2021 Mercedes-Benz GLC 300 problems

Filed Nov 4, 2026 · Transmission · 75,000 miles · CA

The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while driving 5 MPH, the vehicle stalled and lost motive power, with the check engine warning light illuminated. The vehicle was able to be restarted. The vehicle was taken to a service center, and the contact was provided DTC: P07B7. The contact was informed that the failure was associated with an internal transmission or software programming failure. The contact was informed that the transmission needed to be replaced and was referred to the dealer for additional assistance. The vehicle was scheduled for an appointment with the dealer. The failure mileage was approximately 75,000.

Filed Oct 5, 2026 · Driver assistance · 26,000 miles · GA · crash · 1 injury

The contact owns a 2021 Mercedes-Benz GLC 300. The contact stated while driving 10 MPH, the blind spot assist detection feature failed to function as intended. The contact stated while inspecting the vehicle, the contact confirmed that the blind spot assist feature was enabled. In addition, the failure occurred after the vehicle was taken through the car wash. The contact's vehicle crashed into another vehicle. The vehicle was driven to the residence. The contact sustained pain to the right shoulder, arm and hand. The manufacturer was made aware of the failure and a case was filed. The failure mileage was approximately 26,000.

Filed Sep 11, 2026 · Lights · GA

I own a 2021 Mercedes-Benz GLC 300. The vehicle developed moisture/condensation in the headlamp, and the affected headlamp subsequently failed. I took the vehicle to RBM of Alpharetta, an authorized Mercedes-Benz dealership. I was advised that corrosion was found in the affected headlamp and that the headlamp assembly requires replacement. On September 8, 2026, the dealership provided a repair estimate of $3,387.33. The vehicle had approximately 84,769 miles. Mercedes-Benz previously issued the federal safety agency Recall 22V‑261 / Campaign 2022050005 for certain 2021 GLC-Class vehicles because headlamp electrical connections may not have been sufficiently watertight, allowing moisture intrusion that could cause headlamp failure. My vehicle is the same year and model and is experiencing headlamp failure involving moisture and corrosion, but Mercedes-Benz states that my VIN is not included in the recall population. Mercedes-Benz Customer Care opened Case 23963515 and has declined coverage to date. I am concerned that my vehicle may be experiencing the same or a substantially similar moisture-intrusion defect as vehicles covered by Recall 22V‑261. A failed headlamp reduces nighttime visibility and presents a safety concern. I am requesting that the federal safety agency review whether similar headlamp moisture intrusion, corrosion, and failure may be occurring in additional 2021 Mercedes-Benz GLC 300 vehicles outside the original recall population.

Filed Sep 10, 2026 · Lights · FL

My vehicle is experiencing moisture intrusion caused by a defective headlight housing seal. The water intrusion has resulted in a short circuit and failure of the turn signal module within the headlamp assembly. I am aware of the federal safety agency Safety Recall 22V‑261, which addresses a substantially similar defect involving inadequate watertight sealing of the headlamp assembly that can allow moisture intrusion and lead to headlamp electrical failure. My vehicle is experiencing the same type of moisture intrusion and resulting electrical failure described in that recall. Because this failure appears consistent with the known safety-related defect identified by the federal safety agency, I am requesting that the vehicle and affected headlamp assembly be evaluated for recall-related or manufacturer-assisted repair rather than treated solely as a routine out-of-warranty component failure.

Filed Sep 4, 2026 · Electrical, Lights · OH

My 2021 Mercedes-Benz GLC 300 is not currently included in the federal safety agency Recall 22V‑261 / Mercedes-Benz Campaign 2022050005, but my vehicle is experiencing substantially the same defect described in that recall. Moisture/water entered the left headlamp assembly/electrical connection, resulting in condensation/water accumulation and damage/corrosion around the headlamp electrical module/connector. The headlamp system subsequently malfunctioned. Recall 22V‑261 describes a condition where the headlamp electrical connection may not be watertight, allowing moisture ingress and potentially causing headlamp failure. My vehicle appears to exhibit the same condition even though my VIN is excluded from the recall population. I am requesting that the federal safety agency review whether the affected population for Recall 22V‑261 may need to be expanded.

Filed Aug 30, 2026 · Engine, Fuel system · CA

The vehicle is experiencing an intermittent, sudden, and life-threatening drop into "limp home mode" while driving, creating an severe speed differential with surrounding traffic.First Incident (50,584 miles): The vehicle entered limp mode. Authorized Mercedes service center scanned the car, confirming Fault Code P019185 (Rail pressure sensor malfunction / signal above permissible limit value). The dealer applied an Engine Control Module software patch under Mercedes TSB LI07.70-P-078047.Second Incident (53,695 miles): Less than 3,000 miles later, the exact same sudden powertrain failure recurred. The vehicle drastically lost propulsion power immediately after exiting a high-speed freeway, leaving the driver in an incredibly vulnerable, unsafe position.The manufacturer's documented software remedy has completely failed to fix the underlying powertrain defect, leaving a known hardware component failure unaddressed while actively endangering vehicle occupants.

Filed Aug 28, 2026 · NJ · fire

While the vehicle was being operated normally, it caught fire. We were driving on a summer day in August. Conditions were humid, with temperatures in the mid-80s. The vehicle was on the return leg of an approximately 30-mile drive. Traffic was somewhat heavy, with speeds generally below 20 mph and occasional stops. We first noticed a slight burning smell, followed shortly afterward by a distinct puff of white smoke coming from under the hood on the passenger side, near the windshield. We immediately decided to stop the vehicle and get out. Within approximately 30 seconds, we observed the first visible flames. Within about one minute, the fire had spread rapidly and the vehicle was engulfed in flames. By approximately 3½ minutes, the entire front half of the vehicle had been destroyed by the fire. Parts of the vehicle were blown off during the fire, with some debris traveling across the roadway and into the nearby woods. Fortunately, there were no injuries because we recognized the danger and exited the vehicle quickly.

Filed May 20, 2026 · Engine · AL

While driving in my neighborhood at 25 MPH, my Mercedes GLC300 suddenly lost power and the check engine light illuminated. My car would no longer exceed 25-30 MPH, but I drove it straight to the dealership and they said it was a faulty cylinder head and will cost $10,000 to fix! After intense negotiations, they agreed to fix it for $4,205.58, which was better, but still, that’s a lot to pay for a manufacturer’s defect! My car is a 2021 with only 67,540 miles on it.

Filed May 5, 2026 · Engine · NJ

Getting P06DA trouble code meaning that there is something wrong with the oil pressure solenoid in the oil sump. this is a known issue where the wiring of the solenoid get frayed. cost of repair for the (cheap part) is $7,500 because of 18 hour labor involved. MB knows this is an issue with the wiring in the solenoid. I'm not sure if there is a fire risk because of the frayed wires.

Filed Mar 15, 2026 · Transmission · CA

The engine starts shaking, smell of gas car than stops while driving, could caused an accident and severely injured someone on the freeway. This is a major safety issue after further researching this particular issue MB of Canada issue a warranty letter extension for this particular but nothing for US.