MERCEDES-BENZ Complaints

CEL followed by no crank / no start. Codes u3017 and u0168. Software flashed and no crank / no start returned. SAM & EIS modules replaced and no crank/no start returned with new codes. U103F00 + P143400 + P051300. Now Mercedes is directing the replacement of the ethernet harness between the SAM and EIS. This intermittent communication or electrical fault can cause the vehicle to unexpectedly lose the ability to start. This creates a safety concern because the vehicle could fail to restart after being stopped in traffic, at an intersection, at a fuel station, or in another location where reliable starting is necessary. The intermittent nature of the failure also makes it difficult to predict when it will occur. The vehicle has sometimes operated normally for extended periods and then unexpectedly failed to start. As of filing this report the issue remains unresolved.

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.

Vehicle would unexpectedly stall out while driving at slow speeds or stopped. Car was brought to an independent car shop and it was determined the Fuel pump had started to come apart sending debris into the fuel tank/system causing low fuel pressure. The fuel tank with fuel level sensor and suction jet pump was replaced along with, fuel injectors and other fuel system components. This looks very similar to other Mercedes Fuel system recalls that does not seem to cover the GLA250 but has the same manufacturer parts. NHTSA campaign numbers 23V880 and 23V881 represent a massive safety recall issued by Mercedes-Benz USA due to a defective fuel pump The problem: A component inside the fuel pump was made from faulty materials and may fail prematurely. If this happens, the vehicle’s engine may shut off while driving, and the car may lose power.

BATTER RECALL FIRE SAFETY: I have a 2023 Mercedes-Benz EQB 250+ affected by NHTSA safety recall 26V073. Mercedes has acknowledged that the high-voltage battery can fail internally and cause a fire. I’m instructed to charge only to 80% and park outside away from structures, and Mercedes’ latest remedy requires replacement of the entire high-voltage battery. This is already a low range vehicle and limiting to max 140 miles on interstate before having to charge 45 minutes is a nightmare. I need to drive between states for work and this is just simply not feasible after doing so for months without a solution. The first recall was March 2025 with no fix.

My 2016 Mercedes-Benz CLA 250 has a check engine light for code P052E, which points to a broken crankcase ventilation valve. My car has only 59,000 miles on it, but this same exact part already broke once before and was replaced under the original warranty. Now, the replacement part has failed too. This proves the part is defective and keeps breaking. Mercedes-Benz already knows this part is defective. They gave a free 15-year or 150,000-mile extended warranty to fix this exact issue for free on the C-Class and other longitudinal M274 engine platforms. However, they are actively denying coverage for my CLA 250's M270 engine variant, despite the two vehicles sharing nearly identical engine blocks, matching subcomponents, and the exact same broken part. Because of this unfair engine code technicality, Mercedes-Benz is forcing CLA owners to pay thousands of dollars out of pocket for a recurring problem they fix for free on a C-Class. I urge the NHTSA to look into this engine loophole and force Mercedes-Benz to include the M270 engine variants under the 15-year/150,000-mile free repair program.

My 2016 Mercedes-Benz CLA 250 (VIN: [XXX]) has a check engine light for code P052E, which points to a broken crankcase ventilation valve. My car has only 59,000 miles on it, but this same exact part already broke once before and was replaced under the original warranty. Now, the replacement part has failed too. This proves the part is defective and keeps breaking. Mercedes-Benz already knows this part is defective. They gave a free 15-year or 150,000-mile extended warranty to fix this exact issue for free on the C-Class and other longitudinal M274 engine platforms. However, they are actively denying coverage for my CLA 250's M270 engine variant, despite the two vehicles sharing nearly identical engine blocks, matching subcomponents, and the exact same broken part. Because of this unfair engine code technicality, Mercedes-Benz is forcing CLA owners to pay thousands of dollars out of pocket for a recurring problem they fix for free on a C-Class. I urge the NHTSA to look into this engine loophole and force Mercedes-Benz to include the M270 engine variants under the 15-year/150,000-mile free repair program. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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.

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.

The contact owns a 2019 Mercedes-Benz A220. The contact stated that while the vehicle was parked, the front driver's door failed to latch as intended. The dealer was notified of the failure, but no assistance was provided. The vehicle was not diagnosed or repaired. The contact received notification of NHTSA Campaign Number: 26V481000 (Latches/Locks/Linkages); however, the part to perform the recall repair was not yet available. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was approximately 77,000.

I am a mechanic speaking on the behalf of a customer; this customer is experiencing problems with her rear subframe. The older generation of her car has a famous issue with rear subframe rusting out. Her car uses an updated part number that is almost identical in construction to the failure prone part that was famous for rusting out, although they are NOT the same number. The failure prone number is 2123503805 or 2043500141, they are installed on the older chassis, w204, w212, etc. The part that is in THIS vehicle is 2123503605, the construction is almost identical to the part numbers listed for the w212 and w204 provided above. There is no drainage holes provided for water that has entered through rain or any other detritus that will permeate on the road's surfaces through natural progression of the vehicle's life, like on the older chassis. The material used is steel with paint on the outside instead of some sort of encapsulation that coats both inside and outside surfaces. And because these don't have any sort of ability to evacuate any substances, they are interacting with unprotected metal and will react into rust. This failure can lead to misalignment at the very minimum of problems, at the worst, it can cause control arms falling off, causing wheel hub assemblies to fall off, this shouldn't have to be explained but this can cause major injury or death, not only to the passengers to the vehicle, but to others who share the misfortune of being at the wrong place at the wrong time. And, the understanding of these not being the SAME part shouldn't warrant the extension of the recall to these particular vehicles, but the failures are similar to what was seen before on other older vehicles and should warrant further investigation. With hope, this could just be an isolated incident, but since patterns are uncanny, this should be investigated with some interest to the public wellbeing. Cordially Naseam F. Samaan Licensed Virginia State Inspector. Sanko Auto Care