What 251 owners told NHTSA about the 2017 Mercedes-benz C-class Phev

The contact owns a 2017 Mercedes-Benz C300. While driving at approximately 15 mph, the contact observed smoke emanating from under the hood. The vehicle was driven to her work location and parked. Upon exiting the vehicle and opening the hood, she observed orange flames coming from the engine compartment. A parking attendant extinguished the fire, and a police and/or fire report was filed. The vehicle was towed to a dealer and diagnosed with a fuel line leak that caused the engine harness to come apart. The leaking fuel hose from the high-pressure fuel pump caused damage to the high-pressure pump, engine harness, vacuum transducer, and coolant feed line from the thermostat to the firewall. The following components needed replacement: high-pressure fuel pump, rubber fuel hose, engine harness, pressure transducer, and intake manifold. The vehicle was repaired. Five months later, the contact experienced another failure she believes was associated with the engine fire. While parked and attempting to start the vehicle, it did not start. The vehicle was towed to a dealer and diagnosed with a faulty starter that needed replacement. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 65,422.

NHTSA ODI 11738037

strong evident fuel/ gas smell when driving and when the car is in park after driving.

NHTSA ODI 11735746

Check engine light for P052E which has been coming and going off for years now. Now the check engine light is there permanently. I spoke to Mercedes Benz customer service and requested for them to fix the problem now that the light is on permanently but they refuse to fix it because the car has 222,000 miles on it. This should be a recall from the manufacturer not an extended warranty coverage. The Mercedes dealer in Valencia California told me they now only do a software update and put a plug cap on the sensor and want to charge me $850 even though this should be a recall

NHTSA ODI 11725960

UNKNOWN it was just one day I started my car and turned the A/C on and I started getting this strong gasoline smell. I went on like a saw there is a recall for this problem for the M274 engines.

NHTSA ODI 11708103

While driving home from work, without any warning or blunt force the sunroof exploded and shattered glass was everywhere

NHTSA ODI 11705275

any action on Case 11699173 ?

NHTSA ODI 11702507

Case already called in 11699173 - Stuck Seatbelt in B Pillar of 2017 Mercedes Benz 2 door hard top coupe. Seat belt will not come out of A pillar rendering seatbelt totally inoperable This VIN comes up negative under recall 21V03200 Case filed with MBUSA 18991593 still unresolved. Dealership is claiming a 2,200 Seatbelt Assembly is needed. now warning lights. The seatbelt was " lazy " and didn't smoothly retract prior to this incident when parked, door closed, the belt retracted with a loud motorized noise and now will not retract at all from A Pillar - Please follow up with on this Case # already called in over a week ago

NHTSA ODI 11701042

The contact owns a 2017 Mercedes-Benz C300. The contact stated that upon arriving at his destination and exiting the vehicle, the driver’s side seat belt retracted and became stuck in the retracted position. As a result, the contact was unable to use the driver's side seat belt. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the seat belt assembly. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 21V032000 (Seat Belts), but the VIN was not included. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 67,000.

NHTSA ODI 11699173

Cabin smells heavily like fuel and has a check engine light possibly a fuel leak

NHTSA ODI 11698322

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving 65 MPH on the highway, the contact heard a popping sound coming from an unknown part of the vehicle. The contact pulled over to the side of the road, exited the vehicle, and became aware that the roof panel had shuddered. The contact stated there was no glass in the vehicle. No injuries were sustained. The contact stated that the failure had occurred on two occasions. The vehicle was not taken to an independent mechanic or the dealer to be diagnosed. The vehicle was taken to the dealer by the previous owner to be repaired under NHTSA Campaign Number: 21V197000 (STRUCTURE); however, the recall repair failed to prevent the failure. The manufacturer was notified of the failure and informed the contact that there was no recall related to the failure. The manufacturer offered the contact a trade for the vehicle. The failure mileage was 105,000.

NHTSA ODI 11697621

I am reporting a serious vehicle safety hazard caused by improper and unsafe repair work performed by USA Platinum Motor, located at 1221 California Lane #126B, Arlington, TX. I brought my 2017 Mercedes-Benz C300 in for a cold start rattle with no warning lights or prior issues. The shop diagnosed a loose timing chain and I authorized the repair. After the repairs, the vehicle was returned with critical safety defects, including a loose fuel pump, unsecured fuel line, missing bolts, and improperly reassembled engine components. Shortly after pickup, the car experienced loss of acceleration on the interstate, a strong odor of fuel, and a sudden loss of power, creating a dangerous and life-threatening situation. The vehicle had to be towed back to the shop. The manager, who is not a certified mechanic, admitted he personally “fixed” the issue by tightening the fuel pump himself. A Mercedes-Benz diagnostic inspection later confirmed multiple severe assembly errors, including missing fasteners, unsecured oil cooler, disconnected vent lines, and other safety-related defects in the fuel and cooling systems. These unsafe and negligent repairs created an extreme fire hazard, engine instability, and risk of sudden failure while driving. I am requesting a formal NHTSA investigation into this matter to ensure vehicle safety compliance and to prevent similar incidents affecting other consumers.

NHTSA ODI 11696497

This is the same as recall for NHTSA ID: 21V-197. The panel flew off my 2017 Mercedes C300 W205. My vin number is not included in the recall. This is a safety issue and will need to be replaced.

NHTSA ODI 11695341

See attached document for complaint.

NHTSA ODI 11693851

Sunroof detachment Sunroof fell off while driving

NHTSA ODI 11693928

Sunroof Front Trim for Mercedes-Benz GLC300 IS ALL SCRATCHED BUT MERCEDES BENZ SAYS IT IS NOT COVERED BY THEM.

NHTSA ODI 11690472

The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving at 60 MPH, the contact became aware that an unknown part had detached from the vehicle. The contact stated that after stopping to refuel the vehicle, it was discovered that the roof panel was missing. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact related the failure to NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.

NHTSA ODI 11681330

The sunroof exploded spontaneously while driving to a destination. When the incident happened, I was stopped at a red light. I panicked as it sounded like gunshots hitting my car. I pulled over to the nearest safest destination to inspect the car. This put the safety of myself at risk and others at risk who were driving along the sides and/or behind me. This incident was confirmed by a dealer, as I went to Mercedes Benz Sugar Land on the following day of the incident and was quoted around $3,700 to have it repaired. The vehicle not been inspected by police and/or insurance. There were no warning signs that this could have happened besides the fact that Mercedes Benz USA is currently under an active lawsuit for this happening to several other drivers. I do believe that this is a manufacturing defect affecting safety, as similar incidents involving Mercedes-Benz panoramic sunroofs, which may indicate a wider defect trend.

NHTSA ODI 11680437

In October 2024, the rear subframe was replaced due to rust perforation in the area of the suspension arm mounting bracket. I had no warning. The car was in for routine service at Mercedes Benz of New London. It had rusted from the inside out and was considered unsafe to drive by the Mercedes service advisor. I could have had a serious accident! I had no choice but to replace the subframe as it is my only vehicle. Shockingly I learned many others have had this issue with various Mercedes models/years and that Mercedes Benz knows of this serious safety problem and there is a class action lawsuit pending but subframe replacement is not covered under warranty by Mercedes Benz, so the cost was mine to bear.

NHTSA ODI 11676702

My car caught on fire due to AC malfunction

NHTSA ODI 11674814

The contact owns a 2017 Mercedes-Benz C300. The contact stated that both the front driver’s side seat belt and front passenger's side seat belt had failed to retract as needed. There was no warning light illuminated. Additionally, the contact stated that the seat belts buckles would unintendedly lodge under the seats. The vehicle was taken to the local dealer, but was not diagnosed or repaired. The contact related the failure to NHTSA Campaign Number: 21V032000(Seat Belts); however, the VIN was not included. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was unknown. 

NHTSA ODI 11666563

The sunroof is very glitchy and this is common in all Benz I have had a few different Benz and they all eventually have this same issue with their panoramic sunroof. Sometimes it opens half way life one side is up and the other side is closed and other times it will open fully but not close and other times it won’t open at all. This is a common problem that many Benz owners have stated this in the Benz forums all over. This is a safety issue due to unexpected weather conditions if it rains and it’s stuck inside gets damage and owners get wet which is also a distraction and may cause accidents. Please investigate this issue thoroughly. Their sunroofs should be recalled and extended warranties placed on them automatically by Mercedes Benz due to this being a very common issue in all model’s panorama sunroofs particularly C300s year 2017 thank you for looking into this matter.

NHTSA ODI 11665836

unknown

NHTSA ODI 11656486

ESP control unit software Recall 2016090002 Recall 2017110002 Recall 2020080016 And my car shows there’s cero recall active but is giving me problem showing code: U0121 u1110 U0122 B227d U0423 B227d

NHTSA ODI 11654348

this is my send time writing in. mercedes used the wrong wrist pins for the pistons leading to my wife getting a cracked piston on freeway in phx.if you look up cylinder 1 issues on this model there is a lot of people who have encountered this. why this hasn't been recalled and sticking consumers with a10k plus repair is beyond me. if you use the wrong parts you should be responsible for the repair!!!

NHTSA ODI 11643047

Error code P052E71 on a 2017 c300 with 100k miles. It seems to be a very common and recurring issue that appears to have no real solution and is costing consumers thousands upon thousands. This malfunction does relate to emissions and this vehicle is operated in California.

NHTSA ODI 11635619