2024 Mercedes-Benz GLC Complaints

UNKNOWN OR OTHER,LANE DEPARTURE,BACK OVER PREVENTION — Filed 07/13/2026

The vehicle presented multiple warnings/errors before shutting down on the street in traffic on June 23, 2026. Warnings such as Collision Detected, Blind Spot Assist and Exit Warning Inoperative, PRE-SAFE Inoperative, System Failure Detected, Service Required Do Not Shift Gear, along with various lights on the dashboard which includes the Check Engine Light. The vehicle was towed to local Mercedes Benz dealership which reported the issue was with a drive train module that required a software update, the update was performed and vehicle was returned to me on June 25, 2026. On June 28, 2026 the warnings Blind Spot Assist and Exit Warning Inoperative, and PRE-SAFE Inoperative messages returned. Then on July 13, 2026 the vehicle shut down completely again in the same manner and error messages as initially reported. The vehicle was then towed to another dealership who reported seeing the same error messages, however they have not been able to replicate the issue after resetting the software.

STRUCTURE — Filed 07/07/2026

The rear lift gate closes unexpectedly when standing behind the vehicle and loading or unloading the cargo area. The keyless soft close activates even though there is no foot movement, or when there is minimal movement. This happens without warning. On several occasions this has happened to me, and also to my wife. It has caused minor bruises, but more importantly we are both older and it has been difficult extricating ourselves and reaching the control to raise the gate again. While there have been no falls yet, it's only a matter of time before someone loses their balance or is hurt in some other way. This has been reviewed by the local dealer's service department who says there is nothing wrong. It has also been discussed with an engineer at Mercedes with no result.

ENGINE — Filed 04/25/2026

Check engine light (MIL) came on while driving and vehicle lost power. Would not accelerate. Had it towed to Mercedes Benz of Mrytle Beach. $8000 repair. Mercedes Corp would not help. This is a copy of a TSB (LI05.20-P-080257) for this issue: Complaint engine vibrations perceived at low rpm. Fault codes for the camshaft position of the intake camshaft (p001100, p001104, p001200) or exhaust camshaft (p001400, p001404, p001500) may be stored. Cause continuously fluctuating oil pressure in the central valve may lead to damage to the filter screen on the central valve. This can result in damage to the filter screen or the filter screen breaking loose. The resulting loss of oil pressure prevents proper adjustment of the camshaft adjuster. If the filter screen breaks loose, parts of it may settle in the camshaft adjuster or in the camshaft. If there are parts in the camshaft, they can pass through the oil supply bore to the last camshaft bearing (i.E., the first camshaft bearing behind the adjuster) and cause damage there. Remedy 1. In cases in which only the screen of the central valve is damaged and no metal particles are found in the oil filter, the following parts must be replaced: - always both central valves - the camshaft adjuster of the damaged central valve 2. In cases where the screen is completely missing and metal particles are found in the oil filter, the camshaft bearings must be checked. If any damage is visible there, proceed as follows: - both central valves - the camshaft adjuster of the damaged central valve - the camshaft bearing housing (camshafts are already included here) - oil change with oil filter

ENGINE — Filed 05/31/2026

While driving the vehicle the engine started running rough, check engine light illuminated and it would not accelerate above 40 mph. There are 29,100 miles on the vehicle, it's been serviced on schedule by Mercedes and is owned by me since new. It is especially concerning due to the acceleration topic which could have been catastrophic if I were trying to merge into traffic. Dealer service say the camshaft bearing needs to be replaced. It seems this is very premature for the mileage on the vehicle.

POWER TRAIN — Filed 05/13/2026

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.

VISIBILITY,STRUCTURE,FORWARD COLLISION AVOIDANCE — Filed 08/28/2025

My 2024 Mercedes-Benz GLC 300 has experienced multiple serious safety-related malfunctions involving several vehicle systems. In August, after picking up the vehicle from service, I placed my [XXX] grandson in his car seat, set my purse with the key inside the vehicle, and closed the rear door. The vehicle immediately locked all doors on its own, trapping my grandson inside in approximately 88-degree temperatures. I was unable to gain access for about 30 minutes. This created a dangerous child safety situation. Key fob periodically will lock you out of car. The following day, while driving approximately 35 mph with my [XXX] grandson in the vehicle, the car suddenly and violently applied the brakes and tightened the seatbelt without warning or any obstacle present. The vehicle came to a complete stop in the roadway. I later experienced bruising and increased neck pain afterward. I have also experienced repeated power liftgate malfunctions. While loading groceries, the liftgate failed to recognize my presence and closed on me unexpectedly, striking my head. The vehicle was brought in for service in November regarding this issue. Additionally, while driving on the highway, both side mirrors have suddenly folded inward without warning on several occasions, causing immediate loss of visibility and creating a serious driving hazard. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ELECTRICAL SYSTEM,STRUCTURE,FORWARD COLLISION AVOIDANCE — Filed 08/22/2024

The contact owns a 2024 Mercedes-Benz GLC 300. The contact stated that while driving at approximately 35 MPH, the brake was applied unexpectedly without the contact depressing the brake pedal. The contact stated that she was unsure if the forward collision system was turned on at that time. The driver's seat belt tightened, and she sustained a bruise on her left arm and soreness on her chest. Medical attention was required. The vehicle was taken to a dealer where they were not able to replicate the failure. On another occasion, while parked, the tailgate was opened as groceries were being loaded into the rear cargo area. The tailgate closed inadvertently and struck the contact's head. The contact sustained head and neck injuries, and medical attention was required. The vehicle was taken to a dealer where the failure was not able to be replicated. The manufacturer was notified of both failures and advised that the automatic tailgate closing feature could be removed from the vehicle. The failure mileage was 31,153

SERVICE BRAKES — Filed 03/31/2026

3/31/26 2pm After highway driving - 3 miles/35 mph tried to brake- Immediately something was wrong with the brake as and it felt spongy/mushy/unresponsive. Car did not slow until I pressed the brake fully to the floor. The car did stop &was alarmingly unresponsive. Around this time,noticed the white BRAKE light illuminated. Continued to drive - terrified. Had to brake VERY HARD to get car to slow/stop. at home, Quick google search had me try turning on and off parking brake - tied this 5-6 times and white BRAKE light went off and I could brake/stop car. Bought car to Mercedes for service for 4:20 appointment - expressing incredibly strong reservations to Will Bane -and fear about driving car. He assured me as it is braking it should be fine. 04/01/2026 -notified car was ready for pick up/text stated: "Service is complete, everything looked good on the inspection report. No codes in the system for the brake concern and the brakes are currently working as designed" at pickup - and prior in text to will bane - i expressed significant concern about future braking issues. was told it was a "software issue and they updated it" and given a card for roadside assistance There was a recall campaign (2026010002/25p5496612) and codes were cleared as part of this unrelated recall. Brake fluid exchange was performed PRIOR to brake diagnosis Bottom line - I have significant concerns about braking.

BACK OVER PREVENTION — Filed 09/01/2024

New car was purchased from Rocklin Mercedes in California. Soon after the rear back up camera kept opening and closing when the car was in drive and at random times. The was then taken into Autobahn Motors in Belmont California to have the problem checked. I was told Mercedes was working on a software fix at which time the service tech never wrote up the problem. In 2025 the car again was taken into Mercedes for service at which time I brought up the same issue and was told most newer cars have this problem and there is NO fix, even the loaner they gave me had the same problem.

POWER TRAIN — Filed 04/08/2024

The vehicle has an ongoing transmission downshifting malfunction. The powertrain unexpectedly downshifts while driving, causing sudden changes in speed and unstable vehicle behavior. The issue can be inspected at any time, as the defect occurs intermittently and has not been repaired. This malfunction puts my safety and the safety of others at risk because the vehicle can slow down abruptly or shift aggressively without any input from the driver. This can create dangerous situations in traffic, especially at highway speeds or during acceleration. The problem has been reproduced and observed multiple times by the Mercedes-Benz dealership. I have taken the vehicle to the service center repeatedly for this same issue. Most recently, the vehicle remained at the service center for 10 consecutive days, but the defect was not resolved. The vehicle has been inspected by Mercedes-Benz technicians on several occasions. Despite multiple repair attempts, the issue continues to occur. There were no warning lamps or dashboard messages prior to the malfunction. The issue first appeared months ago and has persisted despite repeated service visits and repair attempts.