and thus not covered under warranty even though the vehicle is only 3 years old with less than 50,000 miles. What is more concerning to me is that the roof was not under a recall, and there have apparently been other MB owners that have experienced the same issue with class action lawsuits pending. My insurance company covered the repairs following payment for the deductible. This huge safety concern is that we could have been seriously injured by flying and/or falling glass. I write to express my deepest concern over the safety issue the exploding roof presents-the cost of repair relative to what could have happened is minor. Thank you for the attention to this matter.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11733775April 25, 2026
SERVICE BRAKES
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11732752April 21, 2026
UNKNOWN OR OTHER, ELECTRICAL SYSTEM
Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This malfunction occurs without warning while the vehicle is in motion, creating a dangerous visual distraction for the driver and uncertainty of where and when to turn or exit. This is a known, recurring issue. On January 7, 2021, I brought this problem to Mercedes-Benz of Indianapolis (Repair Order #624027), where a firmware update was applied and the issue was allegedly resolved. The fix has not proven permanent — the problem has since recurred and continues to present a safety hazard while driving. Despite this being a widely documented issue affecting numerous Mercedes owners, Mercedes-Benz has not issued a recall or technical service bulletin that I am aware of. My dealer is requiring a diagnostic fee of over $250 to inspect the vehicle, and Mercedes-Benz USA customer service has been unreachable. Requested Action: I am requesting that NHTSA investigate this issue and consider whether a Technical Service Bulletin or recall is warranted given the safety implications of a sudden display malfunction while driving.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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