2021 Mercedes-Benz CLA 250

the seal around my driver side rear light is not sealed correctly there is water precipitation in my lamp

NHTSA ID

11649297

Incident

Mar 18, 2025

On Friday, September 27, around 12 pm, while driving on i880S near Union City, California, something horrific happened. The sunroof of my 2021 Mercedes CLA 250, with just 49,000 miles, suddenly exploded without any warning. The sound was so loud and violent, it felt like a gunshot. I was immediately overwhelmed with fear and panic as I struggled to process what was happening. In my rearview mirror, I could see shards of glass scattering across the road behind me. When I looked up, I was horrified to see that the remaining glass was hanging in dangerous shards just above my head, barely held in place by the sunroof cover. I shudder to think what might have happened if that cover hadn’t been there—if it had fallen, I would have been covered in glass. And if there had been passengers or children in the car, the consequences could have been unimaginable. This experience left me deeply shaken and traumatized. I now have a lingering fear of sunroofs, and I no longer feel safe in my own vehicle. It’s not just the incident itself, but also the aftermath. When I brought the car to the dealer, despite still being under warranty, I was told this issue wouldn’t be covered. I was referred to MBUSA customer support, but after researching, I’ve seen numerous forums where others with Mercedes CLA and GLA models experienced the same problem and were similarly denied coverage. This is more than a manufacturing defect – it’s a significant safety hazard. This incident could have led to severe injuries, or worse. I urge the NHTSA to investigate this issue before someone gets seriously hurt or killed. This isn’t just about my car – it’s about ensuring the safety of all drivers and passengers in vehicles with sunroofs like mine.

NHTSA ID

11617574

Incident

Sep 27, 2024

Our car has lost power to accelerate on 4 occasions on the highway. The first instance was in October of 2023, the second instance was in November of 2024 (and was brought immediately to the dealership and they said the fix wasn't available yet), the third instance was in March of 2024 and the most recent incident occurred in June of 2024. For example, the car will be moving at a speed of 60 mph and it will suddenly start flashing lights in the car with a warning signal that the "car is unable to reserve". The car then instantly loses the ability to accelerate and you can push the pedal all the way down and it will not go faster. There is an issue with either the engine, the power train or the speed control, or some combination. The car will not go above 20 miles per hours. These instances have almost caused us to get rear-ended by other vehicles as we suddenly lose the ability to accelerate. It is extremely dangerous and we've been fortunate to be near off-ramps to get off. The problem has been confirmed by Mercedes Dealerships with friends of ours who have experienced the same problem with a different model. They claimed that Mercedes USA had not found a fix yet, but refused to provide us with a loaner car until this death trap of a car was fixed.

NHTSA ID

11594916

Incident

Oct 1, 2023

Date of occurrence: 03/05/2024 Subject: Formal Claim Regarding Traffic Safety Issue with 2021 Mercedes Benz CLA 250 I am writing to formally submit a claim regarding a recent traffic safety incident involving my 2021 Mercedes Benz CLA 250. While driving to my destination, I encountered a sudden loss of power and inability to accelerate. To ensure the safety of myself and other drivers, I activated my emergency lights and cautiously proceeded at a limited speed of approximately 30 mph, accompanied by a strained engine sound. Understanding the potential risks associated with this issue, I immediately pulled over in a safe location and had to drive the vehicle with caution to my home where I then arranged for my vehicle to be towed to the service department. Upon inspection, the service department informed me that the problem stemmed from a software malfunction, for which Mercedes has not yet released an updated version. Given the nature of this incident and the potential safety hazards it poses, I am deeply concerned about the safety of driving my vehicle on the freeway or to any destination. I kindly request your assistance in addressing this matter promptly and ensuring the necessary steps are taken to rectify the software malfunction. Please let me know the next steps in the claims process, any additional documentation or information required, and the estimated timeline for resolution. I appreciate your attention to this matter and look forward to a swift resolution. Thank you.

NHTSA ID

11575656

Incident

Feb 2, 2024

On Monday 02/14/2022, after 2-3 minutes driving towards work, at about 25-30mph speed, the front right ball joint broke on the vehicle putting me in danger of losing my life. Due to this ball joint failure, the right front wheel disassembled from the vehicle and it slid-crashed on the car parked on the right side of the street. If it would happen on the highway I would kill myself and put others in the ultimate danger of losing their lives. The car was towed to the Loeber Motors Dealer and Mercedes-Benz LLC. informed about the incident. The the complaint case number 2-25420239808 was started with Mercedes-Benz Customer Care and led by: Susan Executive Referral Manager Mercedes-Benz USA, LLC (800) 367-6372 (ext. 6324) This defect should never happen and again, it could be lethal, causing many deaths if with full speed on the highway. Case was completely ignored by Mercedes-Benz LLC. Now it is 03/20/2022 and I still don't have any report on the safety of the vehicle. Mercedes-Benz Dealer Loeber Motors, called me on Friday 03/18/2022 saying "that if I won't tow out the vehicle from their property they will charge me $100 per day for storage - about $3000" - that way they simply forced me to put my case in the hands of my insurance without giving me any word on my vehicle safety. Mentioned earlier Mercedes-Benz Representative - Executive Referral Manager Susan, was refusing to answer my calls and never sent me any reports regarding my case. I consider such failure to be extremely dangerous and the case very serious. There were no earlier signs of any problem. The only thing I could add, 2 days before that happened, I was backing up into the parking spot on the street and I drove over a quite high pile of icy snow. Manufacturer completely ignored the case. Thanks

NHTSA ID

11457479

Incident

Feb 14, 2022

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 CEL light on with no drivability concerns. Cause Signal timing error. Remedy 167, 465: SW has been released. Update the FSAM to the latest SW version. 290, 118, 243, 247: Software is still in development. This fault code does not cause a drivability concern and will clear itself within 2-3 key cycles. The vehicle can be released back to the customer.

Complaint Hand detection system – malfunction / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist not available" "Active Lane Keeping Assist not available" "Active steering assist not available" Cause Possible causes: Hand detection mat, hand detection control unit, contacts, and electrical feed line. Remedy In the event of a customer complaint and fault code in IDC control unit: U186B29 in IDC223 or fault code U0429E0, U042941, U042929, U042902, U0429E1 in IDC213 or fault code in HOSWD control unit: B1E7614 Check: Please do not replace the HOSWD control unit. Please flash the new SW and perform the SCN coding for the HOSWD control unit (N179/1) (available from July 2026). The software can be flashed onto all HOSWD213 with HW number A0009011522 and all HOSWD223 with HW number A0009011422. Please also flash the SW for the IDC control unit (N62/4), if possible (only applies to HOSWD223). Erase fault memory Remedy: Turn on the ignition or start the engine without touching the steering wheel. If, after 10 seconds without touching the steering wheel, one of the three fault messages appears on the instrument cluster: Check the contacts and feed lines in the steering wheel by means of a visual inspection for damage, crimp connections, loose connections, etc. (example in picture 2 and 3). If there is visible damage -> replace the steering wheel electronics or the feed lines. If there is not any visible damage -> replace the steering wheel rim. If a yellow message does not appear on the instrument cluster within 10 seconds: Grasp the steering wheel fully with both hands, including the chrome molding at the 6 o'clock position (see picture 1). If the fault is triggered by grasping the steering wheel rim or pressing the clip at the 6 o'clock position, check the contacts and feed lines in the steering wheel by means of a visual inspection for damage, kinked connections, loose connections, etc. (example in picture 2 and 3). Check the ground connections (screw connections and cables to the steering wheel rim); if necessary, retighten the screws/bolts and check for corrosion (picture 4). If there is visible damage -> replace the steering wheel electronics or the feed lines. If there is not any visible damage: Replace the steering wheel rim. Please do not replace the HOSWD control unit. A TIPS case should be created if fault profile is unclear. In the event of a customer complaint and a further fault code in HOSWD: B1E7713: Check the ground connections (screw connections and cables to the steering wheel rim); if necessary, retighten the screws/bolts and check for corrosion (picture 4). B1F1F04: Check the control unit of the hand detection system; if necessary, replace this with the control unit from a donor vehicle (make sure that the hardware part numbers are identical).

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 Radio station cover art does not refresh when switching stations. The UI continues to show the old station’s artwork instead of updating to the new one. Cause When a new station change request is triggered, a temporary glitch is causing the Head Unit application to fail to overwrite the previous request. This glitch is causing the cover art mismatch in the Radio application. Remedy Please do not replace any parts. The E505.9 software is released and available in XENTRY Q3 2026.

Complaint CEL light on with no drivability concerns. Cause Signal timing error. Remedy 167: SW has been released. Update the FSAM to the latest SW version. 465, 290, 118, 243, 247: Software is still in development. This fault code does not cause a drivability concern and will clear itself within 2-3 key cycles. The vehicle can be released back to the customer.