2023 Mercedes-Benz C 300

When going into Reverse the passenger side mirror angles down to see curbs. When putting back into Drive it should be going back up to normal angle, but 20% of the time it does not go back up. If you're driving in the dark you may not know it's reverted back up and get into a car accident. Dealership said there are no issues and a technician stated it goes back up at +9 mph. I've gone over 30 mph driving on public street only to realize it late. I am hoping this gets publicity before an accident occurs due to a defective safety-comfort feature.

NHTSA ID

11699593

Incident

Nov 15, 2025

The contact owns a 2023 Mercedes-Benz C300. The contact stated that on occasion while driving at various speeds, the vehicle unexpectedly stopped without the brake pedal being depressed. There were no warning lights illuminated. The vehicle was diagnosed twice by the local dealer, and the contact was advised that the Forward Collision Avoidance sensors needed to be recalibrated; however, the failure persisted. The vehicle was taken back to the same dealer where the vehicle was inspected, and the contact was advised that further diagnostic tests were required to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 28,000. The VIN was not available.

NHTSA ID

11680376

Incident

Jan 13, 2025

Mileage

28,000 mi

My panoramic sunroof spontaneously exploded while driving down the highway, no external impact was made. The glass exploded from the inside out. It made a loud boom, it startled me on the highway resulted me to swerving on the road, which would have put me and other drivers at risk. There's plenty other MB drivers reported similar issues that stated. MB has also settled a class action lawsuit regarding such manner. UNKNOWN There were no warning signs prior to the event. The event spontaneous and sudden.

NHTSA ID

11678947

Incident

Aug 5, 2025

On 4 different occasions car brake assist activated causing car to come to an immediate stop and jerk. At stop light as I started to accelerate a left turn car came to an immediate stop almost causing the car behind hit rear end. Brake assist light activated. This happened twice. And twice when in reverse backing out of a parking space and backing into driveway. Dealership notified look at my car and stated they did not see anything wrong. 4th incident happened within 30 minutes after leaving Wilmington Mercedes Benz.

NHTSA ID

11674663

Incident

Jul 18, 2025

While driving at 60mph my panoramic sunroof completely shattered. Nothing at all hit the sunroof to cause it to shatter. If my sunshade cover had not been on, the glass would have fallen on me while operating my vehicle. This is not only dangerous but unacceptable. It was also a distraction that could have caused an accident. Mercedes did not make me aware of the class action lawsuit they have with the panoramic sunroofs, and I feel that was neglectful on their part. Upon inspection from a service advisor at a Mercedes Benz dealership, they told me something must have hit it (nothing hit it) and want to charge me $4,000 to fix it.

NHTSA ID

11662742

Incident

May 23, 2025

The contact owns a 2023 Mercedes Benz C300 equipped with Pirelli Tires, Tire Line: P Zero, Tire Size: 255/35/VR19, DOT Number: [XXX] . The contact stated while driving at undisclosed speeds, there was an unknown bumping sound heard. The contact pulled over and noticed that the passenger's side front tire was flat. The TPMS warning light was illuminated. The infotainment screen showed a reading of the tire 0 PSI. The contact noticed there was a hole in the tire and the side wall was damaged, and the rim was damaged. The contact depressed the SOS button but received no assistance. The vehicle was towed to the residence. The vehicle was taken to a tire center, but no assistance was provided. The contact called the local dealer and was provided information for the tire replacement. The dealer informed the contact that the tires on the vehicle were not correct for the vehicle. The vehicle was not repaired. The manufacturer was contacted, but no assistance was provided. The vehicle and tire failure mileages were 16,000. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11615020

Incident

Sep 2, 2024

Mileage

16,000 mi

This car has the driver assistance package including Active Speed Limit Assist which is supposed to automatically adjust the speed of the vehicle based on detected speed limits. However, it gets the speed limit wrong an excessive amount of the time sometimes resulting in the car suddenly decelerating which I consider to be a serious safety issue that could result in collisions. In my situation, I have experienced the car suddenly slowing to 40 mph for no reason in an area where the speed limit was 65 mph. I have also seen this problem documented on a number of blogs related to Mercedes-Benz vehicles. When I reported the problem to the dealership, I was told that it was a known issue and was encouraged to turn this feature off. I think Mercedes-Benz needs to fix this known issue for those of us who have cars with Active Speed Limit Assist.

NHTSA ID

11612912

Incident

Jan 4, 2023

While driving on the highway I had decided to tilt my sunroof open. When it opened the sunroof completely cracked/shattered discarding tiny particles of glass all over me. There were no previous compromising cracks nor did anything hit my pano sunroof causing this to happen

NHTSA ID

11606333

Incident

Aug 1, 2024

This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below. In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (“MBUSA”) is extending the warranty coverage on the Diagnostic Module for Tank Leakage detection (DMTL) in certain Model Year (“MY”) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 10 years/120,000 miles (vehicles certified as LEV II) and 15 years/150,000 miles (vehicles certified as LEV III), whichever occurs first, for the following condition: •Under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code (DTC) entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp (‘MIL’).

Complaint Audible "slurping" operating noise from the fuel tank Cause Conditions: • The fuel tank is around half full • The secondary chamber is almost empty. The suction jet pump suctions up small quantities of fuel and air. This results in vibrations and turbulence, which make noises. These noises may sound like slurping. The fuel pump and the drained secondary chamber amplify certain noises which can be loud or shrill. The viscosity of the fuel and the intensity of the fuel pump also impact the noises. • The fuel level is in the area of the saddle overflow in the primary chamber. The fuel mixed with air flows back into the secondary chamber. The noises may therefore be audible for longer • If the primary chamber is no longer in the area of the saddle overflow, the noises should disappear because the secondary chamber no longer receives fuel. • The area of the saddle overflow in the primary chamber is around +/- 2 liters of fuel volume (fuel gauge shows around half full). Remedy • Refill/drain approx. 5 liters of fuel; if the noise is reduced/is no longer present due to this, the circumstance specified above is present Further measures may cause a reduction in noises in the specified area: • In isolated cases, a fuel tank installed under stress may amplify the noises. The installation position of the fuel tank and the contact surfaces on the body-in-white should be checked here. To do so, release the fuel tank and refasten it, see WIS. • Replacement of component parts such as fuel tank/delivery module does not provide a remedy! If a similar noise is heard, but the tank volume is 3/4 or 1/4 and not 1/2 as described above, another circumstance is present

Complaint After an "Over the Air" update (OTA), FM or SDARS radio reception is limited; only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" (head unit), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.

Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to cracking of the microweld between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened. See also LI33.20-P-078406 Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove side shafts 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") with Molykote and leave to dry for "one hour" in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute).

Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit ("- -"). • Flashing when current vehicle speed is under speed limit. • Flashing between US speed limit symbol and European speed limit symbol. NOTE: • Verify that the concern falls under one of the attachment videos. If not, then it is outside of the scope of this LI. • This also does not cover "Traffic Sign Inoperative" messages on the instrument cluster. Cause There are two identified reasons for this concern: 1. Country code information stored incorrectly at a particular geographic latitude range. 2. Incorrect reference data when the vehicle is started and a GPS signal is not immediately available. Remedy Do not replace parts. Please open a TIPS case to the Body/Chassis/Entertainment inbox but read the below carefully: • The vehicle must be exhibiting the concern as shown in the attachment videos. • The vehicle DOES NOT need to be at the dealer, nor does it need to be brought into the dealership. • If the geographic location is known, it is very important that it is provided. • Provide any pictures or videos, if available. A new software for the head unit is scheduled for tentative release in Q3 2026.

Complaint Creaking noise, in irregular sequence when driving slowly in combination with slight steering movements and/or Creaking/crackling noises from the area of the wheel bearing on the front axle when cornering/ maneuvering. Sound file attached for comparison. MUST match noise for proper diagnosis. NOTE: Steering functionality is not affected. Cause Contact area between wheel bearing and steering knuckle. See also: LI35.30-P-058566 (Throttle Lift-Off Noise - Rear) LI33.30-P-056665 (Throttle Lift-Off Noise - Front) LI40.10-P-059248 (Wheel cracking noise when cornering) Remedy 1. Perform Operation A and evaluate by testing vehicle. 2. If noise is still present after re-testing: • If 192/232 chassis, verify FIN is in the listed range below in "Operation B" and perform. • If not 192/232 chassis or vehicle is a 192/232 not in the listed FIN range, additional verifications of where the noise is coming from are needed. Use multiple channel NVH method to narrow down location. Verify the LI's listed above were completed or if there are other similar noises associated with the chassis (Example: 192/232 also has under panel noises and an associated LI). Operation A: 1. Clean contact surfaces of wheel bearing and steering knuckle with brake cleaner as seen in the attached pictures. NOTE: The front area of the wheel bearing and the seals must not come into contact with the cleaner, otherwise, the sealing rings will be damaged. 2. Clean threads of wheel bearing mounting. 3. Thinly coat contact surfaces of wheel bearing, steering knuckle, and axle mating face with Molykote (annular joint grease). See the attached steering knuckle and wheel hub pictures for reference. NOTE: Axle mating face greasing is also covered in LI35.30-P-058566 and LI33.30-P-056665. Operation B (Only applies to 192 and 232 in listed FIN range): Only affects vehicles up to FIN end number: • Model series 192: xxx xxx xx 002 876 • Model series 232: xxx xxx xx 022 312 1. Replace steering knuckle. 2. Wheel bearings do not need to be replaced.