Mercedes-Benz GLC-Class Complaints

782 consumer complaints on file.

#11761658September 2, 2026
SERVICE BRAKES, ELECTRICAL SYSTEM, ENGINE
My 2025 Mercedes-Benz GLC 350e displayed a “48V battery malfunction” warning on or about July 1, 2026, while the vehicle was less than one year old. The vehicle was taken to an authorized Mercedes-Benz dealership and remained there until approximately July 20. Mercedes-Benz USA became involved, and the dealership ultimately stated that the malfunction had been corrected through a software update. The 48V battery was not replaced. I have not received documentation clearly identifying the specific software update, campaign, operation number, underlying failure mechanism, or pre- and post-repair diagnostic results establishing that the reported malfunction was caused and resolved by software. I am therefore unable to determine whether the battery or another component of the 48V system was defective, or whether the warning was merely cleared. In late August, I also heard a new and pronounced whirring sound near the left-front area of the vehicle after charging. A different authorized dealership charged the high-voltage battery to 100%, attempted to reproduce the sound, and found no charging-system fault codes or abnormal noise. It characterized the sound as normal post-charge cooling operation and performed no repair. I am submitting this complaint because of the original 48V malfunction, the lack of documentation identifying exactly what failed and what software remedy was performed, and the possible relevance to a previously closed NHTSA investigation involving Mercedes-Benz battery-related concerns. Please associate this complaint with any applicable closed investigation and evaluate whether this incident constitutes additional relevant field evidence.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11761172August 31, 2026
ENGINE
My check-engine light recently illuminated, and diagnostic testing identified fault code P06DA00, relating to the oil pump control valve circuit. I have been quoted over $5,000 to replace the oil control valve and oil pump harness. I was quoted the following by Mercedes Servuce in Manchester, NH- Oil Pressure Regulator Valve: need to remove lower oil pan only to access oil control valve and replace the valve and sub harness. $5013.52. This is a known issue. My vehicle has been well maintained, and I have been advised that it is otherwise in excellent mechanical condition. I intend to keep and drive this vehicle for many more years, which makes it particularly disappointing to encounter a repair of this magnitude for a component that is not considered a routine maintenance or wear item.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11760688August 30, 2026
ENGINE, FUEL/PROPULSION SYSTEM, POWER TRAIN
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11760363August 28, 2026
UNKNOWN OR OTHER
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.
Crash:
No
Fire:
Yes
Injuries:
0
Deaths:
0
#11760501August 28, 2026
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
What component or system failed or malfunctioned, and is it available for inspection upon request? The Forward Collision Avoidance / Active Brake Assist (Automatic Emergency Braking) system failed by falsely identifying a non-existent threat and initiating uncommanded emergency stopping. The vehicle and its onboard control modules are fully available for physical and diagnostic inspection upon request. How was your safety or the safety of others put at risk? While traveling at approximately 35 mph, the vehicle suddenly executed maximum emergency braking with zero warning and no preceding obstacles, vehicles, pedestrians, or road hazards present. The violent deceleration caused maximum seatbelt restraint locking force, resulting in sudden physical impact trauma to a 6-month pregnant passenger and acute dizziness/disorientation for both occupants. This malfunction creates a severe, immediate risk of high-speed rear-end collisions from trailing traffic and unexpected loss of vehicle control. Has the problem been reproduced or confirmed by a dealer or independent service center? Not yet. The vehicle has not yet been serviced or inspected by a dealer or independent service center following this event. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? No. Neither the manufacturer, police, insurance representatives, nor third-party investigators have inspected the vehicle or component since the incident occurred. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There were no warning lamps, error messages, chime alerts, or functional symptoms prior to the sudden brake activation. The Active Brake Assist system triggered immediately without prior warning.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11760063August 27, 2026
FUEL/PROPULSION SYSTEM
After recalls performed trouble code P2402 EVAP leak still is present and check engine light is on
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759873August 26, 2026
SERVICE BRAKES, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
2. Service Department Misconduct —XXX Appointment On XXX, I brought my vehicle to the dealership’s service department for a pre-scheduled and confirmed appointment regarding a safety-related warning involving the emergency brake system. Despite having provided a full description of the issue at the time of booking, I was informed upon arrival that the diagnostic process would take more than five hours. When I asked about a loaner vehicle — standard practice at Mercedes-Benz dealerships in cases of extended service — I was refused, even though five courtesy vehicles were visibly parked on the lot and at least two other customers who arrived after me were provided loaners and expedited service that same day. I was made to wait in the lobby for the entire day. At approximately 5:00 p.m., just before closing, and despite no diagnostic work having been performed on my vehicle, a loaner vehicle was suddenly made available to me. This inconsistent and apparently discriminatory treatment in the allocation of loaner vehicles and service priority is unacceptable and warrants review. 3. Lack of Communication and Missing Documentation Following Service The technician assigned to my vehicle, [XXX], told me he would call me on Monday, XXX, once diagnostics were complete. He did not call. Instead, I received only an automated text message on Tuesday, XXX, stating the vehicle was ready — with no phone call, no email, and no explanation or summary of the work performed, contrary to standard practice at other Mercedes-Benz dealerships I have used. When I called to follow up, the technician did not answer despite multiple voicemails. I called the service department directly and asked for a supervisor; none was made available. After approximately one hour of calling the main dealership line, a sales associate attempted to reach the service department on my behalf and also received no answer. I then reached the technician directly. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759874August 26, 2026
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING, FORWARD COLLISION AVOIDANCE: WARNINGS
The car went from 20 miles an hour and 35 miles an hour (happened 2 times) to a sudden hault like hitting a wall. The first time I had to restart the car. The second car, I had to return it to drive. A big X came up on the dashboard. I have owned the car 17 months. Both issues happened in the last 30 days. Nothing beefore. The car has 4415 miles on it. The dealer (Fletcher Jones) was unable to replicate). There was no warning. They told us it was our problem and we could report it to Mercedes Benz which we will do today.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759351August 25, 2026
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
While driving at slow speed (approx 27 mph) on an inclining road, the automatic braking system when off and abruptly slowed down the vehicle. Fortunately there was no one immediately behind my car and there was no apparent reason for the emergency braking. The sidewalk did have a person with a dog off to the right at the time but they were completely away from the car walking on a sidewalk. This could have been dangerous if someone was driving immediately behind my car.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11759362August 25, 2026
UNKNOWN OR OTHER
Rear hatchback for 2026 Mercedes GLC sensors
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758847August 23, 2026
SERVICE BRAKES, ELECTRICAL SYSTEM
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758716August 22, 2026
ELECTRICAL SYSTEM
Information screens; speed, gear etc. and middle screen, radio, gps, etc, go blank. Screens are black with no information. There’s also a popping sound happening in the background over the speakers. You can start the car and put it in gear and drive - but with no information in either computer screens. Safety issue for sure! After waiting approximately 3 hours, the 2 screens come on when car is started.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758634August 21, 2026
WHEELS
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)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11758163August 20, 2026
SEAT BELTS
The seatbelt latch does not fully release when you press the red button. It needs to be wiggled and then it eventually does release. This is an ongoing issue.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11757434August 17, 2026
SUSPENSION
The suspension has malfunctioned on a car with only 89,000 miles. Upon starting the car, the vehicle says to please wait while it is rising. However, when I drive it, a red alert says to stop driving because it's too low to drive, and the car looks very low and lopsided. This is a safety concern when driving on the highway and around town. This appears to be an issue on other Mercedes models, such as the 2020 model; please consider 2019 as a year of concern as well.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11755841August 10, 2026
VEHICLE SPEED CONTROL, SERVICE BRAKES, HYDRAULIC
The contact owns a 2025 Mercedes-Benz GLC 350E 4Matic. The contact stated that while driving 10 MPH and attempting to park the vehicle, the vehicle unintendedly accelerated. The brake pedal was depressed, but the vehicle failed to respond. The vehicle was uncontrollable and crashed into a fence. The driver’s side mirror, bumper, and door were damaged. The contact stated that the air bags did not deploy. The instrument panel had previously gone black before the crash and the vehicle previously failed to accelerate as needed. There were no injuries sustained. A Police report was filed. The vehicle was taken to the local dealer for two prior software updates. The vehicle was towed to the local dealer but was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 9,000.
Crash:
Yes
Fire:
No
Injuries:
0
Deaths:
0
#11755637August 8, 2026
FUEL/PROPULSION SYSTEM, ENGINE
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 (NHTSA 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."
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11755359August 6, 2026
POWER TRAIN
Vehicle experiences a severe, abrupt jerk/jolt during deceleration around the 5th-to-4th gear downshift. The issue occurs consistently when slowing down. Dealership verified the condition on Repair Order #1906625 and confirmed a transmission flaw. Dealer stated software is required from the manufacturer with no ETA for release. The abrupt deceleration creates unexpected cabin jolting during normal traffic slowing.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11754966August 5, 2026
VEHICLE SPEED CONTROL
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.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11754832August 4, 2026
ELECTRICAL SYSTEM
Moisture began collecting inside the left headlight assembly, even though the housing should be sealed. Over time, the condensation increased and the front left turn signal failed. The vehicle displayed warning messages for the turn signal, low beams, Blind Spot Assist, Traffic Sign Assist, and Active Brake Assist. The failed turn signal reduces the vehicle's visibility to other drivers and creates a potential safety hazard. A similar moisture intrusion issue was the subject of NHTSA Recall 22V-261 for certain 2021 Mercedes-Benz GLC vehicles, but this vehicle was not included in that recall despite exhibiting the same symptoms. The vehicle is available for inspection.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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