STRUCTURE:BODY:ROOF AND PILLARS
2015 Mercedes-Benz C400
Recalls, owner-reported complaints, investigations and safety data
Data refreshed
Overview
Our database contains 10 NHTSA owner-reported complaints for the 2015 Mercedes-Benz C400, most frequently naming the body & structure, driver assistance and electrical categories. 8 safety recalls have been issued covering this model year; 2 NHTSA investigations name it; and 114 manufacturer communications are on file.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Complaint activity over time
When owners filed reports about this model year
View as table
| Month | Complaints filed | Cumulative |
|---|---|---|
| Oct 2015 | 1 | 1 |
| Jan 2016 | 1 | 2 |
| Sep 2017 | 1 | 3 |
| Sep 2021 | 1 | 4 |
| Feb 2024 | 1 | 5 |
| Jun 2024 | 1 | 6 |
| Aug 2024 | 1 | 7 |
| Nov 2024 | 1 | 8 |
| Feb 2025 | 1 | 9 |
| Aug 2025 | 1 | 10 |
What owners report
Complaints grouped by the component NHTSA recorded
- Body & structure654.5%
- Driver assistance19.1%
- Electrical19.1%
- Engine19.1%
- Suspension19.1%
- Visibility19.1%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Safety recalls
8 campaigns cover this model year
Recalls apply to specific vehicles, not to every vehicle of a model year. Check your VIN with NHTSA or your manufacturer's dealer to confirm whether a recall affects your vehicle.
Check a VIN on NHTSA.govSTRUCTURE:BODY:ROOF AND PILLARS
COMMUNICATION
Safety investigations
NHTSA inquiries naming this vehicle. An investigation is not a finding of a defect.
Desiccated Air Bag Inflator Rupture
From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.Consequently, all frontal inflators using propellant 2004 that do not contain a "desiccant" (a substance that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replaced.In some cases, the remedy part for these recalled inflators was, or will be, an inflator using either propellant 2004 or 2004L that does contain a desiccant. None of these "desiccated" remedy parts (which were installed in older model year vehicles) are currently under recall for a degradation concern. Certain subsets of desiccated PSAN inflators using propellant 2004 for use as original equipment, however, have been recalled for a degradation concern. All Takata inflators produced with propellant 2004L contain desiccant, and none of these desiccated inflators using propellant 2004L are under recall for a degradation concern. There have been no reported field ruptures in any non-recalled desiccated PSAN inflators.It is understood that desiccants fully saturate at some threshold, at which point any additional moisture will not be captured. This means the degradation process observed in non-desiccated inflators using propellant 2004 may also occur in non-recalled desiccated inflators using propellant 2004, assuming additional moisture enters the inflator and high temperature cycling occurs. Based on available information, desiccant saturation can occur within the first five years in the worst environments, and the time required for full saturation is affected by multiple factors. While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004.Three entities -- Takata (now known as TK Global), the Independent Testing Coalition, and Exponent -- have been studying the long-term behavior of Takata desiccated PSAN inflators using propellant 2004L (as well as 2004) in the presence of moisture and temperature cycling. The research efforts, which include development of predictive modeling techniques and field sample analysis, are ongoing. To date, none of the researchers have identified field evidence showing that propellant 2004L is undergoing a degradation process that leads to aggressive deployment and potential rupture. However, the time in service of such inflators remains short compared to that of the inflators using propellant 2004. Further study is needed to assess the long-term safety of desiccated inflators using propellant 2004L.The Office of Defects Investigation is opening this investigation to examine whether a safety defect related to propellant degradation exists in non-recalled desiccated PSAN frontal inflators manufactured by Takata. This investigation will require extensive information on Takata production processes and surveys of inflators in the field. Lists of recall actions that may have used desiccated PSAN inflators as remedy parts, as well as the makes and models originally manufactured with them, is available with the downloadable version of this document (see nhtsa.gov/recalls?nhtsaId=EA21002 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.
Front Roof Panel Detachment
On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel detachments while driving at highway speeds in certain 2015 Mercedes-Benz (Mercedes) C-Class vehicles.The subject front roof panel is a stationary panel composed of polycarbonate and is attached to the vehicle via adhesive at the time of manufacture. The panel is found on subject vehicles equipped with panoramic sunroofs. Over time, the subject panels may exhibit cosmetic degradation leading to replacement of the panel, a procedure which entails: removal of the old panel and adhesive, site preparation, and installation of a replacement panel with new adhesive.The consumer complaints that prompted the opening of PE21-001 all described detachments of front roof panels that had been replaced after the vehicle was put into service.Mercedes' internal investigation identified a broader scope of affected vehicles (2014-2020 CLA, GLA, C, S, GLC, and GLE class) and found the following potential service procedure- related causes of front roof panel detachments:- Improper surface pretreatments such as the use of the wrong primer or cleaner or scoring of the surface; or - Use of the incorrect adhesive.These conditions lead to a front roof panel bond that, even if sound at the time of repair, cannot maintain its strength over time and environmental exposure.Mercedes updated its service and parts ordering systems to reinforce the proper use of specified kits and procedures via webinars, shop foreman meetings, and explicit reference to the risks incurred by diverging from the repair procedures. Mercedes is also furnishing parts ordering assistance, and will hold dealerships accountable for improper repairs.ODI's analysis of the ten complaints it has received from the public (VOQ's) and MBUSA's complaint data submitted in response to the information request letter for PE21-001 identified a total of 57 non-duplicative reports alleging incidents in which the front roof panel detached from the vehicle while in motion. Included within the 57 reports are incidents where consumers state the panel detached ...and flew off into traffic.On March 19, 2021, Mercedes notified NHTSA that it would recall subject vehicles with front roof panels known to have been replaced after the original sale of the vehicle. In total, the recall (designated as Recall 21V197) covers 15,099 vehicles that were ever registered in the United States. Based on Recall 21V197 and the remedy implemented by Mercedes, further investigation does not appear to be warranted at this time.Accordingly, this investigation is closed.The ODI complaints cited above can be viewed at www.nhtsa.gov under the following ODI identification numbers: 11376425, 11352686, 11351629, 11349158, 11341541, 11337594, 11324100, 11311591, 11222127, 11404183
Recent owner complaints
Reports submitted to NHTSA, shown in the owner's own words
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 ID
- 11679248
- Incident
- Feb 8, 2025
- Mileage
- 100,000 mi
Rear subframe cracked while driving and rear of car sways from one lane to the next when brakes are applied. Car is not safe
- NHTSA ID
- 11641763
- Incident
- Jan 1, 2025
The contact owns a 2015 Mercedes-Benz C400. The contact stated that while the vehicle was being serviced, the contact was informed by the dealer that the rear subframe needed to be replaced. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was 112,000.
- NHTSA ID
- 11623121
- Incident
- Oct 31, 2024
- Mileage
- 112,000 mi
The contact owns a 2015 Mercedes-Benz C400. The contact stated while driving 55-60 MPH, the front roof panel separated and flew off. The contact drove back and was able to pick the front roof panel off the road. The vehicle was taken to the dealer, where it was determined that the front roof panel needed to be replaced. Additionally, the dealer informed the contact that the recall repair of NHTSA Campaign Number: 21V197000(Structure) was previously performed on the vehicle, and the additional related repair would be at the contact's expense. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 23V854000(Structure). The manufacturer was not notified of the failure. The failure mileage was approximately 74,000.
- NHTSA ID
- 11607566
- Incident
- Aug 9, 2024
- Mileage
- 74,000 mi
My boyfriend and I were driving my 2015 MB C400 down the road in November 2020 and it was a beautiful day out so we decided we would open the sunroof to get some fresh air. I was driving so my boyfriend pressed the button for the sunroof to open. As the sunroof was opening, there was a cracking and popping sound coming from above us. We immediately pulled over at a gas station to see what was happening. Upon getting out of the car and looking closer at the sunroof, we noticed many cheap plastic components that were just broken and crumbled laying inside the sunroof tract. We removed the broken pieces and then tried to close the sunroof several times. T Each time, the sunroof went into the closed position BUT immediately went straight back to the popped up position and would not completely close again. I took my car to the MB dealership in Athens, Ga where they told me it would be almost $2500 to repair which I did not feel as if I should be held responsible for as I had just purchased the car in January 2020 only 11 months earlier. I was in fear that the sunroof would detach from the car and cause serious injury to any motorist behind me. I also have a [XXX] son who is now scared to ride in my car!! After doing much research on this issue, I have found that this is truly a common problem with this MB model. I have reached out to the corporate office a few times and they only tell me that there is no active recalls with my cars VIN. It is completely unacceptable that MB is fully aware of this issue yet they continue to disregard the potential harm to other motorists. Please help!!! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- NHTSA ID
- 11595949
- Incident
- Nov 15, 2020
My car failed PA State inspection due to a hole and rusted rear subframe. I have determined that there is a recall associated with this issue but that my vehicle just missed the recall limit. The recall affected 2008-2015 models (C Class with chassis 204). My vehicle is a 2015 C Class with chassis 205. It is evident that my vehicle has the same structural/construction defects as the previous years and should have been included in this recall. I have provided photographic evidence (attached/uploaded below). This is a very expensive repair that I should not have to pay for. Please review and consider having this included in the recall process so that I can be reimbursed for this costly repair as it is the result of a faulty construction process. Thank you. Sincerely, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
- NHTSA ID
- 11570624
- Incident
- Feb 7, 2024
Panoramic glaaa sunroof mounting bracket made of cheap thin plastic that it breaks easily allowing the panoramic glass roof to fly off the car if driven while open.
- NHTSA ID
- 11431700
- Incident
- Aug 27, 2021
ENGINE RANDOMLY STALLS AFTER SITTING AT RED LIGHT/OR WHILE IN TRAFFIC. ALL WARNING/DASHBOARD LIGHTS COME ON AND YOU CAN ONLY START THE CAR BY PUTTING IT IN PARK, THEN PUSHING START. THE CAR HAS LESS THAN 10K MILES. DEALERSHIP CAN'T FIND CODE OR REPLICATE THE ISSUE. INTERNET SEARCHES INDICATE IT IS AN ISSUE AND OTHER MAKES AND MODELS HAVE BEEN RECALLED, BUT WITHOUT A CODE THE DEALERSHIP DOESN'T KNOW WHAT TO DO. I WAS NEARLY REAR-ENDED BECAUSE IT DOESN'T HAPPEN UNTIL YOU TAKE YOUR FOOT OFF THE BRAKE AND PRESS THE GAS TO MOVE FORWARD, AND THAT'S WHEN THE ENGINE SHUTS OFF COMPLETELY. THIS HAPPENS RANDOMLY AND HAS HAPPENED SEVERAL TIMES.
- NHTSA ID
- 11021610
- Incident
- Aug 29, 2017
- Mileage
- 9,700 mi
Manufacturer communications
A bulletin sent by a manufacturer to its dealers. Not a recall, and repairs are not necessarily free.
STEERING
Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering system when steering (see attachment). Complaint does not impact the ability to safely steer or control the vehicle. Cause Ball screw drive (KGT) of electric steering damaged by: 1. External force due to: ‑ Hitting the curb/posts with the front wheels. ‑ Driving over obstacles (e.g. pothole/ threshold/ speed bump/ gully) at an inappropriate speed. 2. Corrosion/ water ingress through a damaged boot (see attachment). ‑ Cracks (1) ‑ High pressure cleaner (2) ‑ Animal bite (3) See various examples listed in the attachments for examples of outside influence. Remedy Remove boot clamps closest to steering gear housing on both left and right (as seen in "Steering Rack Boot Clamp Location"). Pull back boot and inspect for rust, broken end stops, water, or any other anomalies. Replace electric steering. Note: Steering gears replaced due to outside influence or damage must not be claimed under warranty!
ELECTRICAL SYSTEM; STRUCTURE:BODY
Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so that the tailgate no longer opens as a result of a long press on the button, but by double‑clicking on the button instead. This reduces the likelihood of the button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc (O for Oscar, not "zero") • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key (a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.
ELECTRICAL SYSTEM
Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause Various root causes Remedy See attached diagnostic guide.
ELECTRICAL SYSTEM
Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car 5.Speech Detection Service 6.Navigation 7.iHeartRadio 8.Traffic Cams Cause MB Apps is sundowned for all vehicles with NTG4.5 and NTG5 Head Unit Variant. Remedy No support available for NTG4.5 and NTG5 Head Unit Variants for MB App related topics. Note: Please do not create TIPS. Please do not replace any components. HU/Hermes SW update / SCN coding will not fix the issue.
STRUCTURE:BODY
Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10-P-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim!
POWER TRAIN
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).
Manufacturers file copies of the bulletins they send to dealers with NHTSA. These often describe diagnostic or repair procedures for a known condition. They are not recalls: repairs described in a bulletin are usually only free if the vehicle is still under warranty or the manufacturer has extended coverage.