An investigation means NHTSA has decided a pattern is worth examining. A
preliminary evaluation is often closed with no action; an engineering
analysis is the stage that usually precedes a recall.
Desiccated Air Bag Inflator Rupture
EA21002
Still open engineering analysis · opened September 17, 2021
the air bags
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.
Seat belt buckle bracket failure
PE19008
Closed preliminary evaluation · opened July 29, 2019 · closed December 12, 2019 · led to recall 19V680000
the seat belts
On July 17, 2019, NHTSA's Office of Defects Investigation (ODI) opened Preliminary Evaluation (PE) 19-008 after receiving three Vehicle Owner Questionnaire (VOQ) reports alleging the driver's side seat belt buckle separated from the seat frame, rendering the seat belt non-functional. The VOQs involved model year (MY) 2015 and 2016 Jeep Wrangler (JK platform) that were configured for right-hand drive (RHD) use. On August 8, 2019, ODI issued an information request (IR) letter to FCA.The scope of the IR included all JK Wrangler produced for sale in the U.S. (both left- and right-hand drive), and amongst other things, requested any reports or allegations of driver's seat belt bracket failures on these vehicles. In its review of FCA's response, ODI determined that approximately 1.7 million JK Wrangler were produced from MY 2007 to 2018, about 16,000 of which were configured for RHD. ODI notes that the RHD Wrangler are typically used for rural postal delivery which often experience a more severe duty cycle. Also RHD JK was was not produced in MY 2007.As explained in the IR response, FCA identified three distinct populations of JK Wrangler concerning the driver's seat belt bucket bracket; specifically the MY 2007-2018 LHD (~1.7M units), the MY 2008-2010 RHD (4,563 units), and the MY 2011-2018 RHD (11,463 units) populations.FCA provided details on the designs used in each of these populations, identifying specific differences deemed pertinent to the strength and durability of each unique bracket design. FCA further reviewed its analysis of the complaint and warranty data identified under the IR, and noting that it had not identified any allegations of bracket failures on the LHD population, and only one allegation on the MY 2008-2010 RHD vehicles. By comparison, FCA identified 24 allegations of bracket failure for the MY 2011-2018 RHD JK, including two reports duplicative of the VOQs. Neither the FCA nor the VOQ reports allege an injury or fatality due to bracket failure. Based on this analysis, FCA decided to conduct a safety recall for the MY 2011-2018 RHD JK population. On September 30, 2019, FCA submitted a Defect Information Report initiating NHTSA Safety Recall 19V-680 (FCA No. VA6). Under the recall action, FCA will replace the driver's seat belt bracket on MY 2011-2018 RHD Jeep JK Wrangler. The repair will be conducted free of charge.In view of FCA's recall action, and its explanations of the scope of that action, ODI is closing PE19-008. ODI will continue to monitor the non-recalled RHD, and the LHD JK Wrangler for evidence of seat belt bracket failure and will take further action if warranted.The three VOQ reports cited above can be reviewed at NHTSA.gov under the following reference numbers:11190251, 11218472, 11231639.
Electrical overstress
EA19001
Closed engineering analysis · opened April 19, 2019 · closed September 19, 2024 · led to recall 20V024
the air bags
The Office of Defects Investigation (ODI) opened this investigation to determine if the failure of airbags to deploy during severe crashes, in certain vehicles, was the result of a safety related defect. During the investigation a complex failure was studied that can result in non-deployment of subject vehicle air bags and other restraint system devices in severe crash events. The subject vehicles may be equipped with an airbag control unit (ACU) for the supplemental restraint system (SRS) Electronic Control Unit (ECU) manufactured by ZF-TRW. The ECU receives signals from crash sensors mounted in the vehicle and deploys the vehicle air bags and seat belt pretensioners in accordance with manufacturer design specifications. The ECU in the subject vehicles contains a model DS84 application-specific integrated circuit (ASIC) which controls the communication of the crash sensor signal, firing commands (i.e., when to deploy the airbag(s) and/or pretensioners), and fault information (e.g., diagnostic trouble codes). In September 2016, FCA announced recall 16V-668 for certain model year (MY) 2010 to 2014 Chrysler, Dodge and Jeep products manufactured with the subject ZF-TRW ACU. In this recall, FCA discussed an EOS condition that resulted in a failure of the subject DS84 ASIC, which caused air bag non-deployment. FCA noted that the defect condition had only been observed in vehicles equipped with sensor harnessing routed across the front of the vehicle. Other FCA vehicles that also used the subject ACU, but were not equipped with cross-car harnessing, had not experienced EOS failures, despite similar time in service. During the course of this investigation, ODI sent two separate Information Request (IR) letters to six vehicle manufactures (including FCA, Hyundai, Honda, Kia, Mitsubishi, and Toyota) and one IR letter to ZF-TRW. These IR letters resulted in ODI receiving comprehensive data from these manufacturers and suppliers. Studies of this data found that the DS84 ASIC does not have sufficient protection against negative electrical transients or electrical overstress (“EOS”) that can be generated in certain severe crashes. An electrical transient occurs when the electrical power supplied to a circuit changes momentarily over a short duration of time. In these severe crash cases, the crash sensors and other powered wiring can be damaged and short circuited so as to create a negative electrical transient of sufficient intensity and duration (that are outside the vehicle manufacturer's specification) to damage the ASIC before the restraint device deployment signal is received by the SRS ECU. This damaged signal can lead to incomplete or nondeployment of the air bags and/or pretensioners. Airbag non-deployment and/or lack of pretensioner operation can increase the risk or severity of injury in a crash.A total of 8 fatalities and 14 injuries were associated with known EOS events. The common element in all investigated manufacturers vehicles is the SRS ECU containing a DS84 ASIC manufactured by ZF-TRW. The risk associated with the ASIC is equally shared among all OEMS involved in the investigation. The actual real-world risk can be mitigated by other factors which were assessed by ODI during this investigation. The first mitigating factor involves protections built into the ACU design which protect the DS84 ASIC from damage. There are multiple strategies and levels of protection employed by different OEMs that provide effective EOS mitigation. The two most common strategies at the ACU level are circuit protection diodes on the remote senor signal lines, and current limiting resistors that protect critical components. The second mitigating factor is found at the vehicle level and involves the location and routing of the wires leading from the crash sensors to the SRS ECU. If the wires are well protected in a crash and are not routed with other power wires carrying large currents, the risk for an EOS event is significantly reduced or eliminated. These design specific factors combine to produce a spectrum of risk for the vehicles equipped with ACUs using the DS84 ASIC. Given the many of years of field exposure, it is possible to divide the subject population into two groups; vehicles which have experienced EOS events, and vehicles which have not experienced EOS field events. Four of the six OEMs involved in this investigation have experienced EOS field events on at least one of their models equipped with a DS84 ASIC. All vehicle models (including the Toyota models identified in the Failure Report Summary of the opening resume for this investigation) with field events have been recalled. In an abundance of caution, ODI kept this investigation open five years to monitor field performance and did not identify any field events on vehicles not included in existing safety recalls. Given the spectrum of risk identified in this investigation and that all vehicles with a demonstrated unreasonable risk have been recalled, ODI is closing this investigation. ODI is closing this investigation with the following manufacturer safety recalls: 16V-668, 18E-043, 18V-137, 18V-363, and 20V-024. With the recall actions taken by the subject vehicle and equipment manufacturers, this investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exists on other model or model year vehicles outside of the recall scopes. The agency reserves the right to take further action if warranted by the circumstances.