Mercedes-Benz GLC 300 jerking problems

Filed Aug 21, 2026 · Wheels · CA

On XXX, my 2016 Mercedes-Benz GLC 300 was serviced at a Mercedes-Benz dealership for a B Service, including replacement of the rear brake pads and sensor. The rear wheel had to be removed to perform this work. On XXX, approximately 7 days later, my wife was driving the vehicle with our [XXX] son and his friend as passengers when the LEFT REAR WHEEL COMPLETELY SEPARATED from the vehicle while in motion on a public road. A truck was approaching from behind. The family narrowly avoided a serious collision. Police responded to the scene and an officer directed traffic while the vehicle was towed. The lug bolts were recovered from the roadway. The dealership's General Manager later asked me to return the lug bolts, which I did. The vehicle required repair of the wheel and hub assembly at a collision center. I was given no written explanation of why the wheel separated. Separately, after the XXX service I noticed a transmission problem that was not present before. On XXX it became dangerous: coming out of stops at traffic lights and stop signs, the transmission would slip into Neutral instead of engaging Drive, and after several attempts would drop directly into third gear with a hard jerk. This creates a serious risk of being unable to accelerate away from a stop in traffic. I documented this on video and provided it to the dealership. No injuries have occurred, but both incidents were near-misses with a high risk of a crash or injury. I am reporting this so the potential defect and the quality of the safety-related service are on record. I have photographs and video from the wheel-separation scene, the transmission video, the service records, and related documentation available on request. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 27, 2026 · Transmission · CA

While driving my 2024 Mercedes-Benz GLC 300 on California highways, the vehicle has repeatedly experienced sudden uncontrolled deceleration, unexpected transmission downshifts into 2nd gear, severe transmission jerking, and complete loss of accelerator response. The first major incident occurred on March 7, 2025, while traveling on Interstate 5 at approximately 70 mph. The transmission suddenly jolted and downshifted directly into 2nd gear. The vehicle immediately lost power and slowed to approximately 20 mph without warning. I exited the highway and restarted the vehicle before it temporarily resumed normal operation. A second major incident occurred on May 7, 2026, while driving on Interstate 5 near Flag City, California at approximately 65 mph. The vehicle suddenly decelerated uncontrollably to approximately 20 mph. The transmission again shifted directly into 2nd gear, and the accelerator pedal became completely unresponsive. I was forced to make an emergency stop on the shoulder of the freeway with hazard lights activated due to the risk of being rear-ended by high-speed traffic and trucks. A third incident occurred on May 13, 2026, while accelerating onto Highway 99 in Modesto, California. During a shift from 4th to 5th gear, the transmission jerked violently and the vehicle suddenly lost power while merging into highway traffic. The vehicle has been taken to Mercedes-Benz of Stockton multiple times for diagnosis and repair attempts. The dealership has performed software updates and extensive testing, and dealership personnel have personally verified the transmission defect during road testing. Mercedes-Benz engineering has also become involved in the diagnosis process. However, the defect remains unresolved. This defect creates a serious highway safety hazard due to sudden loss of propulsion, uncontrolled deceleration, and loss of accelerator response while driving at freeway speeds.

Filed Nov 21, 2025 · Transmission · 60,000 miles · NY

The contact owns a 2019 Mercedes-Benz GLC300. The contact stated that while shifting from reverse to drive, the vehicle stalled and remained in neutral. After the vehicle stalled, the vehicle took approximately 8 minutes before the vehicle could be shifted into drive. Once in drive, the vehicle would jerk and shift to D3 before accelerating. The check engine warning light would illuminate while in reverse. The vehicle was taken to the dealer, who diagnosed a transmission failure due to a malfunctioning valve body and low pump pressure. The dealer confirmed that the VIN was not under recall and that the issue was not covered under warranty. The vehicle was not repaired. The contact informed the manufacturer of the failure, and a case was opened. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 60,000.

Filed Oct 30, 2025 · Steering · FL

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.

Filed Sep 16, 2025 · Acceleration · NY

While pulling into a parking spot with my foot hovering above/on the break, the car lurched forward as if someone had floored the gas pedal. As my foot was already on the break, I slammed down onto the break and the car came to a stop, several feet ahead of the top of the parking spot, and into the woods. I called roadside assistance for the vehicle to be towed to the dealership for repair, as I did not find it safe to drive it. The dealership was unable to replicate the issue, but they told me that due to the severity of the issue, they weren't supposed to check it themselves. Instead, I needed to report a case to Mercedes Corporate and the communication from here would be handled directly between corporate and myself. It's been over three weeks since this occurred, and I have not received communication that the car has been tested further, or any next steps. The car is at the dealership. It's also important to note that this same issue also happened months before, while backing out of a parking spot in reverse. I didn't report it because it was a confusing thing to happen and I couldn't believe a car would gas on it's own. When it happened a second time, I knew it was a problem. This was not a case of user error or the floor mat being in a wrong position. What component or system failed or malfunctioned, and is it available for inspection upon request? Speed control / yes How was your safety or the safety of others put at risk? The car spontaneously accelerated and could have caused harm if people or structures were in its path. Has the problem been reproduced or confirmed by a dealer or independent service center? Has not been reproduced Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Not that I know of Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No

Filed Aug 28, 2025 · Driver assistance, Electrical · 2,000 miles · NJ

The contact owns a 2025 Mercedes-Benz GLC300. The contact stated that while driving approximately 30 MPH, there was an abnormal grinding sound coming from the vehicle. The contact stated that the brake assist suddenly activated and the vehicle came to an abrupt stop, causing the seat belt to immediately retract and lock. The contact was slightly jerked from the abrupt stop. The contact stated that a warning light with a red triangle with an image of a crash in the center was illuminated. The contact stated that after starting the vehicle, the infotainment center and the instrument panel were completely black. The vehicle was restarted several times before both systems started operating as needed. The failure occurred twice; however, the second time, the contact had to turn off and restart the vehicle for approximately an hour before the infotainment center and instrument panel became operational. The vehicle was taken to the dealer, who performed a software update for the infotainment center. After the software update was completed, the contact became aware there were other electrical systems that failed intermittently, including the voice activation system. The vehicle was returned to the dealer and the contact was informed that the front driver’s and passenger’s sides sensors were too low and there was no reason for the notification to become activated. The vehicle was not diagnosed or repaired. The manufacturer was informed of the failure, and a case was opened. The failure mileage was approximately 2,000.

Filed Dec 10, 2024 · Engine · 40,000 miles · FL

The contact owns a 2020 Mercedes-Benz GLC300. The contact stated that while stopped at a red light, the vehicle started shaking and jerking. The check engine warning light was illuminated. The vehicle was taken to a dealer where it was diagnosed that the cylinder head needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 40,000.

Filed Nov 14, 2024 · Electrical, Engine · FL

When stopped at a light or stop sign, Vehicle will Jerk forward as If hit from behind. Very surprising and dangerous. Very intermittent. The has happened many times. Vehicle will at times have rough downshifts. Ie. overdrive (9th) to (8th) gear. also intermittent. This has happened multiple times. Vehicle was taken to the dealer twice for a total of 50 hours in the shop. The first service time no problem was found, diagnostics did not show problem. Aug 22 to Aug 30, 2024. The second service time Oct 3 to Nov 14, 2024. Problem was duplicated by the technician. Vehicle diagnostics still did not show a problem. Technician replaced the transmission valve body, did various software checks at the request of the factory. The engine control unit was then changed based on data supplied to the factory. At this point technician checked the car and dealers believes car is fixed. Vehicle has been returned to us on Nov 14 2024. We have requested the vehicle be bought back or replaced.

Filed Dec 6, 2023 · Fuel system · NY · crash · 1 injury

The contact owned a 2022 Mercedes-Benz GLC300. The contact stated while driving approximately 30 MPH, the steering wheel lurched to the right direction. The contact stated no warning light was illuminated. The contact stated that the front passenger side of her vehicle crashed into a parked vehicle hitting the left passenger door and tire wheel. The contact stated that the vehicle stopped and the engine stalled. The contact stated she had to kick the driver's side window out to exit the vehicle. The contact later saw that she had bruising on both her thighs and shins, but no other injuries. The police arrived on the scene and had the vehicle towed to an impound lot. The contact had not taken the vehicle to a local dealer or repair center. The vehicle had not been diagnosed or repaired. The contact had received a recall letter from the manufacturer for the federal safety agency Campaign Number: 23V445000 (Fuel System, Gasoline) and related the failure to the recall. The manufacturer was informed of the failure. The failure mileage was unknown.

Filed May 3, 2023 · Electrical, Engine · AR

Odometer reading more miles then driven (may have been tampered with altered) There is an electrical issue The computer required to be reprogrammed has not been done yet While driving the vehicle completely stop accelerating in the middle of traffic on the interstate placed my life in danger especially because traffic was moving rapidly the vehicle was jerking horribly also several codes came on when the service light came on also needed a pcp vale hose system they never repaired it i asked to have it repaired they agreed and then stated the vehicle had to many issues was sending to auction but yet reselling the vehicle still have not repaired completely this could be dangerous