2022 Mercedes-Benz GLC 300 problems

Filed Nov 5, 2026 · Transmission · NY

See attached document for complaint.

Filed Nov 1, 2026 · Engine · TX

My 2022 Mercedes-Benz GLC 300 experienced a significant cooling-system malfunction involving repeated low-coolant warnings, engine overheating, and substantial coolant leakage. Approximately two weeks before the overheating incident, the vehicle began displaying low-coolant warnings. On October 22, 2026, after driving normally and stopping to refuel, I restarted the vehicle. Approximately five minutes later, the dashboard displayed a red warning stating, "Coolant Too Hot. Stop Vehicle. Turn Engine Off." The engine temperature gauge approached the maximum range. I immediately sought a safe location to stop and turned off the engine within approximately one minute of the warning. After allowing the vehicle to cool, I discovered the coolant reservoir was nearly empty. I replenished the coolant, and the warning temporarily disappeared. However, following limited additional driving, the low-coolant warning returned. I subsequently observed substantial coolant leaking beneath the vehicle while it was parked with the engine turned off. The leakage appeared in multiple locations underneath the front and center portions of the vehicle. I documented intermittent dripping followed by sudden streams of fluid, resulting in several visible puddles. This malfunction presents a safety concern because the vehicle experienced rapid overheating during normal operation, requiring an immediate stop to avoid possible engine damage or loss of vehicle operation in traffic. The specific failed component has not yet been identified. The vehicle has not yet undergone a professional diagnostic inspection, but the symptoms and external leakage have been documented through photographs. The vehicle is available for inspection. I am requesting that the federal safety agency investigate whether this cooling-system failure represents a broader safety concern affecting similarly equipped Mercedes-Benz vehicles.

Filed Oct 12, 2026 · Airbags · FL · crash · 4 injuries

I am reporting a potentially serious vehicle safety issue involving a 2022 Mercedes-Benz GLC after a fatal crash. I was seated in the left rear seat. One occupant died and multiple people were injured. According to the Florida Highway Patrol crash report, the left curtain air bag was listed as “Equipped; Not Deployed,” while the right curtain air bag was listed as “Equipped; Operative; Deployed.” I suffered serious injuries while seated on the same side where the curtain air bag did not deploy. Before the crash, I remember hearing an unusual metallic rattling/clanking noise from the vehicle. I do not know what caused the noise or whether it contributed to the crash, but it occurred before impact. A family member later reported this pre-crash noise to the vehicle’s insurer. Law enforcement indicated that the vehicle’s event data recorder (EDR/“black box”) would be downloaded, but the crash report later stated “EDR Downloaded: No.” To my knowledge, the EDR data was never retrieved or preserved. The insurer later sold the vehicle as salvage before I was able to arrange an independent defect inspection, so the vehicle is no longer available to me for examination. I am not claiming that a defect has been proven. I am asking the federal safety agency to review whether the documented left-curtain nondeployment, in a crash severe enough to cause a fatality and multiple injuries while the opposite curtain air bag deployed, warrants investigation of the air bag/restraint system or another vehicle component. I am also asking the federal safety agency to consider the pre-crash metallic noise and the loss of access to the vehicle and EDR data when evaluating this complaint. Because the vehicle and EDR evidence may no longer be recoverable, I respectfully ask the federal safety agency to evaluate this complaint promptly and compare it with any similar air bag, restraint-system, sensor, or electrical complaints involving this model.

Filed Oct 1, 2026 · Fuel system · GA

The vehicle has experienced two separate incidents of significant loss of power/acceleration. First incident – January 2024, Clarksville, TN: While driving downtown, the vehicle suddenly lost significant power and could not provide normal acceleration. The estimated remaining range was approximately 50 miles. The vehicle was subsequently inspected/serviced by Mercedes-Benz/dealer personnel, but the underlying cause was not conclusively identified or resolved. Second incident- [XXX] [XXX]: While driving in the first lane of [XXX], the vehicle suddenly lost significant power/acceleration when the estimated remaining range was approximately 75 miles. There were no warning alarms or messages before the loss of power. My wife and child were in the vehicle. The vehicle could not provide normal acceleration in highway traffic, creating an extremely dangerous situation. The incident nearly resulted in a serious traffic accident, and my wife had to take immediate action to help avoid a potential collision. The vehicle was subsequently inspected by Mercedes-Benz/dealer personnel, but the specific loss-of-power condition was not conclusively reproduced or confirmed under the circumstances in which it occurred, and the underlying cause was not identified or resolved. The vehicle has therefore experienced this type of serious power-loss condition twice despite service attempts. I can no longer safely drive or intentionally test the vehicle to reproduce this condition. Attempting to drive until approximately 75 miles of remaining range could cause another sudden loss of power and potentially result in a serious accident. I will not intentionally recreate a potentially dangerous failure on a public highway with my family or other motorists at risk. I am reporting this because unexpected loss of power while traveling on a highway presents a serious safety hazard and potential collision risk. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 27, 2026 · Fuel system · CA

After recalls performed trouble code P2402 EVAP leak still is present and check engine light is on

Filed Aug 25, 2026 · CA

Rear hatchback for 2026 Mercedes GLC sensors

Filed Aug 23, 2026 · Brakes, Electrical · IL

Vehicle: 2022 Mercedes-Benz GLC 300 4MATIC Component: Electronic Parking Brake (EPB) / Service Brakes Summary of Complaint: This vehicle has an ongoing, unresolved Electronic Parking Brake (EPB) defect. The amber EPB warning light has recurred multiple times, including most recently after a $3,000 dealership repair intended to correct this exact fault. Timeline: 1.Following a brake pad replacement, the vehicle experienced an EPB failure, brake fluid loss, and a gear shift interlock lockout — leaving the vehicle inoperable. 2.The vehicle was taken to a Mercedes-Benz dealership for repair. This resulted in a dispute over unauthorized work performed and a request for goodwill coverage tied to a known Mercedes-Benz EPB recall. 3.I paid approximately $3,000 to the dealership for a repair specifically to resolve the EPB fault. 4.Approximately a few weeks after this paid repair, the same amber EPB warning light returned, indicating the underlying defect was not resolved. Safety Concern: The EPB is a safety-critical system. Repeated, unresolved failure of this system — including a prior incident involving brake fluid loss and a gear shift interlock lockout that left the vehicle inoperable — represents a real risk of parking brake failure and loss of vehicle control/immobilization in normal use. Additional Notes: •This defect appears connected to a known Mercedes-Benz EPB recall. •I have photo documentation of the recurring warning light (dated) and the dealership repair invoice for the $3,000 repair. •I have an open case with Mercedes-Benz Customer Assistance regarding this issue.

Filed Aug 8, 2026 · Engine, Fuel system · NY

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 (the federal safety agency 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."

Filed Aug 5, 2026 · Acceleration · IL

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.

Filed Jul 3, 2026 · Brakes, Electrical · IN

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.