2009 Mercedes-Benz C 300 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2009 Mercedes-Benz C 300, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Electrical19824.7%
- Airbags18222.7%
- Steering13616.9%
- Exterior lighting11814.7%
- Suspension364.5%
- Driver assistance273.4%
- Body & structure273.4%
- Engine222.7%
- Brakes212.6%
- Tires & wheels91.1%
- Seat belts91.1%
- Fuel system50.6%
- Other / unspecified50.6%
- Powertrain (other)50.6%
- Interior & seats30.4%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
I have messages on my instrument panel stating I have airbag malfunction going on I also have tail lights that are not working and after trying to replace the bulbs it still don't work so obviously it's the light bulb panel so I went and looked at recalls and says that these are all recalls on my car but that they were fixed. so I don't know why I have them all bad again so I need to know what to do
The contact owns a 2009 Mercedes-Benz C300. The contact stated that while starting the vehicle, the check engine, seat belt, and air bag warning lights illuminated. Additionally, the headlights and navigation lights failed to activate for a while. There was burning odor inside the vehicle with the heat activated or turned off. The contact also stated the vehicle failed to start for three days before eventually being able to start. The contact attempted to charge the battery, which resulted in a visible spark. The vehicle was taken to a dealer where it was diagnosed with a sound module and the Signal Acquisition Module (SAM) failures. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 217,000.
Airbags
Reports naming the air-bag system — deployment behaviour, inflators, sensors and warning lights.
From owner reports, verbatim
I have messages on my instrument panel stating I have airbag malfunction going on I also have tail lights that are not working and after trying to replace the bulbs it still don't work so obviously it's the light bulb panel so I went and looked at recalls and says that these are all recalls on my car but that they were fixed. so I don't know why I have them all bad again so I need to know what to do
The contact owns a 2009 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the "SRS System Requires Service" was displayed. The air bag and check engine warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the vapor canister shutoff valve but had not provided a diagnosis for the SRS system. The vehicle was repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 99,000.
Steering
Reports naming the steering system — racks, columns, power-steering assist and steering linkage.
From owner reports, verbatim
The problem is that the steering wheel locking mechanism has failed. The vehicle could not be started or driven. It required a flatbed tow to an authorized Mercedes repair facility. It was diagnosed as the steering mechanism, requiring replacement. The cost for this repair is $1400.00. I researched this problem on the MB website and it stated that this issue was common. I feel that this is a safety issue and should be repaired free of charge or at a significant discount. The car is currently being repaired, and I can forward any relevant documentation to you once the repair is complete.
I drove my car to get lunch. Came back out to go back to work and the car would not start. Would not even turn over. My Radio did not turn on and I couldn't even roll my windows back up. Luckily they were only cracked open a small amount. My steering wheel cannot be turned, it's locked in it's current position. I am told the ESL (Electronic Steering Lock) and possibly the EIS is the cause of this problem. The display on the dash says "Take your key from ignition" and that is all I get. Had to have my car towed and now I have a dead car with the windows partially open that I cannot close.
Exterior lighting
Reports naming headlights, tail lights, turn signals and other exterior lighting.
From owner reports, verbatim
I have messages on my instrument panel stating I have airbag malfunction going on I also have tail lights that are not working and after trying to replace the bulbs it still don't work so obviously it's the light bulb panel so I went and looked at recalls and says that these are all recalls on my car but that they were fixed. so I don't know why I have them all bad again so I need to know what to do
Check Right Tail and Brake Lamps warning light will not go off for months. They are working fine but the light won't go off. Googling on MB World, it shows Mercedes is aware of this problem and a recall is needed to get it corrected being safety issue with warning lights not working properly. See all info. below from owners, conversations and work done by dealers, etc. People note it is a middle school education problem. Please alert me when the recall is confirmed to get this important problem fixed. [XXX] Thank you, [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Suspension
Reports naming suspension components — springs, struts, shocks, control arms and related hardware.
From owner reports, verbatim
The entire rear subframe of any W205 body model including but not limited to the C class from 2009-2014, CL class, SL, class ETC. suffers admittedly from MB USA, premature rust, deterioration etc. there is an active recall for these same models in Canada and all of Europe but not the USA. My garage kept 2009 C300 has suffered extensive rear end damage from a factory defect that Mercedes refuses to recognize in the Continental U.S. but will admit the same issues occurred in the EU and Canada. Keeler Mercedes, USA, of Colonie New York, stated they completed my subframe repair under the MB rear subframe extended warranty. The vehicle was driven home and inspected only to find out Keeler Mercedes of NY did NOT replace this crucial safety component under MB-USA extended warranty issued for this defect. This is pure negligence. When asked why the subframe wasn’t replaced as the work order stated it did, they stated “a mix up in paper work” I believe Mercedes-Benz USA and Keeler Mercedes of New York conspired together to push this massive safety defect aside and lie about completing the work in fear of the payment from warranty not being worth the labor hours required by the technicians. This oversight COULD have been a multi million dollar lawsuit if any injury was sustained after said repairs were done in belief the vehicle was safe to drive. Keeler Mercedes’ has also had this vehicle in their possession from June 14th 2024, to todays date, July 5th 2024 with no word on when repairs to subframe will be completed. Subframe replacement stated on MB website states it is an 8 hour labor job. We’re on day 18 now. MAJOR safety issue and shady dealing by dealership
After noticing brake fluid leaking I took my car to a local automotive shop and when he raised it to checkout the break line when he found the leak from the rust . he noticed a more serious problem that the subframe was rusted out on each side. He told me to contact Mercedes immediately because the car is unsafe to drive.
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
The contact owns a 2009 Mercedes-Benz C300. The contact stated that the coolant warning light was frequently illuminated due to low coolant. The vehicle was taken to an independent mechanic where the engine hose and other engine parts were replaced. Despite the repair, the coolant light returned soon after the initial repair. The contact then took the vehicle to a dealer where the failure was linked to NHTSA Campaign Number: 22V168000 (Exterior Lighting, Electronic Stability Control, Engine and Engine Cooling); however, the VIN was not included in the recall. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was unknown.
The contact owns a 2009 Mercedes-Benz C300. The contact stated while driving approximately 65 MPH, the instrument cluster started flickering and the vehicle stalled. The contact stated that the power steering and brakes were operable. The contact pulled off the highway and shifted the vehicle into park(P). The vehicle failed to restart and was towed to the dealer. The vehicle was not yet diagnosed or repaired. The manufacturer had been informed of the failure. The contact researched online and related the failure to NHTSA Campaign Number: 22V168000 (Exterior Lighting, Electronic Stability Control, Engine and Engine Cooling) however, the VIN was not included. The failure mileage was approximately 119,000.
Body & structure
Reports naming the vehicle structure, frame, body panels, doors, hood and trim.
From owner reports, verbatim
Vehicle inspection by independent service center indicated that a new rear frame was necessary. This was the second communication to nhtsa on this issue. This automobile (2009 c300) is inoperable due to this Mercedes rear frame defect .
The contact owns a 2009 Mercedes-Benz C300. The contact stated that while driving at various speeds, the rear end of the vehicle would fishtail and become extremely unstable while driving over a bump in the road or while turning. Upon inspection, the contact discovered that the subframe was severely rusted. The cause of the failure was not determined, and the vehicle was not yet repaired. The local dealer was notified of the failure. The manufacturer was not contacted. The failure mileage was 201,000.
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
The contact owns a 2009 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, the "SRS System Requires Service" was displayed. The air bag and check engine warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the vapor canister shutoff valve but had not provided a diagnosis for the SRS system. The vehicle was repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 99,000.
The contact owns a 2009 Mercedes-Benz C300. The contact stated while driving at an undisclosed speed, she became aware that the coolant level was low. The contact added coolant to the reservoir. The contact stated that the coolant reservoir burst open. The vehicle was towed to an independent mechanic who replaced the coolant and hose. The vehicle was taken to the local dealer but was not diagnosed or repaired. The vehicle was repaired, but the failure recurred. Additionally, the indicator lights became inoperable. The check engine warning light was illuminated. The contact stated the failure was associated with NHTSA Campaign Number: 22V168000 (Exterior Lighting, Electronic Stability Control, Engine and Engine Cooling). The manufacturer was contacted, but no assistance was provided. The failure mileage was unknown.
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
Went to the Mercedes dealership service department to replace the rear subframe that suddenly broke while I was driving due to extreme rust/corrosion. The dealership stated that it was being covered under the extended warranty due to the recall related to the rust/corrosion issue with the subframe. I was advised by the mechanic that the brake lines will need to be replaced due to extreme rust/corrosion in the rear at the same exact location of the rear subframe, making the vehicle very dangerous to drive because the brake lines could break at any moment and cause sudden brake failure. I was quoted a very significant amount to replace the rusted brake lines and per the dealership, it will not be covered under any extended warranty and/or recall.
The contact owns a 2009 Mercedes-Benz C300. The contact stated while driving and activating the turn signals, the taillights were inoperable. Additionally, the contact stated while driving and depressing the brake pedal to come to a stop, the brake lights were significantly dimmed except for the third brake light. The vehicle was taken to the dealer, where it was diagnosed with electrical failure. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 14V177000 (Exterior Lighting); however, the VIN was not included. The manufacturer was notified of the failure and informed the contact that they could not assist because the VIN was not included in the recall. The manufacturer referred the contact to the NHTSA Hotline for assistance. The failure mileage was unknown.
Tires & wheels
Reports naming tires, wheels, hubs, or the tire-pressure monitoring system.
From owner reports, verbatim
GOODYEAR ASSURANCE COMFORTRED 225/45R17 DEFECTIVE. SEVERAL CRACKS ON SIDEWALL OF ALL 4 TIRES. FRONT TIRES WITH 16,458 MILES AND REAR TIRES AT 25,000 MILES. LF TREAD 8/32 RF 9/32. REAR: 6/32 AND 8/32. I FORWARDED PICTURES TO GOODYEAR AND FILED A COMPLAINT 11/30/2018
TL*THE CONTACT OWNS A 2009 MERCEDES BENZ C300 EQUIPPED WITH COOPER TIRES, TIRE LINE: VELOZZA ZXV, AND TIRE SIZE: 255/35/R18 (N/A). THE CONTACT STATED THAT WHILE DRIVING AT APPROXIMATELY 70 MPH, THE TIRE PRESSURE WARNING LIGHT ILLUMINATED. THE CONTACT DISCOVERED THAT THE REAR DRIVER SIDE TIRE WAS FLAT AND THE TREAD SEPARATED FROM THE TIRE. THE VEHICLE WAS TAKEN TO A DEALER WHERE IT WAS CONFIRMED THAT THE TIRE READ SEPARATED AND NEEDED TO BE REPLACED. THE TIRES WAS NOT REPLACED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE APPROXIMATE VEHICLE FAILURE MILEAGE WAS 57,965 AND THE TIRE FAILURE MILEAGE WAS 3,500.
Seat belts
Reports naming seat belts, buckles, retractors and pretensioners.
From owner reports, verbatim
2009 MERCEDES BENZ C300. CONSUMER WRITES IN REGARDS TO PART OF THE SRS CONTROL UNIT MODULE WAS REPAIR, HEAD REST UNIT DEPLOYED WHILE DRIVING AND REPLACEMENT PARTS NOT AVAILABLE TO REPAIR AIRBAG RECALL. *SMD *TR
TAKATA RECALL WHEN I PURCHASED VEHICLE IT WAS ALREADY SALVAGE.
Fuel system
Reports naming fuel storage or delivery — tanks, pumps, lines, injectors and fuel leaks.
From owner reports, verbatim
The contact owns a 2009 Mercedes-Benz C300. The contact stated upon starting the vehicle, she became aware that the vehicle was leaking fuel. There was no warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The contact was informed that the fuel tank needed to be replaced. The vehicle was not repaired. The contact was related the failure to an unknown recall. The manufacturer was not informed of the failure. The failure mileage was approximately 120,000.
MY REAR SUBFRAME IS DROPPED MY AIRBAG LIGHTS KEEP COMING ON MY SUSPENSION IS TERRIBLE BECAUSE OF MY SUSPENSION MY REAR SUBFRAME HAD DROPPED AND MY LIGHT WARNING FOR MY LIGHTS KEEP COMING ON
Too few reports in this category for a page of its own — they appear in the full complaint list.
Other / unspecified
Reports whose component NHTSA recorded as unknown, or that do not map to one of the categories above.
From owner reports, verbatim
I bought this car for my 18 year old son based on Mercedes reputation for safety and longevity, only to discover that Mercedes has a widely acknowledged issue with rotted sub-frames -- it's a serious safety issue and recalled in other countries. My son was was driving on the highway and the tire exploded. He was so close to being killed because the car went out of control. After getting it towed to my mechanic, he advised me that alignment adjusters were stuck, the subframe was rotted, the lower control arm subframe mounts were broken from the subframe and they were hitting the gas tank. Luckily, the tire only exploded as oppose to the entire vehicle bursting in flames. There were no warning lights or messages, only the feeling that the tires needed to be aligned. We bought new tires and were told an alignment was done from Town Fair Tires, which was untrue. My son's life was in immediate danger. Shame on Mercedes for not recalling this subframe. This is the first of many avenues I am taking to have this rectified and hopefully prevent a tragedy
GOODYEAR ASSURANCE COMFORTRED 225/45R17 DEFECTIVE. SEVERAL CRACKS ON SIDEWALL OF ALL 4 TIRES. FRONT TIRES WITH 16,458 MILES AND REAR TIRES AT 25,000 MILES. LF TREAD 8/32 RF 9/32. REAR: 6/32 AND 8/32. I FORWARDED PICTURES TO GOODYEAR AND FILED A COMPLAINT 11/30/2018
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
I drove my car to get lunch. Came back out to go back to work and the car would not start. Would not even turn over. My Radio did not turn on and I couldn't even roll my windows back up. Luckily they were only cracked open a small amount. My steering wheel cannot be turned, it's locked in it's current position. I am told the ESL (Electronic Steering Lock) and possibly the EIS is the cause of this problem. The display on the dash says "Take your key from ignition" and that is all I get. Had to have my car towed and now I have a dead car with the windows partially open that I cannot close.
Rear Subframe gets rusted and breaks is an issue with most of mercedes c300 to the point the part is back order in USA and Germany its a safety issue and there should be a recall for it when I called mercedes benz they told me they get at least 3 to 4 calls a day about that issue and people can't find the part it's a comment issue and it sounds be resolved.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Interior & seats
Reports naming seats, latches, locks, linkages and interior fittings.
From owner reports, verbatim
WHILE DRIVING DOWN THE HIGHWAY, AT A LITTLE OVER 50 MPH, WITH MY CHILDREN IN THE CAR, THE DRIVER SIDE HEADREST NECK RESTRAINT SUDDENLY DEPLOYED. I FELT LIKE I WAS PUNCHED IN THE BACK OF THE HEAD AND IT COULD HAVE CAUSED AN ACCIDENT. I DROVE IT TO A MERCEDES DEALERSHIP AND WAS TOLD THAT IT IS COMMON AND THAT EVEN DRIVING OVER RAILROAD TRACKS CAUSES THE HEADREST NECK RESTRAINTS TO DEPLOY. I DIDN'T DRIVE OVER RAILROAD TRACKS OR EVEN A POTHOLE SO IT MAKES NO SENSE TO ME. WHEN I GOT HOME I WAS ABLE TO GET A CLOSER LOOK AT IT TO SEE THAT MOST OF THE INSIDE IS PLASTIC. I THINK MERCEDES BENZ SHOULD BE HELD RESPONSIBLE FOR THE REPLACEMENT. THE INCIDENT HURT ME AND PUT ME AND MY FAMILY IN DANGER. THERE SHOULD BE A RECALL ON THIS.
I PURCHASED THIS VEHICLE IN 2009 AND OVER THE YEARS I HAVE REPLACED BOTH FRONT HEADLIGHT ASSEMBLY, LEFT AND RIGHT AT THE COST OF $800.00 EACH. I WAS TOLD THAT A BULB BLEW FUSING THE WIRES TOGETHER RESULTING IN THE REPLACEMENT OF THE ENTIRE ASSEMBLY. THE DRIVER SEAT HEAD REST SIMPLY FELL APART.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .