2020 MERCEDES-BENZ GLC-Class Problems & Complaints
Real owner complaints and problems reported to the National Highway Traffic Safety Administration (NHTSA). View common issues by component.
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Complaints Reported
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Complaints by Component
ENGINE
15 complaints
The engine in my 2020 Mercedes-Benz GLC 300 suddenly malfunctioned while driving on two separate occasions. The vehicle began shaking violently and lost power without warning. I could not accelerate and had to pull over immediately. I turned the vehicle off and restarted it to regain limited driveability. On the second incident, the power loss was so abrupt that it felt as if I had been rear-ended. I feared the vehicle would stall in traffic and cause a crash. Following these events, the check engine light remains constantly on. The dealer inspected the vehicle and confirmed excessive valve leakage into the exhaust system, requiring a complete cylinder-head replacement. They warned the failure will worsen and could result in sudden power loss again. This defect poses a serious safety risk. If the power loss occurs while merging or at highway speeds, it could easily lead to a rear-end collision. The vehicle has relatively low mileage for such a severe internal engine failure, and I have learned that other owners of this same engine have reported similar issues. Sudden stalling or loss of acceleration places occupants and other drivers in danger. There were no warning messages prior to the failure, and the problem has recurred. The vehicle is available for inspection, and the defect has been confirmed by a Mercedes-Benz service center. This appears to be a mechanical defect in the engine design, potentially involving valve seat failure. An investigation is needed to determine if this issue is widespread and whether a recall or manufacturer action is required to prevent accidents or injuries.
Dec 08, 2025
My 2020 Mercedes-Benz GLC 300 experienced a complete engine failure at ~51,000 miles, shortly after a major repair for a known defect. Initially, the vehicle showed a misfire on cylinder #3, which was diagnosed at RBM of Alpharetta as low compression due to valve seat damage, matching MB TSB LI01.30-P-072328. The cylinder head was replaced in Aug 2025. About two months later, while driving under normal conditions, the vehicle made a loud cranking/knocking noise and completely stalled in traffic without any check engine light or warning. This sudden stall posed a serious safety risk. The vehicle was towed to the same dealer, who has now diagnosed the engine as fully seized and recommended a complete engine replacement. I had also completed the 50,000-mile scheduled service at the same dealer shortly before this failure. Despite this being clearly linked to a known design defect, Mercedes-Benz USA has declined to provide further assistance or goodwill coverage. I am reporting this to highlight both the mechanical failure and the safety risk—this engine seizure occurred without any prior warning lights and could have resulted in a crash. I believe this reflects a systemic failure with the M264 engine in GLC 300s, affecting vehicle reliability and road safety. MBUSA has not provided a written explanation for their denial. I am concerned this issue may affect other GLC 300 owners and deserves investigation or recall consideration.
Dec 03, 2025
I am the owner of a 2020 Mercedes-Benz GLC300 with the M264 engine. I am hoping that you can assist me with a widely reported, systemic defect: the premature failure of the master cylinder, regardless of vehicle mileage. This issue is extensively documented by numerous owners of the 2020 and 2021 GLC300 models across various public forums, including Reddit and dedicated GLC owner communities. I took my vehicle to Mercedes dealearship for annual service and an intermittent check engine light. The dealership informed me it was a spark plug issue. Once repaired the check engine light went on permanently and the car hesitated as if it would turn off. I brought my car in for service and was told that it was a master cylander failure of the engine. Known Defect: The defect is so widespread that it indicates a manufacturing or design flaw. Corporate Refusal: Mercedes-Benz corporate has failed to acknowledge this systemic issue publicly or initiate a recall. Local Acknowledgment: When engaging with Mercedes-Benz of Paramus, Service Manager Ben Wright acknowledged both the existence of the issue and Mercedes-Benz's corporate awareness of the defect, yet confirmed the lack of a formal recall. Repair Cost & Offer: Following the failure, I was presented with a $12,000 repair bill for parts and labor. The only offer of assistance from corporate was a minimal 20% discount, still forcing me to pay a final cost of $10,620 for a repair that should be covered under a mandatory recall. Unfortunately, I was out of warranty by 1 year and 8,000 miles. This refusal to address a known mechanical flaw is unacceptable, especially given the significant financial burden placed on owners for a defect acknowledged internally.
Oct 20, 2025
With approximately 57,500 miles, the car began idling roughly, misfiring and losing power. The dealership has diagnosed it with a cracked cylinder head which will require a replacement at a cost of $9,765.00. The dealership indicated this is a common issue with the M264 engine (rear wheel driver) in the GLC300 and the M260 engine (the front wheel drive version) has already had a service extension for 15 years/180,000 miles. This type of failure should not occur at this mileage or even significantly more.
Aug 06, 2025
•Jan 2025, while the car owner was driving her GLC300, a warning light came on, the car shook and then shut down. AAA tow truck suggested Green’s Garage as an approved nearby repair shop. Car was towed there and repaired for approximately $450.00. •[XXX], late afternoon, the same problem arose but the car did not shut down. The car owner drove the car home and the car was dropped off at Green's Garage (GG) on the morning of May 27. Late that afternoon, GG called us to tell us the problem is not related to the January repair…Even though the symptoms were exactly the same as January with the exception of the car not shutting down. GG later stated the new problem is related to the spark plugs and that the cost to repair would be about $450.00. We agreed. •The next day (Wednesday) late in the afternoon GG called us to tell us that they found an additional problem. One of the fuel injectors was leaking. To fix the fuel injector plus the spark plugs would cost about $1,300.00. We agreed. •The car owner picked up the car late Thursday afternoon. Nothing was fixed, the engine warning light immediately came back on and the engine shook, so we have formally disputed the $1,300.00 credit card charge with our bank. [XXX] took the car on June 4 at 9:00 AM to Mercedes of Coral Gables for a pre-arranged $360.00 diagnosis. On June 5 we were informed that the engine and transmission mounts collapsed for a repair charge of $2,518.00. Also, the cylinder head valve seats are leaking and need replacing for a charge of $11,757.00. Total $14,275.00. Mercedes Benz should pay for this. Our car is a 2020 model with only 63,000 miles, but the problems started at less than 60,000 miles. We have read that this problem with this engine has existed since 2024 or earlier and that Mercedes Benz refuses to acknowledge the situation or pay for the repairs. It is dangerous to drive this car. Mercedes should be held responsible for all repairs and and accidents caused by this malfunction. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Jun 06, 2025
+ 10 more complaints for this component
UNKNOWN OR OTHER
10 complaints
The front main light on the driver side stopped working after a rain and it continued getting moister in the head lamp every night until a few days ago and as a result the head light assembly does not work at all ,the same thing is happening on the passenger side front head light assembly except it is still working .research showed that this has been a problem on similar Mercedes Benz cars and considering that the car has not had any accidents to possibly causing this it was concluded that this should have been part of the recalls .car is not operatable and i reached out to Mercedes Benz and they acted like I am out of my mind and it is passed the express warranties with car having 69000 miles. I tried explaining to them about the implied warranty and the safety problem and they continued with the same none sense. at this point The MBZ dealers want over $ 6000.00 to replace the part and I am not able to operate car.what can you do for me and others effected.
Dec 19, 2025
While driving on the highway I began to hear an unusual amount of wind noise inside the car. I thought the sound was coming from the sunroof, though it was completely closed. I pushed the button to confirm it was sealed, but the noise continued. Shortly after, I heard a loud cracking sound followed by a sudden pop. I looked in my rearview and saw something flying but didn’t immediately recognize what it was. I pulled over to inspect the situation and discovered that the entire exterior trim panel between the windshield and sunroof had detached. Another driver, who had been behind me, also pulled over after being struck by the debris. Thankfully, there were no bodily injuries, but this incident could have resulted in a serious accident. A large, fast-moving piece of trim flying off a vehicle at highway speeds presents a significant danger to other drivers, especially if they try to swerve to avoid it. I took my car to a Mercedes-Benz dealership for inspection and potential repair. I informed the service advisor that I had seen documentation of a recall involving the same issue, detachment of the sunroof panel on vehicles of the same make, model, and year as mine. However, I was told that my vehicle was not eligible for the recall based solely on its VIN and that Mercedes would not cover the cost of repairs. This is not a typical wear-and-tear issue. Structural components of a car should not randomly detach, especially on a vehicle that is only 5 years old and has been properly maintained. It is extremely concerning and, in my opinion, negligent for Mercedes-Benz to be aware of this defect and yet fail to extend the recall to all affected. The advisor acknowledged this issue was likely due to a problem with the adhesive used to secure the panel, something he said he had seen happen on other vehicles. Despite this, I was told I would be fully responsible for the repair costs. There were no warnings or signs this would this happen, the panel detached suddenly.
Aug 11, 2025
The rear camera system becomes inoperable when car is first started and put in reverse, then all cameras remain interoperable while driving until sometime later after the car is turned off. This problem occurs intermittently. The symptoms match those described in Mercedes recall campaign 22S20, NHTSA Campaign 22V232. The recall names Mercedes Benz GLC300 but my vehicle’s VIN number does not appear in that campaign. Can it be added?
Oct 21, 2024
Sunroof stopped working, no longer sits flush with vehicle, will not open. I’ve seen recalls for other models/years regarding unsafe sunroof, potential of detaching sunroof. I believe my vehicle should be included in this recall as well.
Oct 31, 2023
The manufacturer service dealer (Mercedes) has been unable to clear a VIN recall notice, even though they say it has been updated. The system still says it's recall. They have had the vehicle for almost 30 days, and have not been able to fix the issue. The recall is for a software update, and the dealer says they've done everything at Mercedes of Ft Lauderdale, and the Manufacturer, (Mercedes) says it's the dealer problem. The dealer says its Mercedes problem, and we as the customer are stuck in the middle and have no car
Jan 09, 2023
+ 5 more complaints for this component
FORWARD COLLISION AVOIDANCE
4 complaints
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.
Sep 23, 2025
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.
Oct 05, 2024
My car has Distronic (radar cruise control), and it worked perfectly until I got my car back after routine maintenance (oil change) at my Mercedes Benz dealership in late summer of this year (2023). Now, the system is behaving dangerously aggressive, for example breaking too late for cars in front which have slowed or stopped in stop-and-go freeway traffic. It is acting like the dealership installed a software update for the wrong car (perhaps a lighter weight or lower powered car.) The system has become so disconcerting I've mostly stopped using it because it feels so unsafe.
Oct 28, 2023
WHILE DRIVING UNDER AN OVERPASS THE BREAKS ACTIVATED ABRUPTLY AND UNEXPECTEDLY. WE WHERE GOING ABOUT 35 MILES PER HOUR AND IF IT WASN'T FOR THE SEAT BELTS WE WOULD OF HIT THE WINDSHIELD. LUCKILY NO ONE WAS FOLLOWING US UP CLOSE.. IT HAPPENED TWICE AT THE SAME SPOT WHERE THERE IS A SHADOW FROM THE OVERPASS (AT SAME TIME OF DAY)
Mar 29, 2021
BACK OVER PREVENTION
4 complaints
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.
Jul 17, 2025
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.
Apr 22, 2025
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that the rearview camera displayed a reverse mirror image. The contact related the failure to NHTSA Campaign Number: 22V232000 (Back Over Prevention). The vehicle was not diagnosed nor repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 60,000.
Mar 20, 2023
In July 2021, Mercedes notified me of NHTSA Recall #21V354 n certain MY 2019-2021 Mercedes-Benz vehicles listed above, under certain conditions, the MBUX multimedia system might not start and the display might remain black, or could reboot unintentionally after 50 seconds of initial startup. Accordingly, the rearview camera image might not be displayed or the display might be interrupted which could reduce the driver’s rear view, and increase the risk of a crash or injury. Mercedes indicated the update would be pushed to the car Over the Air (OTA). More than a year later, the update still has not been pushed OTA. I took the car to the Mercedes dealer that I bought the car from and they were unable to install the update either. It's apparent that Mercedes OTA process does not work for all vehicles, and Mercedes has provided me no method by which I can get the update completed.
Jul 22, 2022
ELECTRICAL SYSTEM,BACK OVER PREVENTION
4 complaints
Center COMAND screen malfunctions. No rear camera view when reversing when screen does not work. Dealer attempted a repair but issue remains. Parts ordered for replacement.
Apr 04, 2024
The contact owns a 2020 Mercedes-Benz GLC300. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
Oct 27, 2022
The contact owns a 2020 Mercedes-Benz AMG GLC43. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated while reversing, the rearview camera failed to operate as needed. There was no warning light illuminated. The manufacturer was notified of the failure but provided no assistance. The vehicle was not repaired. The failure mileage was approximately 30,000. Parts distribution disconnect.
Jun 30, 2022
The contact owns a 2020 Mercedes-Benz GLC300. The contact received notification of NHTSA Campaign Number: 21V354000 (Back Over Prevention, Electrical System). The dealer was notified of the recall and informed the contact that the recall repair would be performed over-the-air (OTA). The contact then called the manufacturer and was informed that the update was not available; he was informed that there was a waiting list and that he would receive a notification when the update for the vehicle was available. The contact had not experienced a failure. Parts distribution disconnect.
Feb 25, 2022
EXTERIOR LIGHTING
3 complaints
Problem (repeat failure / prior warranty replacement): This vehicle has a recurring headlamp defect involving moisture ingress into the headlamp housing/connectors, causing electrical shorting and warning messages, with risk of headlight failure. Mercedes-Benz replaced this same headlamp under warranty in 2021 for the identical issue (moisture/shorting). The defect has recurred on the same vehicle.Recent verification: On Oct 13, 2025, the dealer (Mercedes-Benz of North Palm Beach) observed visible condensation/fogging in the lamp and confirmed it matches the prior failure that was repaired under warranty. Pattern affecting other owners: There are multiple consumer complaints in NHTSA’s database describing condensation, moisture intrusion, shorting, and headlamp malfunctions on GLC vehicles, including the 2020 model year. This indicates the issue is not isolated. Related recalls / known condition: NHTSA Recall 22V261 (GLC) identifies headlamp moisture/connector sealing problems leading to lighting failure. While my VIN is not currently included, the failure mechanism is the same: moisture → short → potential loss of headlight illumination. There are also GLC lighting recalls addressing exterior lighting malfunctions, underscoring that lighting faults on this platform are safety-relevant. Safety risk: Headlamp moisture/shorting can disable exterior lighting, reduce nighttime visibility, and increase crash risk. This is a repeat, safety-related defect previously repaired by Mercedes-Benz that has returned. Requested action: Please investigate this headlamp moisture/shorting defect on the 2020 GLC as a recurring safety problem, consider expanding applicable recall/remedy coverage, and direct the manufacturer to provide a durable fix and appropriate remedy for affected vehicles.
Oct 14, 2025
Entire front right headlight assembly and module failed with no headlight, turn signal, park light etc. There is no visible external damage to the assembly although there is some moisture inside assembly. From internet search, it appears that this is a very common failure. Cost is over $2500 for replacement from local mechanics and over $3300 from Mercedes dealerships with little to no warranty for future failures either.
May 15, 2025
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated while driving at an undisclosed speed during a rainstorm, the contact became aware that there was water inside the headlight assembly. Later, the contact stated that while driving at night, the headlamps were not functioning as needed. The contact stated that after a visual inspection, the driver’s and passenger’s side indicators were not functioning. The headlamp warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the headlight assembly. The vehicle was not repaired. The manufacturer was notified of the failure but provided no assistance. The failure mileage was 65,000.
Jul 02, 2024
POWER TRAIN
3 complaints
Winning noise in rear end. We bought used noticed noise getting loader. Took vehicle to dealer. We were informed the rear Differential was bad and would have to be replaced. Vehicle has 61,198 miles on it. Wife drives car around town and on trips out of town. i was told they would have to get replacement form Germany. around $9,088. Dealership has helped with splitting cost $4,544.00. After checking around seems the Mercedes is having some problems with this part. When i escalated to Customer care at MB it took (4) phone calls from me to finally get a response from them. We affeered you half off and nothing there is nothing more we are going to do. But keep receipt incase a recalled happens?? Case # 03071039 (1-800-367-6372). This part should not be something that goes bad on a 2020 with 61,981 miles. Any help would be appreciated!!
Nov 09, 2023
The contact owns a 2020 Mercedes-Benz GLC63. The contact stated that while his wife was driving at highway speeds, the vehicle inadvertently decelerated while the accelerator pedal was being depressed. The check engine warning light illuminated, and a message displayed on the instrument panel stated that the “Transmission Needs to Cool, Stop and Pull Over Immediately”. The contact stated that the vehicle had locked in first gear and decelerated to approximately 55 MPH. Additionally, the contact stated that his wife was able to navigate the vehicle back to the residence. The contact stated that the following day the contact was able to restart the vehicle. The vehicle was taken to the dealer where it remained awaiting a diagnostic test. The vehicle had not yet been repaired. The manufacturer was notified of the failure and the contact was provided a case number. The failure mileage was approximately 24,000.
Oct 13, 2023
It took a few minutes to be able to completely turn left out of a shopping center while waiting in line. When finally able to turn left, the car stalled into what appeared to be neutral where I had no control to increase speed and was turning very slowly. Oncoming traffic from both ways were coming and luckily stopped on-time. I had to turn off the entire car and restart in the middle of the road in order to be able to drive again. There could've been a massive collision if cars were not paying attention on both sides. Note that the car was NOT in neutral at the time and was in drive the entire time. This same incident also happened over a year ago but thought it was something I could've done wrong or was a one-time thing. Now that it's happened twice confirms that there is something wrong with the car. The car did not indicate a power failure or warning lights during this incident. I have an appointment with Mercedes on 4/25 to get this looked at. This has been reported on other models from other car owners but we have never seen a recall. This is a serious malfunction and could've gotten myself or others killed. I do not feel safe driving this car unless it is fixed.
Apr 24, 2022
ELECTRICAL SYSTEM,ENGINE
3 complaints
This is in reference to a 2020 Mercedes GLC350e Plug-In Hybrid. Sole owner purchased January 2020 with under 4 Thousand miles on the odometer, 3 years extended warranty. Took car only to MB Henderson dealership for service/maintenance performance on the vehicle and nowhere else. Dealership has records. The GLC350e received no recall of any kind. On November 11, 2021, the car coolant alert displayed and instructed to shut engine down, key off of ignition and stop everything -- car was not safe to drive. In contacting MB Henderson, NV dealership, they concurred with the display and asked that the vehicle be towed to their facility for further inspection -- No MB Dealership had the capacity to tow the vehicle to their service facilities. So I called using my own AAA Towing and the dealership received the 2020 GLC350e at their facility. They had it overnight and the next day. After checking everything found they can't reproduce the Coolant warning alert display and said the car was safe to drive. Fast forward to March 8th, 2020 this display resurfaced while driving on Interstate 15 southbound to Los Angeles. Called dealership, and their recommendation was again repeated -- Shut off engine, tow it to the nearest dealership. The locatioin was between Bakers and Barstow, and the nearest MB dealership was in Riverside, CA. This is a desolated area and unsafe to stay or leave the car where it is. With what I learned from the November 12, 2021 service performed by the dealership, they couldn't find anything wrong with the car. I felt it important to get off the freeway and proceed to Barstow and call the Riverside Dealership when I get there. This I did and before reaching Barstow, the car engine started to smoke and the hood bulged up. In seconds the bulge was increasing in size, a sliver of flame appeared. This scared me, so I got out of the car in a hurry, and dialed 911 and the insurance company. The flame got more intense and it was totaled.
Jun 16, 2022
The contact's wife owns a 2020 Mercedes-Benz GLC300. The contact stated that while his wife was driving at an undisclosed speed, the vehicle stalled. The vehicle was towed to the dealer and diagnosed with ignition failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure but declined to buy back the vehicle and offered a two-year service plan for a free oil change per year. The failure mileage was approximately 30,000.
Mar 04, 2022
At around 11pm on Monday, Sept 20, 2021 I was driving approximately 65 mph on the highway when the vehicle began to abruptly decelerate for no apparent reason, even when I was pushing on the accelerator pedal. When I would push on the accelerator I could hear the engine revving, I confirmed the car was in the Drive gear but the vehicle began to lose speed rapidly and no matter what action I took the car was only slowing down and had to quickly find an emergency area to pull over. My vehicle is available for inspection. This incident was a very scary situation that put my life and others at risk. I was on a two lane highway in a construction zone and there was no shoulder available to pull off safely. There were tractor trailers that had to swerve to avoid rear ending me in the roadway and I was afraid I was going to be involved in a major accident. In the end I was able to pull into a break in the Jersey barrier to get out of the lane of travel. I have a young baby and do not want to take my child in this car now for fear of it happening again. I had noticed a hesitation in the vehicle before but this is the first time this issue has happened where the car would not accelerate. I am taking the car into the dealer to see if there are any diagnostic codes and it has not been inspected by anyone. Additionally there were no warning lights, no tones, no check engine lights or anything to warn of the situation before or while it was happening. From the inside of the vehicle the car appeared to be normal but it was not clearly given the lose of power and rapid deceleration.
Sep 21, 2021
STRUCTURE
2 complaints
Panoramic sunroof blew off vehicle while driving. Other drivers were put at a risk from a vehicle component flying through the air at high speed. The vehicle has been inspected by the dealership. No warnings prior to the problem. There is a recall with Mercedes Benz for this issue buy my VIN is not the included number but should be included.
Jun 16, 2025
THE SUNROOF OF OUR CAR SHATTERED BY ITSELF WHEN WE WERE DRIVING ON A CITY STREET. THERE WAS NO PROJECTILE THAT CAUSED THE SUNROOF TO SHATTER AND THE DEALERSHIP WAS ABLE TO CONFIRM THAT. BUT THE DEALERSHIP AND THE COMPANY ARE UNABLE TO SAY FOR CERTAIN WHY THIS HAPPENED AND WHETHER OR NOT THIS WILL HAPPEN AGAIN. THE INCIDENT CAUSED GLASS TO FALL ON ALL OUR PASSENGERS AND THE SOUND OF THE GLASS SHATTERING DURING DRIVING REALLY SCARED US. WE ARE CONCERNED FOR OUR SAFETY AND EVEN MORE CONCERNED THAT MERCEDES IS UNABLE TO DIAGNOSE WHY THIS HAPPENED AND ARE NOT ABLE TO SAY FOR SURE THAT IT WOULD NOT HAPPEN AGAIN.
Apr 29, 2021
AIR BAGS
2 complaints
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that while operating the vehicle, the air bag warning light remained illuminated, indicating that the front passenger’s side seat air bag was inoperable. The cause of the failure was not yet determined. The local dealer and manufacturer were notified of the failure, but no assistance was offered. The failure mileage was approximately 30,000.
Nov 07, 2024
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that upon driving through an intersection at 40 mph, another vehicle had run a stoplight. The contact swerved in an attempted to avoid the vehicle, however, she had hit the vehicle's rear driver side tire weld. The contact stated that the driver-side airbag did not deploy upon impact; however, the passenger-side airbag, where her mother was seated, did deploy. The Mercedes-Me app automatically called 911 and the contact initially declined medical attention at the time. A police report was filed. Due to the failure, the vehicle was towed to an independent mechanic. The next day, the contact was referred by her doctor to a hospital where they performed a cat scan and x-ray. The contact tested positive for Covid-19 the following Monday and believed it was as a result of the hospital visit. The manufacturer was notified of the failure and upon her own research, the contact discovered NHTSA Campaign Number: 21V354000(BACK OVER PREVENTION, ELECTRICAL SYSTEM). The vehicle remained in the possession of the independent mechanic and had yet to be repaired. The failure mileage was unknown.
May 28, 2021
STEERING
2 complaints
the power steering wheel adjustment stopped working, leaving the steering wheel stuck in a very unconfutable position for driving. The car just ended its 4 yr warranty
Apr 17, 2024
THE VEHICLE WONDERS WITHIN THE LANE WHEN MERCEDES DISTRONIC DRIVER ASSISTANCE IS ACTIVATED, PARTICULARLY ON GENTLE CURVES AT HIGHWAY SPEEDS. IT WILL HIT LANE BUMPS UNLESS THE DRIVER ACTIVELY STEERS AWAY FROM THE LANE MARKINGS. THE 2020 GLC3004MATIC HAS BEEN DOING THIS SINCE WE PURCHASED IT NEW ON JANUARY 2, 2020. MERCEDES DEALER HAS CHECKED THE VEHICLE AND IS NOW DESCRIBING THE VEHICLES BEHAVIOR AS NORMAL. ACCORDING TO MERCEDES THIS IS A NEW DRIVER ASSISTANCE PACKAGE IN THE 2020 GLC. IT IS A MAJOR SAFETY HAZARD IF THE VEHICLE IS NOT ACTIVELY CONTROLLED BY THE DRIVER AT ALL TIMES. THIS IS NOT AN ASSISTANCE PACKAGE AS DESCRIBED BY MERCEDES. WE HAVE DRIVEN OLDER MERCEDES WITH THE DISTRONIC SYSTEM THAT STAYED IN THE LANE VS. THE WONDERING. WE DO NOT TAKE OUR HANDS OFF THE STEERING WHEEL THE VEHICLE DOES THIS ON IT'S OWN PRIOR TO ANY WARNINGS RELATED TO DRIVER AWARENESS OR ACTIONS. THIS ACTION BY THE VEHICLE WHEN DISTRONIC IS ACTIVATED WILL CAUSE SERIOUS LIFE THREATENING ACCIDENTS.
Feb 26, 2020
ELECTRICAL SYSTEM
2 complaints
The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that while operating the vehicle, the 12-Volt battery warning light remained illuminated. The contact stated that while driving at various speeds, the vehicle shut off. The failure also occurred while driving on a busy freeway. The vehicle was towed to the local dealer who diagnosed that the STOP/START button was faulty and needed to be replaced. The STOP/START button was replaced but the failure persisted. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was 40,000.
Dec 05, 2023
WHEN USING ENGINE START/STOP FUNCTION, OVER THE COURSE OF 3 DAYS AFTER PICKING UP THE CAR, WHEN AT A LIGHT, THE CAR DID NOT START BACK UP.
Nov 04, 2020
ENGINE,FUEL/PROPULSION SYSTEM
1 complaint
Nationwide known cylinder head issues. Cylinder head work needing replaced.
Oct 30, 2025
VEHICLE SPEED CONTROL,ENGINE
1 complaint
The engine is failing, I was on my way to drop my [XXX] off at daycare when suddenly my car went above and stayed above 5rpms meanwhile I was only able to drive 8mph. This caused a tractor trailer swerving into on coming traffic, if he didn’t my toddler and I would have been killed. As I managed to pull off and call my husband to get the baby the engine started making a strange clicking noise. There’s maybe 60,000 miles on this vehicle none of this should be happening. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Oct 10, 2025
UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM
1 complaint
Dear Sirs: I own a 2020 GLC300W Mercedes SUV. As of this date, It has stalled 5 times while driving on the highway and on the roads within an 8 month period. Throughout this period, I have taken the vehicle to the Mercedes dealership in Riverside, CA three times to have this inspected. After their first inspection, the dealership claimed that the problem was due to a recall on a computer software update needed. However, the vehicle stalled two more times while driving on the highway. After the second inspection, the dealership claimed the problem was due to a bad throttle actuator and charged me $2000 for the repair. Two months later, the vehicle stalled on the road once again. Currently, the dealership is inspecting the vehicle for a THIRD time. I have viewed your NHTS website and came across NHTSA campaign number: 23V445, Problem Description: Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2021-2023 C-Class, E-Class, S-Class, CLS, SL, GT, GLC, GLE, GLS, and G-Class vehicles. Please refer to MBUSA's recall report for specific vehicle details. The fuel pump may shutdown, which can result in a loss of drive power." I believe this is the cause of my 2020 Mercedes doing the exact same thing, however the 2020 model is not listed in this recall. Please investigate this as this may be fuel pump issue applies to 2020 models.
Mar 27, 2025
STRUCTURE,UNKNOWN OR OTHER,VISIBILITY/WIPER
1 complaint
On Saturday October 5th at roughly 8:30 p.m. heading West on I-94 near battle creek, MI, the glass sunroof on our Mercedes suddenly exploded out and shattered. We were traveling at 75 mph with little surrounding traffic and no over-head obstructions. It took a second to re-gain control of the situation and slow down to a stop. We had the sun-shade closed, saving us from glass shards raining down from the exploded sunroof. The following Monday morning, Oct 7th around 9:00 a.m., we called Mercedes about the issue. They were indifferent and offered no assistance. They pointed out that our MY2020 with 29,711 miles on the odo was not covered under warranty for the sunroof shattering and that we would have to deal with our insurance company. They also informed us that they would not have any rental cars available during a repair until at least December. We mentioned that there was signs on the internet of class-actions against Mercedes for similar sunglass explosions to which they quickly responded with - not on MY20 300 GLC. We did get the sunroof replaced through our insurance. Anecdotely, when we took it into the glass repair shop, they had just did another one, similar situation the week before. This could have been tragic. Glass shards could have been everywhere. The only reason the sunscreen was deployed was that we had our baby granddaughter in the car only 1 hour earlier. Otherwise, that screen would have been open and the glass would have rained down on everyone in the car.
Oct 14, 2024
STEERING,TIRES
1 complaint
The contact owns a 2020 Mercedes-Benz GLC300 equipped with Goodyear Tires, Tire Line: Eagle Sport All Season, Tire Size: 255/45/R20, DOT Number: NE12JU1R1021. The contact stated that within a year of purchasing the vehicle brand new, he noticed that there was significant amount of rubber coming off the outer side of the front passenger's side tire. The contact stated that the failure was moderate on the front driver's side tire. The contact stated that the vehicle was taken to the dealer, where the front driver's side tire was replaced twice due to the failure. Additionally, the front passenger's side tire was replaced three times; however, the failure persisted. The contact stated that upon investigating the failure online, he learned that the steering knuckle might be damaging the tires. The dealer was notified of the failure. The vehicle was not diagnosed or repaired. The vehicle and the tire failure mileage were approximately 6,000.
Aug 14, 2024
UNKNOWN OR OTHER,SERVICE BRAKES
1 complaint
I have had issues with squeaky, very loud noises at slow speed and reverse braking. I have had this issue since I purchased this vehicle. I have brought it in a few times to have 2 different dealers fix the noise as I believe it is a safety issue as well. They said this is a common issue with GLC that they have noises while braking but there is no fix. I had an advisor drive the vehicle and witness loud squeaky noises while braking. Spending a lot of money on this vehicle, and Mercedes should fix this issue. I believe the brake system falls under lemon law and Mercedes should do something to mitigate the issue. The brake pads were okay upon inspection, but pretty soon I will have to pay a lot of money to replace pads at my own expense when the brakes, pads, rotors, etc themselves should be replaced and fixed at Mercedes expense.
Dec 29, 2023
UNKNOWN OR OTHER,SERVICE BRAKES,ENGINE
1 complaint
2020 AMG GLC 43 coupe here in Harrison, NJ. My driving style with this vehicle isn't different in any relevant way versus with past vehicles. There is an acceleration dead spot which is the default occurrence when I am coasting at a low speed and then go to accelerate. Common scenarios are driving toward an intersection and rolling forward as you determine if you are clear to go and then accelerating, or slowing down to let a car in the lane next to you go by so you can then switch lanes and accelerate. I swear, I've almost gotten killed a few times when I had time to go but only if I hustled; depress the accelerator, and nothing happens for a full second. Then I go from having enough time to almost getting hit.
Dec 14, 2023
STEERING,SEATS,SERVICE BRAKES
1 complaint
The first day the car was picked up by us, we turned back and complained about the steering wheel and drivers' seat vibration. They checked it and we were told they cannot find anything. We were told to drive the car for awhile and return it if this complaint persists. We returned it to Okemos Mercedes with the same complaint. They said it is the tires and they replaced the right front tire. I told them I was driving since I was 17 and I know the difference between body and tire problems. We were told to try it again and come back and if it persists to return for diagnostics. Same response. I have complained to both dealership and and Mercedes main office and Mercedes does not agree it is a warranty issue. During the July 4th holidays, our son drove it and it was the first time I became a passenger. I cannot believe how scary the vibrations, noise and feeling unsafe in the back was. I made numerous calls to Mercedes and they keep pointing at the tires as the issue. The tires are supposed to have 2 more years tread left but Mercedes Okemos tried to sell us a tire. I was told by Mercedes main office to keep calling [XXX] at Okemos Mercedes service center but he had not returned calls. Mercedes main office said [XXX] had not returned calls, either. They were pointing fingers at each other while we were driving our grandchildren in an unsafe car. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Jul 25, 2023
STEERING,SUSPENSION,UNKNOWN OR OTHER
1 complaint
There is a squeaky noise from the suspension, shock absorbers or somewhere in that area. They have fixed the issue multiple times. Kept my car in the workshop for days multiple times but it’s not getting fixed. They probably sold me a lemon. I need help in rectifying this issue.
Apr 09, 2023
FUEL/PROPULSION SYSTEM
1 complaint
Driving slowly through a parking lot and had to stop for pedestrians. When the path was clear, the car would not accelerate. It only idled forward and slowly reached about 5 mph. Stepping on the accelerator pedal gave no response after repeatedly trying to accelerate. No warning lights came on to alert me of a problem. I was able to pull into a parking spot and after shutting off the ignition and turning back on, the throttle responded as normal. This was a very scary situation but at least it happened in a parking lot.
Oct 01, 2022
VEHICLE SPEED CONTROL
1 complaint
The contact owns a 2020 Mercedes-Benz GLC43. The contact stated that while driving at an undisclosed speed, the vehicle hesitated to accelerate after coming to a complete stop while the steering wheel was turned. The vehicle was taken to the dealer where it was diagnosed that the electronic throttle control (ETC) software needed to be replaced; however, the dealer was unable to replace the ETC software and referred the contact to the manufacturer for further assistance. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The manufacturer declined the contact's request to buy back the vehicle. The failure mileage was approximately 800. The consumer requested Mercedes Benz buy the vehicle back, but they only offered a free months payment and release of liability but consumer refused the offer.
Aug 11, 2022
ELECTRICAL SYSTEM,STRUCTURE,ENGINE
1 complaint
Engine coolant after 2000 miles from topped off by dealership got low and sparked fire, and totaled my car. Warning alert was ON to say turn off engine remove key. Articles related to this: 800,000 Mercedes-Benz Owners Warned Their Cars Could Catch Fire (forbes.com) Daimler warns car owners of fire risk it lacks parts to fix | Reuters 800,000 Mercedes Vehicles Are In Risk Of Catching Fire, But They Don't Have The Parts To Fix It (topspeed.com) Auto manufacturer Daimler advised 800,000 Mercedes-Benz owners that a technical defect could cause their cars to catch fire, but said it lacked the parts to fix the defect immediately, warning owners to instead drive “particularly carefully.” When confronted with the above with Mercedes Benz my vehicle fire MB maintained that the fire is a hot surface ignition issue and denied the car had any design issue. In the article, MB's warning to owners to instead drive "particularly carefully" means to me that they do admit there are critical and chronic issues with the car that would not only produce trip interruptions but catch fire altogether. It is mandatory for Mercedes to redesign the coolant's chronic issues and make the recall so that more owners will not be faced with the problem I had -- total loss of the vehicle.
Jul 24, 2022
LANE DEPARTURE,FORWARD COLLISION AVOIDANCE
1 complaint
Self driving assist, adaptive cruise , emergency braking assist do not work. Taken to dealer three times , unable to correct. Returned to customer with out paperwork documenting repair of safety systems. Problems are still in I repaired state. Emergency braking system warning message has activated 15-20 times after receiving car back. Other existing problems are still on going as well. Requested District service Manager consult the situation and advise. Love car , want to have repaired . Looking to add additional GLC to household . Hope repair is possible . ????! Hate to have accident, bad for health. Please contact. [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
May 20, 2022
WHEELS
1 complaint
The contact owns a 2020 Mercedes Benz GLC300. The contact stated that while driving at approximately 60 MPH, the front of the vehicle was vibrating and shaking violently. The vehicle was taken to the dealer where they informed the contact that the tires were balanced and needed to be rotated. The vehicle was repaired however, a month later the failure persisted. The vehicle was taken back to the dealer where it was diagnosed that the rear tires needed to be replaced. The vehicle was repaired but a few months later the failure recurred. The vehicle was taken back to the dealer where it was diagnosed that the front tires were worn unevenly and a four-wheel alignment was needed. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 450.
Jan 13, 2022
VEHICLE SPEED CONTROL,UNKNOWN OR OTHER
1 complaint
I WAS DRIVING AND STOPPED CAR TO MAKE A TURN WAITING FOR INCOMING TRAFFIC TO CLEAR. WHEN I WENT TO ACCELERATE AFTER TRAFFIC CLEARED, THE CAR WOULD NOT GO ABOVE 0.5 MILES PER HOUR. I MADE SURE THE GEAR HAD NOT SHIFTED TO NEUTRAL, IT WAS ON COMFORT DRIVE. I CHANGED TO SPORTS DRIVE AND THE CAR STILL WOULD NOT ACCELERATE ABOVE 0.5 MILES. I WAS NOW STUCK IN THE MIDDLE OF INTERSECTION WITH INCOMING TRAFFIC, SO I TRIED TO REVERSE. THE CAR REVERSED NO FASTER THAN 0.5 MILES PER HOUR. I TURNED CAR OFF AND BACK ON, AND ACCELERATION THEN WORKED. VERY SCARY. I WAS LUCKY INCOMING TRAFFIC AVOIDED ME. BIG SAFETY HAZARD. DEALERSHIP SO FAR HAS NOT BEEN ABLE TO REPLICATE THE ISSUE, BUT I READ OTHER BLOGS WHERE PEOPLE EXPERIENCED A SIMILAR EVENT.
Apr 26, 2021
POWER TRAIN,ENGINE
1 complaint
THIS VEHICLE IS UNSAFE. WHEN DRIVING IN TRAFFIC THE ENGINE/TRANSMISSION WILL NOT DELIVER POWER IN RESPONSE TO THROTTLE APPLICATION, IT IS ALSO INCONSISTENT IN IT'S RESPONSE FROM ONE TIME TO THE NEXT. THE VEHICLE WILL HESITATE FOR UP TO 4-5 SECONDS BEFORE RESPONDING TO THROTTLE COMMANDS WHEN PULLING OUT INTO TRAFFIC. THIS IS MOST NOTICEABLE WHILE ROLLING BETWEEN 5-10 MPH AND APPLYING POWER ALSO WHILE MAKING A SHARP TURN. THE POWERTRAIN ALSO IS EXTREMELY INCONSISTENT IN IT'S RESPONSE WHICH MAKES PULLING INTO TRAFFIC EXTREMELY DANGEROUS. I SUSPECT THE PROBLEM STEMS FROM SENSORS IN THE ELECTRONIC STABILITY PROGRAM (MB ESP), THE TRANSMISSION MODULE AND THE FLY BY WIRE THROTTLE AND ENGINE CONTROL MODULE. PROGRAMING OF SHIFTS OF THE TRANSMISSION SEEM TO FIGHTING WITHIN THE TRANSMISSION ITSELF. ALL OF THIS ADDS UP TO AN EXTREMELY DANGEROUS SITUATION WHEN DRIVING IN TRAFFIC. I HAVE TAKEN THE VEHICLE BACK TO THE SELLING DEALER (MERCEDES BENZ OF NORTH PALM BEACH FLORIDA) TWICE ONLY TO BE TOLD THAT THIS IS NORMAL. I FILED A REQUEST WITH MERCEDES BENZ OF NORTH AMERICA TO BUY THE CAR BACK WITHOUT SUCCESS.
Dec 09, 2020
SERVICE BRAKES
1 complaint
DRIVING ALONG RANDOM TRAFFIC NO PATTERN, AUTOMATIC BRAKE ASSIST IS TEMPORARILY NOT ACTIVE , BRIGHT YELLOW WORDING, DANGER AUTO BRAKE ASSIST WILL NOT FUNCTION AT THIS TIME.
Jan 15, 2020
Frequently Asked Questions
How many problems does the 2020 MERCEDES-BENZ GLC-Class have?
The 2020 MERCEDES-BENZ GLC-Class currently has 71 owner-reported complaints according to NHTSA database. These complaints are organized by component to help identify common issues.
What are the most common problems with 2020 MERCEDES-BENZ GLC-Class?
The most common problems reported for the 2020 MERCEDES-BENZ GLC-Class are organized by component above. Each component section shows owner-reported issues, crash reports, and fire incidents to help identify patterns and problem areas.
Where does this 2020 MERCEDES-BENZ GLC-Class problem data come from?
All problem and complaint data for the 2020 MERCEDES-BENZ GLC-Class comes directly from the National Highway Traffic Safety Administration (NHTSA) database. These are real complaints submitted by actual vehicle owners.
Other Years - MERCEDES-BENZ GLC-Class Problems
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