What 433 owners told NHTSA about the 2015 Mercedes-benz C-class Phev

Purchased this car in September 2024 for our [XXX] son. Upon inspection at our local Mercedes Dealership on December 1, 2025, we were informed that the rear subframe should be immediately replaced as there is a rusted hole in the subframe, "compromising the structural integrity of the rear of the vehicle." We were informed that the prior bulletin issued for 2010-2014 C-Class models did not include our 2015 C-Class. We were quoted over $5200 to repair the subframe. There were no warning messages, lights problems that were noted, prior to inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11708959

Fuel hose system leaking. Inhalation of gas fumes caused headaches and nausea. Risk of vehicle fire. Yes, the problem has been confirmed by a Mercedes dealer. This is a known issue with Mercedes C300 2015 models and other years. There have been other complaints/lawsuits against Mercedes not wanting to pay for the issue. No warnings just strong gas smell.

NHTSA ODI 11707032

I took my car for service and they found a rusted rear subframe, with a small hole in it. I was informed that the car was not safe for my annual trip from NJ to FL (about 1000 miles). I was also told that this defect was a recall for cars through 2014. My car is a 2015 and I have the same defective part - which is supposed to be manufactured with rustproof material. I am requesting that this car be recalled and the part replaced by the manufacturer.

NHTSA ODI 11702655

The car suddenly glitched and locked itself—with my dog, my purse, my phone, everything—inside on an extremely hot day. There was no one around, and it was terrifying. I had opened the passenger door for my dog to climb in, and as I walked around to the driver’s side, the doors somehow locked on their own. Panic set in immediately. My dog, my phone, and my purse were all inside, and I had no way to call for help. We had just finished a walk, and then this happened out of nowhere. I had to run around searching for someone who could help. Eventually, I found a stranger who called the police, and they had to break the door open because it was over 100 degrees outside. I was terrified my dog would pass out from the heat. There were no warnings, no alerts, no messages. If it weren’t for that random stranger who happened to be there and willing to help, I don’t know how I would have gotten my dog out. It’s a reminder of the kindness of strangers, but the glitching car was truly terrifying and not ok.

NHTSA ODI 11702391

My car’s rear subframe was so badly disintegrated due to severe corrosion. It made the driving so dangerous when braking and nearly caused an head-on collision. I have reported this issue under tracking number 11701609 and would like to provide pictures on the corrosion issue.

NHTSA ODI 11701834

My wife first noticed loud noise from the back of the car when braking. Subsequently, when I drove it one day after, the car lost balance and nearly went into the opposite direction of the road on a two-lane street. The MB dealership later confirmed the problem was a severely corroded rear subframe that needs to be repaired at very significant expense. This is a serious safety issue that could have caused a head-on collision for me and my wife as a passenger on that occasion. I believe this issue warrants a full investigation by the NHTSA. I understand other Mercedes models such as the 2008-2015 C300 (W204) had the same corrosion issue and was under a recall but my car model (W205) was not covered by this recall. Thank you for your attention to this matter. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11701609

Rear subframe rusted out, car is not safe to drive

NHTSA ODI 11698179

Rear subframe completely rusted out. While driving on the hwy I heard a loud noise, a couple minutes later I hit the brakes to slow down to get off my exit and after pressing the brakes the car instantly fishtailed sending me sideways across 2 lanes of traffic. Luckily no one was injured or killed. I’ve seen that the car manufacturer was replacing this issue on models 2008-2015. My vehicle is a 2015 and they are telling me my vehicle is not covered for the issue. The car is not drivable and Mercedes needs to be held accountable. A critical component such as rear subframe completely rusting out in just under 10 years is unheard of and I can’t afford to pay 10k to fix it. Please help

NHTSA ODI 11696650

I’m the owner of a Mercedes Benz C- Class Sedan 2015. My Rear Sub Frame Rusted Through at The right trailing arm - Fails state inspection. Mercedes Benz has issued a extended 20 year warranty on all vehicles from 2008 - 2015 C - Class Sedan for Rear Sub Frame that rusted out. Mercedes Benz service advisor stated that my vehicle was not under that extended warranty when he run my vehicle Vin number. My vehicle should be under that warranty, I have the same problem with the same vehicles on the list. Please help. Thank you

NHTSA ODI 11695279

The Rear Subframe on this vehicle is rusted and has hole in it. The sub frame requires replacement. The sub frame was inspected by the Mercedes-Benz Dealership, Euro Motorcars in Germantown, MD and they recommended that the sub frame should be replaced. There is an extended warranty that has been issued by Mercedes-Benz for the Model Year and Model (2008-2015 C-Class Sedan/Coupe). However, Mercedes-Benz decline to cover the cost of the repair stating that my VIN is not part of that Warranty. This is a well documented safety issue and I believe that Mercedes-Benz should include my VIN in that extended warranty and replaced the subframe on my car.

NHTSA ODI 11688397

I took my 2015 vehicle to the Mercedes dealership and learned the rear subframe is rusted and has holes on two sides. I was warned that it is a safety hazard and could lead to a lack of control and other dangerous situations. I also learned that other 2010 through 2014 Mercedes models in the same class have been recalled for this exact concern. I am disappointed and upset to learn that those concerns are known, but not addressed in this model and put customers at risk.

NHTSA ODI 11687651

there is a recall for 2008-2015 Mercades Benz c-300 c/w204. this recall talks about the rear subframe rusting out early on this car. we have a 2015 c300 c/w205. this car is seeing the same early rust seen in the other c-300. the dealership is refusing to do right by the warranty because it is a c/w205 even thought this is a known problem for this year and type of car. I am making this because it should be extended to all c300 2008-2015 cause they all use the same subframe. they changed the subframes and the look of the c-300 starting in 2016. it also would appear that the rust is coming from the inside of the subframe making we wonder how bad it is on the inside if it is making its way to the outside of it. I believe water penetrates into the rear subframe has no drainage and begins to rust. also we take the car to the dealer every 5 Ish months and this last service is the first we have seen of this.

NHTSA ODI 11687391

The contact owns a 2015 Mercedes-Benz C300. The contact stated that upon taking the vehicle for the State Inspection, the contact was informed that the rear subframe was rusted, and there was a hole on each side of the rear subframe. The vehicle was taken to the dealer, where an unknown diagnosis was made, and the dealer ordered an unknown part to repair the vehicle. The vehicle was not repaired. The manufacturer was notified of the failure but denied assistance. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 60,000.

NHTSA ODI 11681594

The contact owns a 2015 Mercedes Benz C400. The contact stated that while vehicle was inside a high-pressure car wash, water leaked from the roof panel at the front of the vehicle, nearby the front windshield. The cause of the failure was not yet determined, and the vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact was informed that the VIN was not included in the NHTSA Campaign Number: 23V854000 (STRUCTURE). The contact stated that the vehicle had experienced the failure listed in the recall. The local dealer was not contacted. The failure mileage was 100,000.

NHTSA ODI 11679248

The contact owns a 2015 Mercedes-Benz C300. The contact stated while driving 40 MPH, the vehicle unexpectedly veered to the left. There was no warning light illuminated. The contact stated that the steering wheel became inoperable, and the contact was unable to straighten the steering wheel. The brake pedal was also depressed. The contact attempted to depress the accelerator pedal however, the vehicle started to stall. The contact pulled over into a parking lot and was able to restart the vehicle. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 82,000.

NHTSA ODI 11678756

On January 21,2025, I had an appointment for an inspection at Mercedes Benz of Smithtown, the dealership I use. I was informed that my car required replacement of a rotted rear subframe. A hole had rotted through, causing the car to "Fail inspection and was NOT SAFE" to drive. I was provided a video showing the damage. There was a recall in effect however, my Vin # was not included and it’s status has not changed. The 2015 C-Class Sedan/Coupe Vin # [XXX] , which was neglected to be included in the recall covers 2008-2015 C-Class Sedan/Coupes, regarding rotted rear subframe. MBUSA extended the vehicle Warranty 4 yrs/ 50,000 miles to 20 yrs/unlimited miles. However, I do not qualify for reimbursement of $4,014.92, because my Vin # was left off the list. Mercedes customer assistant center states they can't help, has to be included by NHTSA, when I said they cannot add a Vin #. I was then told, it has to come from the head office in Germany. Nothing like getting a run around not what I expected from Mercedes Benz USA, INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11675408

Failed component: Front Sunroof Clip What component or system failed or malfunctioned, and is it available for inspection upon request? Sunroof clip, yes. How was your safety or the safety of others put at risk? The glass pane lifted while the car was in motion and had to be held down to secure it until the car stopped. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? No Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No While merging to enter the freeway at approx 45-50 mph I opened my sunroof. At about halfway back the glass began to lift up off the track/railing as if it was going to fly off the track. Had I not been holding the button to open the sunroof I would not have noticed and the entire glass pane would have blown off, possibly damaging the car or worse flying off and hit another car. I had to hold the glass in place to keep it from flying off until I was able to exit the freeway. Once I stopped the car to inspect the sun roof I noticed the clip that secures the glass to the track was broken (crumbled) in the sunroof track. I removed the pieces of broken plastic from the track and was then able to close the sunroof. I am now unable to safely open my sunroof while the vehicle is in motion.

NHTSA ODI 11672076

The contact owns a 2015 Mercedes-Benz C300. The contact stated that upon taking the vehicle to an independent mechanic for a routine maintenance check, the contact was informed that there was severe corrosion on the subframe of the vehicle. The contact was informed that the vehicle was unsafe to drive and that several failures might occur due to the failure. The contact stated that recently, while depressing the brake pedal, the vehicle swerved, and the contact lost control of the vehicle. Upon investigation, the contact discovered that there was a warranty on the vehicle related to the failure. The manufacturer was notified of the failure, and the contact was informed that the vehicle was no longer covered under the warranty. The vehicle was not repaired. The failure mileage was approximately 110,000.

NHTSA ODI 11671701

Check Engine light came on recently, fault code P052E is identified by scanner. Car has 60,000 miles on original it. MB dealer wants to charge $300 for diagnostics, repair job (parts and labor) may cost over $2,000. Since this is critical emission compliance part/system, why is it not recalling?

NHTSA ODI 11669468

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while his wife was driving at an undisclosed speed, the roof panel detached from the vehicle and fractured. The contact stated that the roof panel had previously been replaced, but the failure occurred. The vehicle was taken to the dealer, where it was determined that the front roof panel needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The manufacturer was made aware of the failure. The failure mileage was approximately 70,000.

NHTSA ODI 11669469

Panoramic glass sliding plastic brackets broke off while driving at 25-35 mph Lifting up the glass off the vehicle. Quick reaction saved the large detached glass from flying off into the roadway injuring or killing someone. Vehicle was 5 years old and out of warranty. Dealer estimated repair cost at $2500

NHTSA ODI 11665351

On May 27th, 2025, during highway driving suddenly the sunroof got open by itself for like 3 inches upwards from the front and after exiting the highway i stopped and push the sunroof downwards by applying the force and apply duct tape all around the sunroof to keep it protect from sun and rain so i am not driving anymore before getting it resolved.

NHTSA ODI 11664393

Rear-subframe corrosion at the lower-control-arm mounts has progressed to the point where both arms have play and produce loud metallic bangs while braking or turning at low speed. Two independent shops lifted the car, documented flaking rust around the bushing sleeves, and advised the subframe is structurally compromised and could let a control arm detach under load. The corroded subframe remains installed and can be inspected on request. Safety risk: a detached rear control arm would cause sudden, unpredictable steering and loss of control. The vehicle already pulls right under braking, and feels very unstable in curves Problem has been reproduced and photographed by two independent repair facilities. No manufacturer representative has inspected the vehicle so far. Additional component failures possibly linked to the same progressive chassis stress: premature wear of both front CV axles; timing-chain stretch with worn guides; slack oil-pump chain; upper & lower oil-pan gasket leaks; water-pump seepage; right engine-mount collapse; persistent misfire traced to a loose intake-hose clamp; transmission-cooler hose clip released under pressure, dumping all ATF and destroying the automatic transmission; excessive play in all four lower control-arm bushings. The transmission and the other components were replaced 1-2 months before the subframe bro History: A faint clank from the rear suspension first appeared roughly three years into ownership. Dealer service dismissed it as “normal noise,” and warranty would not cover “loud clanks,” so the issue went unaddressed. The noise has grown steadily into the current condition, suggesting long-term subframe corrosion that was never inspected or remediated. No collision, flood, or off-road use; the car has typical Northeast winter-salt exposure. The failure pattern matches subframe-corrosion cases already acknowledged by the manufacturer on this model, although this serial number is not yet included in the official campaign.

NHTSA ODI 11663816

Structure,Body.Roof & Pillars

NHTSA ODI 11663519

Power steering malfunction Car unable to drive I believe there is supposed to be a recall for this issue but not popping up when I put in VIN number Warning lamps come up. Sometimes every light on dashboard. Took it to Mercedes but it was when code was not popping up and they said I needed a new battery. Did that but still an issue. Has also happened when driving. Sometimes collision assist plus light comes on and power steering acts up. Light I am pointing at in picture is another light that consistently pops up I have been able to intermittently fix problem by resetting computer by unplugging battery for 15min or longer. As well as confirming full service on vehicle. Now it isn’t working though.

NHTSA ODI 11660262