MERCEDES-BENZ Complaints

Component/system that malfunctioned: The braking and acceleration system, including the collision assistance (driver-assistance/automatic braking) feature. The vehicle is available for inspection upon request. How safety was put at risk: The car lags when braking and at times accelerates unexpectedly. On one occasion, the collision assistance system—which is designed to brake—instead caused the vehicle to accelerate. The most dangerous incident occurred when the car accelerated on its own into an intersection, nearly causing a collision. Reproduced/confirmed by a dealer or service center: The vehicle was taken to the Mercedes-Benz dealer twice regarding this issue. On both visits, the dealer reported that they found no problem. The fault has not been confirmed or reproduced by the dealer. Inspected by manufacturer, police, insurance or others: Inspected by the Mercedes-Benz dealer on two occasions (no fault found). UNKNOWN whether the manufacturer's engineering team, police, or insurance representatives have inspected the vehicle—to my knowledge, they have not. Warning lamps, messages, or symptoms prior to failure: UNKNOWN / none noticed. No warning lamps or dashboard messages were observed before or during these events. The symptoms (braking lag and unexpected acceleration) have been consistently noticed by all three drivers of the vehicle.

At approximately 87,000 miles, my 2021 GLE350 (M264 2.0T engine) experienced a severe engine misfire resulting in a flashing check engine light, rough idle, engine shaking, significant loss of power, and near-stall condition. The vehicle was taken to Speedhaus Automotive (Newbury Park, CA) where all four ignition coils and spark plugs were replaced. Total repair cost was approximately $635. This failure pattern is consistent with the documented M264 exhaust valve seat wear issue acknowledged by Mercedes-Benz technicians. A Mercedes dealer service report on an identical 2021 GLE350 explicitly states: "COMMON ISSUE FOR EXHAUST VALVE SEATS TO WEAR — KNOWN ISSUE WITH 260 AND 264 MOTORS." Mercedes-Benz has extended the warranty on the M260 engine (transverse variant) for this identical failure mode but has not extended it for the longitudinally-mounted M264 despite the same defect being present. Repair costs for full cylinder head failure on the M264 are being quoted at $6,000–$13,000. I am requesting NHTSA investigate whether a safety recall is warranted for the M264 engine across all affected GLE350, GLC300, C300, and E350 vehicles.

My 2015 C300 W205 failed at its state inspection today due to a rusted through rear subframe. I understand that the W204 warranty on this was extended to 20 years/unlimited miles but the W205 was not. I have contacted Mercedes customer care for a potential goodwill repair since this seems to be a known issue with class actions pending. This should not be failing and it’s unclear why Mercedes did not include all models with the same design in its extended warranty. The costs could be up to $7k.

The contact owns a 2022 Mercedes-Benz EQB 300. The contact received notification of NHTSA Campaign Number 26V073000 (Electrical System); however, the part to do the recall repair was not yet available. The local dealer was contacted; however the vehicle was not diagnosed or repaired. 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. 

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.

The 2025 c300 rwd sedan was parked outside for about an hour. After getting back into the car and reversing, the rear camera would not display. The camera/parking interface was activated however there was an error symbol where the camera image is displayed, with a camera crossed through. Restarting the car, shifting back into drive, and stowing the camera did not restore the rear camera image. The camera deploys upon reversing and the lens/housing is clean. The image is not displayed in the driver display. This is unacceptable and another software issue that causes intermittent equipment failure, disabling vital safety systems and greatly increasing the risk of a collision.

AMENDMENT TO ACTIVE CASE 11723015. CRITICAL AIRBAG & SAFETY DEFECTS. This files a safety defect amendment to open case 11723015. Diagnostic scans confirm central data bus network collapse on VIN [XXX] has migrated into safety-critical occupant restraint and visibility modules, violating 49 U.S.C. § 30118. I. AIRBAG & RESTRAINT HAZARDS Scans from [XXX], document active faults: DTC U042782: "Implausible data received from Electronic Ignition Lock." The SRS module receives corrupted data from the failed ignition gateway, creating risk of airbag non-deployment. DTC B007A13: Passenger seatbelt pre-tensioner open circuit; occupants are unprotected against crash displacement. DTC B11FA4B: Active "Overtemperature" faults in heating elements indicate localized thermal short-circuit risk. II. HARDWARE DECAY Physical teardown confirmed structural oxidation on the central gateway motherboard and corroded connector pins. Modular swaps failed; network lock code U016887 returned within 8 months. Raw dealer records are available for federal inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The panoramic sunroof unexpectedly shattered while the vehicle was parked in my driveway overnight. There was no collision, impact, weather event, vandalism, or any other external cause that could explain the failure. The damaged sunroof remains available for inspection upon request, and security camera footage from my property shows no outside influence that could have caused the glass to break. The unexpected failure of the panoramic sunroof created a significant safety risk. Had this occurred while I was driving, shattered glass could have fallen into the vehicle, potentially causing injury to me or my passengers, obstructing visibility, or leading to a loss of control of the vehicle. The fact that the glass failed without warning while the vehicle was stationary raises concerns about the safety and structural integrity of the panoramic sunroof system. The dealership claims that they inspected the vehicle and confirmed that the panoramic sunroof was shattered. However, they did not want to provide me with the inspection report and denied the claim responsibility and have not acknowledged the failure as a manufacturing defect. The vehicle has been inspected by the dealership. No police report was filed because there was no accident, vandalism, or criminal activity involved. At this time, the manufacturer has not independently inspected the vehicle to my knowledge. As I have seen and read online, there has been dozens of similar cases with Mercedes regarding this issue and I believe i have read there is a lawsuit. No warning messages, no recalls, no unusual noises, cracks, chips, leaks, or other symptoms were present prior to the failure.

Shortly after we took possession of the car, I noticed that the warning that I was not holding the steering wheel would light up when I was holding the wheel with both hands in the 10-2 position. Flipping my fingers while continuing to hold the steering wheel was sufficient to switch the warning off. Also I was frequently being advised that the steering assist was inoperative and that the stop and go assist was inoperative. On August 21, 2025 when I was driving in I95, the various warnings described above appeared on the screen. The hands warning sign would not go off although I was holding the wheel correctly. A warning chime began and then a message that the system was initiating an emergency stop. I accelerated briefly and the warning disappeared. On August 28, 2025 I took the car to the dealer for assessment. I was advised that the car required a software update (Invoice no. 118573). I picked the car up on September 2, 2025. The following morning I received a telephone call from Mercedes Benz advising me that “Germany” had indicated overnight that the steering wheel needed to be replaced and I would be advised when that was available. I took the car back on September 11 for the steering wheel to be replaced. The previously described problems recurred other than the warning that an emergency stop was being initiated and I took the car back on December 12, 2025. Another new steering wheel was fitted. The problems persisted and the car was taken back. On this occasion a software update was performed. In late March 2026 when I was driving an a busy two lane road, the typical problems recurred but flipping my fingers did not work and the initiating an emergency stop warning appeared. Acceleration was not an option and there was no immediate place for me to pull off. I removed both hands from the steering wheel and the warnings disappeared. I regard these two emergency stop warnings as representing a significant safety issue.

The contact owns a 2024 Mercedes Benz E. The contact stated that while the vehicle was parked, and started, the instrument panel and infotainment screen became blank. No warning indicators or audible assistance and other vehicle assistance were not able to display due to the failure. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The approximate failure mileage was 21,000.