2022 Mercedes-Benz GLC 300 Problems

My 2022 Mercedes-Benz GLC 300 (17,700 total miles) suffered a catastrophic structural engine block failure and an explosive loss of propulsion while driving at highway speeds. This occurred exactly 6 days and 183 miles after a franchised Mercedes-Benz dealership performed the official fuel pump impeller safety recall (NHTSA Campaign 23V-445).The dealership's official repair invoice documents that the technician custom-modified the recall remedy by reusing parts, explicitly stating: 'Relocated floater from old pump onto new fuel pump.' Simultaneously with the mechanical engine failure, a 'Reduce Engine Oil Level' message flashed on the dashboard, indicating severe fuel dilution from the compromised fuel system.The dealership is actively violating federal recall mandates by refusing to investigate this failed safety remedy unless I sign an open-ended financial check for a diagnostic and teardown fee. They have also revoked my substitute transportation to coerce payment. Mercedes-Benz USA Corporate Case Number 23652724 has been opened. I am requesting a federal safety investigation into this dealer's non-compliant recall remedy execution."

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.

Loss of Steering Control at Highway Speeds – 2022 Mercedes-Benz GLC300 Vehicle: 2022 Mercedes-Benz GLC300, VIN [XXX] Dates of Incident: September 13th and October 4th Mileage at Time of Incident: 39,500 While driving on a four-lane expressway at highway speeds, my vehicle suddenly and completely lost steering control, resulting in a total inability to steer. First Incident The first event occurred during light rain with mildly wet road conditions. Without warning, the vehicle hydroplaned and violently crossed all four lanes approximately 20–25 times, narrowly avoiding collisions with other vehicles and medians. The steering wheel was completely unresponsive. After several minutes, the car inexplicably corrected its course. Second Incident The second incident occurred weeks later under clear, dry conditions with my minor child in the car. Once again, the steering wheel locked, leaving me unable to direct the vehicle. I had to physically force the wheel to prevent the car from leaving the highway. Investigation The car was towed to Mercedes-Benz of Coral Gables, where technicians were unable to find any fault despite multiple diagnostic attempts. I have since discovered that 2023 and 2024 models of this same vehicle are under active recall for a similar steering malfunction, which may indicate that 2022 models are also affected. Safety Concern This defect poses an imminent risk of fatal accidents, both to occupants and to other drivers. The failure occurs without warning, at high speeds, and results in total loss of steering control. Requested Action I request that the NHTSA investigate whether 2022 models should be included in the existing recall related to steering control failure in Mercedes-Benz vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I was driving home on a 4 Lane Expressway on a Saturday afternoon, it was mildly raining with the roads a little wet. I suddenly lost control of the car and could not control the steering wheel, the car ended up hydroplaning and I lost control it ping-ponged across four expressway lanes back-and-forth about 20 to 25 times with zero control of the steering wheel, barely missing the medians and other cars. It should have been a massive catastrophe. Cars around me you had to stop and swerve around me to avoid hitting me all while driving on the expressway. Had someone accidentally hit me in the process it would’ve certainly flipped the car and I would’ve either ended up dead or in the ICU. After several minutes somehow without moving the steering wheel, I managed to just go straight and pull over. And waited for help to get back safely slowly. I thought the incident was isolated because the roads might have been the cause. But I went out out of the country and upon coming back, drove my car again on the expressway coming back home and the exact same thing happened with my minor child in the car across two expressway lanes in the evening time With the roads perfectly dry. Lost control of the steering wheel could not steer or direct the car and had to jerk it from to prevent it from driving off the highway. It seemed to have occurred both times at a higher velocity on expressways when the steering wheel needed to be engaged. I had it towed to the Mercedes Benz Of Coral Gables dealership, but they cannot find anything wrong with the car, even though the exact same model of my car has an active recall for 2023 and 2024 models. For the same problem, I later learned. Mine is a 2022. I have been in a loaner vehicle for three weeks while they investigate and I need Assistance to make sure that something gets done because nothing has been found and I do not want to risk driving with my child in the car.

While driving down a busy neighborhood street 2 lanes with cars on both sides making it a 1 lane road pulled over to the side a little to let cars pass. All of a sudden ALL electrical and engine stopped and turned off. Only thing that was powered was instrument cluster with multiple warnings like SRS Malfunction, Steering Malfunction, SOS Inoperative, Parking Brake and more. We believe the car had also shifted to park on its own. No power to anything not even hazard lights. Nothing electrical had any sort of power. Could not even turn car off completely could not get the instrument cluster to turn off with ignition button. When I say everything electrical had no power I mean everything except instrument cluster. Hazard lights power locks, lights of any kind, ignition switch, gear selector, windows, sos feature, nothing had power. I could not imagine having this issue driving on the interstate and having the car completely loose ALL electrical power and what could happen to specially with a SRS malfunction and issue with steering. Had to have a wrecker come with wheel dollys because car could not be put in neutral and towed to Mercedes dealer. Upon their inspection they found the Circuit 30T relay to be stuck in the open position which killed power to everything so the technician replaced the engine compartment pre-fuse panel. It is such a unsafe and very hazardous issue to have a relay failure to where all power is lost especially if you were driving on interstate especially at night with traffic to loose everything electrical even hazard lights and headlights, SRS maltunction, Steering. Mercedes needs to figure this very unsafe issue out.

My vehicle got stuck on a EPB(electronic parking brake) and I was unable to disengage it. I tried a few things and none worked. I contacted Mercedes to tow it to the dealer and the tow truck came and driver had to “drag” my vehicle on to the flatbed. My car has been at Mercedes for 5 days now and they gave me a response saying that they are having a hard time trying to disengage the EPB. I’m aware of a EPB recall but my model is specified as being a part of it, however the issue is closely related to the recall so please take further interest in my situation because it could be the start of a new recall. The dealer says they have tried and failed to disengage it. My car was working just fine so please take further look at a possible software glitch for the EPB.

My 2022 Mercedes-Benz GLC 300 (17,700 total miles) suffered a catastrophic structural engine block failure and an explosive loss of propulsion while driving at highway speeds. This occurred exactly 6 days and 183 miles after a franchised Mercedes-Benz dealership performed the official fuel pump impeller safety recall (NHTSA Campaign 23V-445).The dealership's official repair invoice documents that the technician custom-modified the recall remedy by reusing parts, explicitly stating: 'Relocated floater from old pump onto new fuel pump.' Simultaneously with the mechanical engine failure, a 'Reduce Engine Oil Level' message flashed on the dashboard, indicating severe fuel dilution from the compromised fuel system.The dealership is actively violating federal recall mandates by refusing to investigate this failed safety remedy unless I sign an open-ended financial check for a diagnostic and teardown fee. They have also revoked my substitute transportation to coerce payment. Mercedes-Benz USA Corporate Case Number 23652724 has been opened. I am requesting a federal safety investigation into this dealer's non-compliant recall remedy execution."

While driving down a busy neighborhood street 2 lanes with cars on both sides making it a 1 lane road pulled over to the side a little to let cars pass. All of a sudden ALL electrical and engine stopped and turned off. Only thing that was powered was instrument cluster with multiple warnings like SRS Malfunction, Steering Malfunction, SOS Inoperative, Parking Brake and more. We believe the car had also shifted to park on its own. No power to anything not even hazard lights. Nothing electrical had any sort of power. Could not even turn car off completely could not get the instrument cluster to turn off with ignition button. When I say everything electrical had no power I mean everything except instrument cluster. Hazard lights power locks, lights of any kind, ignition switch, gear selector, windows, sos feature, nothing had power. I could not imagine having this issue driving on the interstate and having the car completely loose ALL electrical power and what could happen to specially with a SRS malfunction and issue with steering. Had to have a wrecker come with wheel dollys because car could not be put in neutral and towed to Mercedes dealer. Upon their inspection they found the Circuit 30T relay to be stuck in the open position which killed power to everything so the technician replaced the engine compartment pre-fuse panel. It is such a unsafe and very hazardous issue to have a relay failure to where all power is lost especially if you were driving on interstate especially at night with traffic to loose everything electrical even hazard lights and headlights, SRS maltunction, Steering. Mercedes needs to figure this very unsafe issue out.

I have experienced 4 incidents of the car accelerating on its own. I have taken it to the dealership twice and they are unable to reproduce the problem. Problems began occurring in 2025 and occurred again this past week (August 20246). In the most recent incident I was accelerating on an "on ramp". The car suddenly took hold and continued to speed up despite my foot not being on the gas. I had to drive the car to safety with my foot on the break. The moment I took my foot off the break it would speed up. The floor mat was not touching the gas in all of the instances of this occurring. The gas pedal was not stuck to anything. I nearly avoided a serious accident as where i was trying to merge was running out of a lane and a cement block was in front of me. I was also with an infant and 2 year old in my car. There have been no warning messages when this occurs.

I was involved in a severe front-end collision where my vehicle struck another vehicle with significant force. Despite the major impact, the front airbags did NOT deploy. The entire front end of the vehicle was crushed, including destruction of the radiator, damage to engine components, internal structural collapse, and leaking fluids. Based on the severity and direct frontal nature of the crash, airbags should have deployed but did not. As a result of the impact, I sustained a neck and upper shoulder injury and required medical evaluation. There were no warning lights or messages prior to the crash indicating any malfunction in the airbag or SRS system. The vehicle is available for inspection by NHTSA, the manufacturer, insurance, or an authorized Mercedes-Benz service center. This appears to be a possible failure of the airbag/SRS system during a qualifying collision.

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving 60 MPH, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that there were several unknown warning lights illuminated before the engine seized. The vehicle was restarted; however, while driving at an undisclosed speed, the failure reoccurred. The contact started the vehicle again, and the vehicle was slowly driven to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 51,519.

Defect Summary: Since 2024, my 2022 Mercedes-Benz GLC300 has had a persistent, abnormal engine noise consistent with the sound of a 4-cylinder diesel engine, despite being gasoline-powered. The noise occurs both while idling and in motion. On several occasions, the coolant warning light illuminated while the noise persisted. The defect has worsened over time, becoming louder and more frequent. Events & Safety Risks: The dealership repeatedly claimed “no problem found” because no warning lights appeared and no scanner codes were present, ignoring my time-stamped video evidence. At one point, I was advised to drive the vehicle from Morgan Hill, CA to the dealership while making the loud noise for diagnostics — an unsafe recommendation. When the coolant warning light appeared, the service department planned only to top off coolant. I insisted on a diagnostic, which revealed a coolant hose leak. Driving with a leak could cause overheating and sudden engine failure, creating a serious safety hazard for myself, my child, and other motorists. Repair History: Multiple visits to Mercedes-Benz of San Jose (2024–2025) for the same defect. Each time, the defect was dismissed or not resolved. No meaningful repairs were performed. The issue persists today. Evidence: Time-stamped video proof of defect, full service records, and documentation of correspondence with the dealership are available. Safety Concern: This unresolved defect creates a risk of sudden engine failure or overheating while driving, potentially causing loss of control or stranding occupants in unsafe conditions.

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving at 65 MPH, the sunroof exploded. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 56,000.

Since I purchased this vehicle 2.5 months ago, the windshield wipers started chattering/making noise and not working properly after about 2 days. I brought the car in and the dealership replaced the wipers. The chattering started again shortly after, then the dealership polished the windshield. It worked well for about 2-3 weeks and now the wipers are starting to streak and chatter again. I have a third appointment to have the windshield re-polished and wipers replaced, again. I have no faith this will fix the issue since its been done before. I see that this is a common issue with this brand/model.

While driving down a busy neighborhood street 2 lanes with cars on both sides making it a 1 lane road pulled over to the side a little to let cars pass. All of a sudden ALL electrical and engine stopped and turned off. Only thing that was powered was instrument cluster with multiple warnings like SRS Malfunction, Steering Malfunction, SOS Inoperative, Parking Brake and more. We believe the car had also shifted to park on its own. No power to anything not even hazard lights. Nothing electrical had any sort of power. Could not even turn car off completely could not get the instrument cluster to turn off with ignition button. When I say everything electrical had no power I mean everything except instrument cluster. Hazard lights power locks, lights of any kind, ignition switch, gear selector, windows, sos feature, nothing had power. I could not imagine having this issue driving on the interstate and having the car completely loose ALL electrical power and what could happen to specially with a SRS malfunction and issue with steering. Had to have a wrecker come with wheel dollys because car could not be put in neutral and towed to Mercedes dealer. Upon their inspection they found the Circuit 30T relay to be stuck in the open position which killed power to everything so the technician replaced the engine compartment pre-fuse panel. It is such a unsafe and very hazardous issue to have a relay failure to where all power is lost especially if you were driving on interstate especially at night with traffic to loose everything electrical even hazard lights and headlights, SRS maltunction, Steering. Mercedes needs to figure this very unsafe issue out.

My vehicle got stuck on a EPB(electronic parking brake) and I was unable to disengage it. I tried a few things and none worked. I contacted Mercedes to tow it to the dealer and the tow truck came and driver had to “drag” my vehicle on to the flatbed. My car has been at Mercedes for 5 days now and they gave me a response saying that they are having a hard time trying to disengage the EPB. I’m aware of a EPB recall but my model is specified as being a part of it, however the issue is closely related to the recall so please take further interest in my situation because it could be the start of a new recall. The dealer says they have tried and failed to disengage it. My car was working just fine so please take further look at a possible software glitch for the EPB.

Vehicle vibrates quite violently when hit some potholes. Steering wheel is the part that vibrates more but vibration is felt throughout the vehicle. It is more prevalent at highway between 55-65 mph speed. I also noticed that car shakes unusually and tilts to one side at times making it quite uncomfortable for driver. back tires make slipping noice on potholes and feels like car is going to be unstable momentarily . All these issues are putting driver and others at risk. I joined Facebook page of glc300 owners and almost everyone reported this kind of problem. For most of the people including me , it is still unresolved . I took my vehicle to dealer and they updated software but issue still persists.

When driving at 40 to 60 MPH and hit shallow pot hole or bump in the road the front wheels violently shake and the steering wheel (electric steering) violently vibrates for 5 to 8 seconds. Dealer checked the vehicle and claims there is nothing wrong with it but did turn off the "attention assist" setting from sensitive setting claiming it was the cause. The issue still exists but not as violent. I'm concerned of loosing control of the car/my safety. FYI: never experienced this issue with my previous car (same car two years older ,2020 GLC 300).

When driving at 40 to 60 MPH and hit shallow pot hole or bump in the road the front wheels violently shake and the steering wheel (electric steering) violently vibrates for 5 to 8 seconds. Dealer checked the vehicle and claims there is nothing wrong with it but did turn off the "attention assist" setting from sensitive setting claiming it was the cause. The issue still exists but not as violent. I'm concerned of loosing control of the car/my safety. FYI: never experienced this issue with my previous car (same car two years older ,2020 GLC 300).

I was involved in a severe front-end collision where my vehicle struck another vehicle with significant force. Despite the major impact, the front airbags did NOT deploy. The entire front end of the vehicle was crushed, including destruction of the radiator, damage to engine components, internal structural collapse, and leaking fluids. Based on the severity and direct frontal nature of the crash, airbags should have deployed but did not. As a result of the impact, I sustained a neck and upper shoulder injury and required medical evaluation. There were no warning lights or messages prior to the crash indicating any malfunction in the airbag or SRS system. The vehicle is available for inspection by NHTSA, the manufacturer, insurance, or an authorized Mercedes-Benz service center. This appears to be a possible failure of the airbag/SRS system during a qualifying collision.