2021 Mercedes-Benz GLC 300 fuel system problems

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 Nov 3, 2025 · Fuel system · FL

The vehicle lost power and will not operate over 40 mph/2000 rpms

Filed Mar 3, 2025 · Engine, Fuel system · NC

High beam can't auto dim Fuel pump fail to operate, misfires, and shut down while driving

Filed Dec 4, 2024 · Fuel system · GA

The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while driving at low speeds, the vehicle lost motive power struggling to produce enough power to propel itself on a slight incline. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the fuel pump. The vehicle was not repaired. The vehicle was then towed to the dealer, who confirmed the diagnosis. The vehicle was not repaired. After investigating the failure, the contact related the failure to the federal safety agency campaign 23V880000 (Fuel System, Gasoline), but the VIN was not included. The manufacturer was notified of the failure; a case was opened, and the contact was referred to the federal safety agency hotline for assistance. The failure mileage was 80,000.

Filed Oct 4, 2024 · Engine, Fuel system · GA

Vehicle has a known engine failure. Leaking valve in Cylinder head. Cylinder 3 injector is faulty

Filed Jan 22, 2024 · Fuel system · 19,369 miles · CA

The contact owns a 2021 Mercedes-Benz GLC300. The contact stated that while his wife was driving in the rain approximately 35 MPH, the vehicle lost motive power and stalled. The vehicle was able to be restarted. The vehicle was taken to a dealer to be diagnosed. The contact was informed that the cylinder head needed to be replaced. The vehicle was repaired but the failure reoccurred. The contact believed that the failure was associated with the federal safety agency Campaign Number: 23V445000 (Fuel System, Gasoline) however, the VIN was not included. The manufacturer was notified of the failure. The failure mileage was 19,369.

Filed Dec 12, 2023 · Engine, Fuel system · FL

This is the 3rd incidence of this issue (July, Oct, Dec), but we have been advised that a software update is not yet available from the manufacturer. In all instances, we were travelling at a normal rate of in-city traffic (30-45 mph) and all of sudden the vehicle will not accelerate above 25 mph regardless of the position of the throttle. My dealer, Mercedes Benz of Tampa, advises that the problem can only be corrected permanently with a "software update" which is not yet available. This is a major safety issue, especially on the highway, as the vehicle could suddenly and unexpectedly be unable to accelerate, in fact, decelerates at random times without warning.

Filed Dec 7, 2023 · Fuel system · NC

The contact owns a 2021 Mercedes-Benz GLC300. The contact received notification of the federal safety agency Campaign Number: 23V445000 (Fuel System, Gasoline) 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. VIN tool confirms parts not available.

Filed Sep 27, 2022 · Electrical, Fuel system · KY

My car was bought new in October 2021 & I began having problems after having it for 6 months & the mileage at that time was about 4000 miles - it was in April 2022 & the check engine light came on & I had a loss of power to where it slowed down & would not go any faster than about 30/35 miles an hour going on a straight road way & no faster than about 10 miles an hour going uphill. The engine sounded funny as well. It had to be towed to the dealership for repair. This incident happened again a month later & it was towed to the dealership at that time. The next incident just happened this month (mileage=6620) & again it was towed to the dealership for repair. Same scenarios all 3 times. This last incident, I was told that it is glitch & they don't really know what is causing my car to basically go into "limp mode"; however, they are awaiting a software update that they expect will resolve the problem, but they are not sure when it will be available for installation & did not give me a timeline. In the meantime, I was given back my car as I was the 2 other times without a resolution or security that my car is doing to make it to & from my destination. The car is still under warranty & just under a year old now. I was told by the dealership that they have no other customers complaining of this problem & they feel it is very isolated. I asked them to reach out to their corporate office in hopes of making a deal with me as I have lost all confidence in the car, but they reported having no luck in reaching anyone to discuss my problem. The 3 incidents where the car had to be towed were very scary for me as other cars were blowing their horns at me because I could not accelerate & go any faster & when I was going up a hill - it was really bad. I was very lucky that all 3 times happened not far from my home & not on the interstate as the outcome could have been very bad for me in regards to my safety.

Filed Jun 19, 2021 · Fuel system · MI

Entered parked vehicle and noticed very strong gas fumes. Vehicle would not start. Looked under the vehicle and noticed very large quantity of gasoline on the ground. Vehicle was towed to Mercedes dealership in Rochester, Michigan. Diagnosis was an incorrectly installed fuel line bracket. New bracket was installed and problem was corrected.