2022 Mercedes Benz GLC 300 problems

ENGINE

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."

NHTSA complaint #11755637 — an unverified report by a vehicle owner.

FUEL/PROPULSION SYSTEM

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."

NHTSA complaint #11755637 — an unverified report by a vehicle owner.

VEHICLE SPEED CONTROL

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.

NHTSA complaint #11754966 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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.

NHTSA complaint #11748161 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11748161 — an unverified report by a vehicle owner.

SERVICE BRAKES

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.

NHTSA complaint #11748161 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

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.

NHTSA complaint #11742050 — an unverified report by a vehicle owner.

SERVICE BRAKES

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.

NHTSA complaint #11742050 — an unverified report by a vehicle owner.

ELECTRICAL 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.

NHTSA complaint #11736466 — an unverified report by a vehicle owner.

ENGINE

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.

NHTSA complaint #11736466 — an unverified report by a vehicle owner.

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.

NHTSA complaint #11736466 — an unverified report by a vehicle owner.

FUEL/PROPULSION SYSTEM

I was driving back to my house in york, PA. My car all the sudden changed the gear from “D” to “N”. My gas meter was showing 106 miles. my didn’t give sign or alert before it shifted the gear from D to N. I was driving on highway and this was major safety concern as I could have hit by cars coming on highway speed. We had this similar incident last year as well but we were at traffic light stopped so we didn’t realize that time that car shift the grear by itself. Once we fill the gas, we were able to drive back home but it was scary and big safety concern that car doesn’t give any notification or alert for low fuel and change gear all the sudden.

NHTSA complaint #11731548 — an unverified report by a vehicle owner.

ENGINE AND ENGINE COOLING

See attached document for complaint.

NHTSA complaint #11730878 — an unverified report by a vehicle owner.

FUEL SYSTEM, GASOLINE

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving at various speeds and depressing the accelerator pedal, the check engine warning light was displayed on the instrument panel. The vehicle lost power and was pulled over and restarted. The contact was almost involved in several crashes due to the failure. The vehicle was included in NHTSA Campaign Number: 23V445000 (Fuel System, Gasoline); however, the vehicle was repaired, and the failure persisted. The vehicle was taken to the dealer on several occasions, where the fuel pump, charcoal filter, and other various parts of the fuel pump were repaired; however, the failure persisted. The manufacturer was notified of the failure, and the contact was informed that the cylinder head would be replaced free of charge. The contact believed that the vehicle was unsafe to drive due to the failures. The vehicle was not repaired, and a loaner vehicle was provided. The failure mileage was unknown.

NHTSA complaint #11721373 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

My vehicle had check engine lights on throughout the last couple of years. Every time I bought it to the dealer, they ignored it and said the light went off. The machine doesn't pick up anything. Now the check engine light is on and the cylinder head and diagnostic head, something is wrong. They will fix the diagnostic head but not the cylinder head. The dealership knew there was ongoing issues but did nothing to correct it. The sales department already screwed me as well. The older models are recalled for the same issues and now the the newer vehicles like mine are having the same EXACT problem.

NHTSA complaint #11708865 — an unverified report by a vehicle owner.

ENGINE

The contact owns a 2022 Mercedes-Benz GLC300. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. There was a misfire coming from the engine, and the vehicle lost motive power. In addition, the check engine warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with spark plug failures, coils, and the transmission needed to be flushed. The vehicle was taken to an alternate dealer where the spark plugs and coils were replaced, and the transmission fluid was flushed. The contact stated that the failure reoccurred. The vehicle was then taken to an independent mechanic who was a Mercedes mechanic, where it was diagnosed with misfire codes in cylinders #1 and #4, leakage coming from exhaust valves in cylinders #1 and #4, low compression in cylinders #1 and #4, and there was a 75 percent leak in cylinders #1 and #4. The contact was informed that the complete head assembly needed to be replaced. The vehicle was not repaired. In addition, the contact stated that the vehicle was repaired under NHTSA Campaign Number: 23V445000 (Fuel System, Gasoline) on 11/2025. The contact stated that the failure began shortly after the recall repair was performed. The manufacturer was not made aware of the failure. The failure mileage was unknown.

NHTSA complaint #11705704 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

On Saturday 12/6/25, I put my 15 year old cat in his carrier in the back seat and closed the door. I got into my car and opened my garage door. I started my MBGLC300 and began backing my car out of my garage. As soon as the car rear end cleared the garage, I heard an explosion "BOOM", and the sound of breaking glass. I pulled back into my garage only to find the entire back window had exploded... all the glass was gone, and the back windshield wiper was dangling out of its housing from the pane (trim). I hit nothing! Nothing hit me! I got back into my car and drove the 10 minutes down the street to my vet's where he got his shot and I had him combed out (for any glass - thank goodness there wasn't any). While there, I phoned Dick Dyer Mercedes Benz (803.828.6952) at 8:57 AM,and spoke with Ryan Smith and told him I'd be down after the vet appointment. I pulled in at Dick Dyer service department shortly after 9:00AM. He said, "I've never seen anything like this." The whole glass was shattered into millions of tiny pieces. Smith got me into a Sedan and I drove home. On Monday Smith called to tell me Mercedes would not honor either my factory warranty (my car is a 2022) nor would my Extended Warranty (purchased at the time I bought my car) cover the $4,201.00 charge to repair. I'm a school teacher. I don't have that amount of cash. He said, "Ms. [XXX] , I want to believe you that you didn't hit anything, but I have to have proof." Therefore my only way to get the car repaired is to go through my insurance company. What a rip off! I totally thought Mercedes was a company that would stand by their products, especially those under not just 1 factory warranty, but a 2nd extended warranty. And, I got called a liar to boot. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11704230 — an unverified report by a vehicle owner.

BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

The rearview camera on my vehicle intermittently fails to function for unknown reasons, and the problem has recently become more frequent. For example, it may work normally when I first start the car in the morning and back out of my parking spot, but later the same day—such as when I arrive at work—the camera stops working completely. The display stays black and does not recover even after shifting between gears or restarting the system. After parking and locking the car for a while, the camera may start working again without any clear reason. Although I cannot recall the exact dates of the first occurrence, I have noticed a consistent pattern over time: the issue tends to appear during hot weather, particularly in summer. In recent months, the camera has almost completely stopped functioning. This unpredictable failure creates a potential safety hazard when reversing, as I cannot get help on the backup camera to provide visibility behind the vehicle.

NHTSA complaint #11698047 — an unverified report by a vehicle owner.

STEERING

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.

NHTSA complaint #11696510 — an unverified report by a vehicle owner.

STEERING

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)

NHTSA complaint #11696517 — an unverified report by a vehicle owner.

UNKNOWN OR OTHER

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)

NHTSA complaint #11696517 — an unverified report by a vehicle owner.

ENGINE

Multiple loss of power incidents while driving both on surface streets and highways. Causes vehicle to loss acceleration power, vehicle must be pulled over, shut down and restarted to regain power.

NHTSA complaint #11694859 — an unverified report by a vehicle owner.