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.
Pedal Operation Interference
EA15003
Closed engineering analysis · opened April 1, 2015 · closed September 1, 2015 · led to recall 15V507000
the hydraulic brakes, vehicle speed control
On August 11, 2015, Nissan North America, Inc., submitted a Defect Information Report (DIR) describing a condition that may impede the driver's ability to transition quickly and smoothly from the accelerator pedal to the brake pedal in certain model year (MY) 2012 through 2015 Nissan Versa Sedans and MY 2014 through 2015 Nissan Versa Note vehicles (NHTSA Recall No. 15V-507).According to Nissan's DIR, in certain circumstances related to driver foot position and shoe type, the right edge of the driver?s shoe may catch the edge of the center console lower trim panel.Nissan indicated that this condition could cause a slight delay in the smooth transition between the accelerator pedal and the brake pedal which may increase the braking distance; therefore increasing the risk of a crash.Nissan's recall instructs dealers to trim the console panel so that the leading edge is at a greater distance from the driver?s foot.Nissan had previously issued a service campaign (Nissan Campaign ID #P5308; TSB #NTB15-033) on April 16, 2015, to provide the remedy for the same set of vehicles before deciding to change the program to a safety recall.Of the approximately 421,305 vehicles covered by recall 15V-507, approximately 122,558 have already been repaired under the service campaign. ODI's investigation also examined allegations that an HVAC duct in the driver's footwell area may interfere with the driver's right foot in certain circumstances.ODI's analysis of all complaints related to foot obstructions in the subject vehicles identified 45 complaints, 7 crashes and 1 minor soft tissue injury.Thirty-five (35) of the complaints, all 7 crashes and the only injury were caused by the trim panel condition which is the subject of the recall.ODI will continue to monitor complaints related to the HVAC duct condition.This investigation is closed based on Nissan's recall.The VOQs associated with the closing of this investigation are: 10725339, 10723544, 10711794, 10691631, 10649259, 10640644, 10629161, 10614957, 10610356, 10606832, 10606766, 10606670, 10597004, 10573057, 10503811, and 10498000.
Excessive Brake Pedal Travel
PE14014
Closed preliminary evaluation · opened May 20, 2014 · closed May 13, 2015
the brakes, the hydraulic brakes
On May 20, 2014, ODI opened PE14-014 based on eight complaints alleging incidents of excessive brake pedal travel in model year (MY) 2013 through 2014 Nissan Sentra, Versa Sedan and Versa Note passenger cars (Figure 1) and information in Early Warning Reporting field reports indicating issues with master cylinder internal seals.In response to an information request letter sent by ODI, Nissan identified a condition with the master cylinder in early production subject vehicles that could result in a slow internal leak past one of the recuperating seals to the brake reservoir when the brake pedal is depressed very slowly or lightly (Figure 2).The subject vehicles are equipped with fixed seal master cylinders supplied by TRW.To address concerns with water hammer noise with the standard seal design, the master cylinders in the early production subject vehicles used AWH (anti-water hammer) seals.The AWH seals are sensitive to contamination from assembly plant cleanliness issues, which can produce the internal leak condition during slow or light brake applies but perform as designed with normal or emergency brake applications.TRW indicated that the risk of contamination interacting with the subject seals is greatest after the evacuation and pressure fill process used to fill the brake system during the manufacturing process (early life issue).TRW developed a new master cylinder seal design (EVO seal) that addresses the noise concern and eliminates the internal leak concern associated with contamination by providing a secondary seal (Figure 3).Nissan implemented the new master cylinder design in vehicle production on September 23, 2013.ODI's analysis shows that the master cylinder warranty claim rate is much higher in vehicles produced before the change (Figure 4).Statistical analysis showed that the condition is an early-life problem with relatively low failure rates projected through 100,000 miles and approximately 58 percent of the failures projected to occur by that mileage have already occurred (Table 1).Warranty claims are highest (78% of claims) in vehicles with less than 10,000 miles (Figure 5) and 50 percent of claims involved vehicles with less than 90 days in service (Figure 6).ODI evaluated 22 crash claims that included allegations of master cylinder failure, sinking brake pedal or pedal to the floor (Table 2).The analysis identified only three crashes in which a brake performance issue related to the master cylinder was duplicated by post-incident inspection, including one with a different problem than the seal leak issue (a broken plunger).The two crash complaints related to a possible master cylinder concern involved 1 vehicle with the AWH seal and 1 with the EVO seal.Both were minor crashes.The remaining crashes do not appear to be related to any issues with the master cylinder or other brake system fault.In the 4 crashes with Event Data Recorderinformation available, the data indicated that the brakes were applied too late to avoid the collisions.These include 2 crashes with less than a half second of braking before impact and 2 in which brake applications lasting 1.0 to 2.5 seconds resulted in high decelerations consistent with fully functioning brake systems, but too late to avoid the collision.Overall, the rates of crashes adjusted for vehicle exposure (total vehicle years in service) do not show any correlation to the high warranty rates associated with the AWH seal leak concern (Table 3 & Figure 7).Given these circumstances, further use of the agency resources in this matter does not appear to be warranted.Accordingly, this investigation is closed. The closing o