2018 Mercedes-Benz C 300

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.

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

Front roof panel came detached at hwy speed

NHTSA ID

11764699

Incident

Sep 13, 2026

The contact owns a 2018 Mercedes-Benz C-300. The contact stated that while driving 70 MPH South on the interstate towards Miami, the front panel detached without warning. The contact pulled over to inspect the vehicle and became aware that the panel between the windshield and sunroof had detached. The contact stated that water started entering the vehicle from several areas. The sunroof was inoperable. The contact called the insurance company. The contact associated the failure with NHTSA Campaign Number: 23V854000 (Structure). The local dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but no additional assistance was provided. The approximate failure mileage was 83,000.

NHTSA ID

11759626

Incident

Aug 6, 2026

Mileage

83,000 mi

Transmission failed, yes available for inspection Very bad safety issue Yes it has been confirmed by dealship Yes by the deanship Yes there was warning lamps that appeared in January 2026

NHTSA ID

11744612

Incident

Jan 5, 2026

The contact's wife owns a 2018 Mercedes-Benz C300. The contact stated that while washing the vehicle, a part of the panoramic roof started moving while depressing the glass. The contact stated that there was water leaking into the vehicle from the glass. Upon investigation, the contact discovered NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was filed. The manufacturer confirmed that the VIN was not included in the recall. The contact was then referred to the NHTSA Hotline to report the failure. The failure mileage was unknown.

NHTSA ID

11722229

Incident

Sep 5, 2025

Check engine light comes on, Error Code P052E, after a lot of research, this is a known defective part by Benz. Huge safety issue not addressed by them. Very costly to fix for a customer. There is a new and improved replacement part from Benz indicating they are aware of the faulty old parts that are currently in those cars but yet they have failed to do a recall.

NHTSA ID

11709871

Incident

Jan 7, 2026

My vehicle only had 31,000 miles and I experienced engine failure. I bought a new engine for 16, 500. 00 dollars. Mercedes Benz did nothing. I almost got in to several accidents because the engine completely stop on the interstate. Almost got hit by several cars. This is unacceptable.

NHTSA ID

11695170

Incident

May 29, 2025

Rearview Camera is not displayed when the vehicle is placed in reverse. The display shows a black screen. A Recall Notice has been published for other vehicles of the same year, make, and model. The failure of the Rearview Camera results in safety risks during normal use of the vehicle.

NHTSA ID

11692113

Incident

Sep 17, 2025

I have noticed the driver seat belt not retracting after usage. Upon looking online I saw a post about a recall. Called local Benz dealership and BenzUSA customer service both said my Vin is not part of the specified recall.

NHTSA ID

11689895

Incident

Sep 25, 2025

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!

Complaint • Harsh 1‑2, 2‑3, and/or 3‑4 shift • Jerky shifting • Jolting when accelerating from stop Cause Insufficient software application causing elevated K81/K27/B05 fill time adaptations and elevated torque adaptations for concerning shift. Note: Shift quality in E Performance models can be affected if the HV Battery state of charge (SOC) reaches 25% or below. Remedy Check VGS software level, and follow relevant remedy instructions. (see attachment) AMG 43 models with VGS software levels up to 22A: As of 4/18/2025, an aftersales software improvement has been released. This software has been implemented in production as of model year 2024, however this LI should still be followed if the concern is present. 232 ‑ A0009025699 206 ‑ A0009025599 Please ensure your Xentry machine is up to date with the latest Add Ons and continue with the following steps: Note: ALL steps must be performed to rectify concern 1. Perform software update all control units included in VGS software update. 2. Check transmission oil level and correct, if necessary (transmission oil temperature > 60 °C) 3. Perform Xentry Valve Flushing procedure at least 3x 4. Perform resetting of deceleration values (VGS > Special Procedures > Special procedure > Resetting learned values Deceleration mode) 5. Perform a standstill adaptation, then read out new EEPROM data 6. Perform driving adaptation(s) while adhering to the below parameters for at least 20‑30 miles. Note: There is no menu in Xentry for this procedure. We recommend displaying the torque in the instrument cluster. If all below parameters are met at the time the shift, a driving adaptation will automatically occur. Harsh 1‑2 Perform a driving adaptation of 4‑5 (adapts K81 for the 1‑2 shift) Harsh 2‑3 Perform a driving adaptation of 6‑7 (adapts B05 for the 2‑3 shift) Harsh 3‑4 Perform a driving adaptation of 3‑4 (adapts K27 directly) ‑ See attached PDF for min/max torque, and RPM parameters ‑ Transmission oil temperature > 30°C (>86°F) ‑ Level track (no incline/decline) ‑ Slippery drive program ‑ Display the torque in the instrument cluster ‑ Constant engine torque ‑ Do not shift via paddle AMG 63 models with VGS software levels up to 22A: No aftersales software resolution is planned. Perform above steps and release the vehicle. If the vehicle returns and already had ALL steps in this LI performed on a previous visit, or has software level 23A and newer: Please submit a TIPS case to the Powertrain inbox and ensure the following is included: ‑ Initial Quick Test w/ Freeze Frame Data ‑ VGS Control Unit Log ‑ Initial EEPROM (before any adaptations or Xentry procedures were performed) ‑ Detailed vehicle history of the complaint

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.

Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the Diagnostic Module for Tank Leakage Detection ("DMTL") on your vehicle from the original New Vehicle Limited Warranty of 4 years / 50,000 miles to 15 years/150,000 miles (whichever occurs first). This applies to the vehicle regardless of ownership. Why the Warranty extension? On certain Model Year 2018 - 2024 A / C / CLA / CLS / E / G / GLA / GLB / GLC / GLE / GLS / GT / S / SL Mercedes-Benz vehicles, under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code ("DTC") entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp ("MIL"). Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. • If your preferred authorized Mercedes-Benz dealership performs a diagnosis and confirms that your vehicle has the issue, the repair will be covered under this extended warranty and performed at no cost to you. • This extended warranty does not apply to any other components or conditions beyond the ones mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet.

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.

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!