2015 Mercedes-Benz C 300 Recalls

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.

In a letter dated April 29, 2022, Mr. Sergio Betancourt (the petitioner) submitted a petition attributing engine failure of his 2015 Mercedes-Benz C300 to “wrong sized wrist-pins” and asserted that these were prevalent on all Mercedes-Benz models (including the Metris minivan, GLC300, and C300) equipped with a version of the M274 engine. The petition cited Mercedes Technical Service Bulletin (TSB) LI03.10-P-060916 (meant for the 2015 C300) and postulated that the “wrong-sized wrist pin” would allow the piston to “wiggle in the cylinder as it would move up and down”. In addition to the Mercedes-Benz TSB, the petitioner enclosed a service center repair estimate and images of other online submissions discussing the M274 engine. In the incident that prompted the petition, the petitioner reported that the vehicle lost power and shook in response to accelerator application during highway driving, followed by white smoke from the exhaust pipe. The petitioner stated that the subsequent service center visit led to a cracked piston diagnosis. The service record from this visit prescribed an engine teardown to localize the failure and characterize any resulting engine damage and listed a number of repair options that included replacement of one piston, four pistons, or the entire engine long block (depending on the level of damage suffered). TSB LI03.10-P-060916 (“TSB”) was first released on February 27, 2015 and pertained to Engine Code 274.920. It cited the following complaint condition: “Clattering/rattling or knocking noise from the crank assembly of the engine when cold at oil temperatures up to approximately 50°C mostly heard on engine deceleration” and listed the cause as under analysis. The TSB gave further instructions on the collection of information and discouraged the replacement of any components. On September 21, 2015, TSB Version 4 introduced engine build clean points (March 27, 2015 or April 20, 2015 depending on the engine plant); cause: unfavorable tolerance of the piston wrist pin resulting in enlarge end float of the connecting rod in the piston; and remedy: compare the complaint vehicle sound to an enclosed sound file under various operating conditions and then if verified, replace the pistons, connecting rods, and bearings, using updated pistons that include updated wrist pins. A review of the petitioner’s vehicle service history indicates that this labor operation was performed in March of 2016. In its November 22, 2022 response to ODI's September 28, 2022 Information Request (IR) letter, Mercedes stated that the limited number of potentially affected wrist pins could contribute to an unintended noise, but pose no motor vehicle safety risk. ODI's analysis of the field data furnished with the Mercedes IR response and within its own Vehicle Owners Questionnaire (VOQ) database support this assertion, finding no relationship between wrist-pin conditions cited in the TSB and engine failure or loss of motive power. Broader searches of both data sources for engine stalling related to engine durability identified no trends meriting further investigation. After conducting a technical review of the petitioner’s submissions, the vehicle history of the petitioner's vehicle, Mercedes TSB—LI03.10-P-060916, information provided by Mercedes-Benz in response to the Agency's Information Request, and data within its own files; NHTSA has concluded that there is insufficient evidence to pursue a formal investigation. Accordingly, the Agency has denied the petition. NHTSA will continue to review any new information or incidents as they are submitted to the Agency. A Federal Register Notice (FRN) further detailing NHTSA's reasons for denial of the petition will be published in the future. The petition and its attachments can be reviewed at NHTSA.gov under reference ODI number 11450360.

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