EA17003 · Engine Compartment Fire
Opened Sep 1, 2017 · Closed Aug 21, 2018
Status: closed (inferred from source dates) · Engine
On April 30, 2018, Mercedes-Benz USA, LLC, (Mercedes-Benz) submitted a Defect Information Report (DIR) to NHTSA regarding a defect that could result in a vehicle fire starting from the engine compartment in 42,781 model year (MY) 2008 and 2009 Smart Fortwo cabrio and coupe vehicles (451 platform).According to Mercedes-Benz?s DIR, ?the rear insulation mat within the engine compartment might deform, deteriorate, loosen and over time, subsequently be able to contact hot components of the exhaust system.This could lead to an ignition of the insulation mat and possible fire in the engine compartment.?The US-specification exhaust system has an external catalytic converter packaged close to the insulation mat, where temperatures in the vicinity of the insulation mat reach high values.Over time, these temperatures can lead to a change in the insulation mat's material characteristics and ultimately allow the material to deform. Depending on the magnitude and the specific location of the deformation, the insulation mat could contact hot components of the exhaust system and ignite.Mercedes-Benz will replace the rear insulation mat on the affected vehicles with the improved mat first implemented in the United States in MY 2010 vehicles.ODI?s analysis of fire incident field data reported to NHTSA and Mercedes-Benz show an increasing trend of non-crash fires in the subject vehicles that begins after 4 years of service and accelerates after 7 years of service.The analysis shows that this trend is driven by fires occurring in the engine compartment.Forensic investigations of fires occurring in the past year identified the insulation mat as a likely or possible cause of most of the fires originating in the engine compartment.This investigation is closed based on Mercedes-Benz insulation mat recall.For more information about field data trends and fire investigations, see the closing resume in the document file for this investigation.
PE16016 · Engine Compartment Fire
Opened Dec 16, 2016 · Closed Nov 20, 2017
Status: closed (inferred from source dates) · Engine
On December 16, 2016, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE16-016 to investigate eight complaints alleging incidents of engine compartment fire while driving or shortly after engine shutdown in model year (MY) 2008 through 2009 Smart Fortwo vehicles.The complaints appeared to indicate an increasing trend, with all eight fires occurring since January 2015.As part of PE16-016, ODI analyzed information related to incidents reported to the Office by consumers, analyzed field data and technical information submitted by Mercedes-Benz USA (Mercedes) in response to the PE16-016 information request letter, and analyzed non-crash vehicle fire claim data provided by the Highway Loss Data Institute (HLDI).To date, ODI's analysis of incidents reported by consumers and provided by Mercedes has identified 27 incidents of open flame fires originating in the engine compartments of the subject vehicles, 14 of which were reported to ODI by Vehicle Owner Questionnaires (VOQs) and 18 involving complaints or field reports to Mercedes (5 of the incidents were reported to both ODI and Mercedes).One incident reported to Mercedes includes an allegation of an injury from smoke inhalation.Nineteen (19) of the incidents occurred since January 2015.Mercedes has only investigated 2 of the 27 fire incidents, and the company was unable to identify a vehicle-based cause for either incident.To further assess incident rates and trends, ODI requested fire claim data for the subject vehicles and eight peer vehicles from the Highway Loss Data Institute (HLDI).HLDI collects insurance claim data from companies representing over 80 percent of the market for private passenger vehicle insurance in the United States.ODI?s analysis of the HLDI data, which covered the period from 2010 through late-2016, found that the MY 2008 Fortwo vehicles had a significantly higher claim frequency than its peers and, similar to ODI?s complaint trend, experienced a sharp increase in claims in 2015.This investigation has been upgraded to an Engineering Analysis (EA17-003) to continue to investigate the high frequency and increasing trend of non-crash engine compartment fire incidents in the subject vehicles.The VOQs associated with the opening of this investigation were:10676359, 10780222, 10790017, 10820891, 10872656, 10944676, 10916505, 10924311, 10924637, 10939504, 10945296, 10993895, 11011100, 11011565.
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