IllustrationTHIS IS THE 2ND WINDOW THAT HAS HAD TO BE REPLACED IN 2 1/2 YEARS. IT APPEARED TO CRACK SPONTANEOUSLY. *TR
2016 Subaru Outback
Owner reports · Recalls · Investigations
More warning signs than most Outback years
Owner complaints for the 2016 Subaru Outback are substantially higher than the model-year median of 207.5.
About this comparison →How this year compares
Owner complaints by model year
Compare all Outback years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
1290–25K
10925–50K
7450–75K
2075–100K
15100–150K
4150K+
351 reports with mileage · 292 unknown
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Electrical System. Review the 309 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Visibility/wiper. Review the 83 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Engine. Review the 53 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
22 crash reports3 fire reports8 injury reports
Visibility/wiper complaints
83 reportsTL* THE CONTACT OWNS A 2016 SUBARU OUTBACK. THE CONTACT STATED THAT WHILE DRIVING AT AN UNDISCLOSED SPEED, THE WINDSHIELD CRACKED WITHOUT IMPACT. THE CONTACT STATED THAT THE VEHICLE WAS PREVIOUSLY REPAIRED AT PEACOCK SUBARU HILTON HEAD (111 DRIVERS WAY SUITE A, HARDEEVILLE, SC 29927) FOR A CRACKED WINDSHIELD. THE VEHICLE WAS TAK…
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TL* THE CONTACT OWNS A 2016 SUBARU OUTBACK. THE CONTACT STATED THAT WHILE DRIVING AT AN UNDISCLOSED SPEED, THE WINDSHIELD CRACKED WITHOUT IMPACT. THE CONTACT STATED THAT THE VEHICLE WAS PREVIOUSLY REPAIRED AT PEACOCK SUBARU HILTON HEAD (111 DRIVERS WAY SUITE A, HARDEEVILLE, SC 29927) FOR A CRACKED WINDSHIELD. THE VEHICLE WAS TAKEN BACK TO THE SAME DEALER AND THE CONTACT WAS INFORMED THAT THE WINDSHIELD NEEDED TO BE REPLACED HOWEVER, NO ADDITIONAL ASSISTANCE WAS PROVIDED. THE WINDSHIELD WAS NOT REPLACED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 53,688.
MY VEHICLE WAS IN MOTION ON A HIGHWAY WHEN A PEBBLE STRUCK THE WINDSHIELD AND A CHIP WAS FORMED ON 8/26/2016. THIS CHIP WAS IMMEDIATELY REPAIRED. THIS WAS ONLY MONTHS FROM PURCHASING A BRAND NEW 2016 SUBARU OUTBACK; FACTORY TO DEALER. THEN, WHILE PARKED, IT WAS NOTED THAT THE CHIP FORMED A SPREADING CRACK ON 11/13/2017. AT TH…
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MY VEHICLE WAS IN MOTION ON A HIGHWAY WHEN A PEBBLE STRUCK THE WINDSHIELD AND A CHIP WAS FORMED ON 8/26/2016. THIS CHIP WAS IMMEDIATELY REPAIRED. THIS WAS ONLY MONTHS FROM PURCHASING A BRAND NEW 2016 SUBARU OUTBACK; FACTORY TO DEALER. THEN, WHILE PARKED, IT WAS NOTED THAT THE CHIP FORMED A SPREADING CRACK ON 11/13/2017. AT THIS POINT, THE WINDSHIELD WAS REPLACED WITH NEW, ORIGINAL SUBARU GLASS. *TR
MY WINDSHIELD SPONTANEOUSLY CRACKED ON THE DRIVER'S SIDE NEAR THE WIPER BLADE, WHILE DRIVING WITH A FACTORY WINDSHIELD. THE 6" CRACK FROM THE CORNER ALMOST IMMEDIATELY TURNED INTO A CRACK ACROSS THE ENTIRE WINDSHIELD - AGAIN NO TRAUMA OR ROCKS. I WAS DRIVING STRAIGHT ON A HIGHWAY WITH NO POTHOLES OR ANYTHING. I HAD THE WINDSHIEL…
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MY WINDSHIELD SPONTANEOUSLY CRACKED ON THE DRIVER'S SIDE NEAR THE WIPER BLADE, WHILE DRIVING WITH A FACTORY WINDSHIELD. THE 6" CRACK FROM THE CORNER ALMOST IMMEDIATELY TURNED INTO A CRACK ACROSS THE ENTIRE WINDSHIELD - AGAIN NO TRAUMA OR ROCKS. I WAS DRIVING STRAIGHT ON A HIGHWAY WITH NO POTHOLES OR ANYTHING. I HAD THE WINDSHIELD REPLACED AND IT HAS AGAIN SPONTANEOUSLY CRACKED WITH NO TRAUMA (NO ROCK OR BUG IMPACT OR OTHER IMPACTS/DAMAGES) ON THE PASSENGER SIDE BY THE WIPER BLADE. I BELIEVE THAT THE SUBARU WINDSHIELD AS WELL AS THE DEFROST SYSTEM ARE DEFECTIVE. THIS WILL BE MY THIRD WINDSHIELD IN UNDER 3 MONTHS. OTHER SUBARU OUTBACK OWNERS HAVE COMPLAINED ABOUT THIS AND SUBARU CONTINUES TO BLAME IT ON ROCKS. THE SECOND CRACK HAPPENED WHILE MY VEHICLE WAS STATIONARY IN THE DRIVEWAY!
IN FEBRUARY 2019 I HAD TO REPLACE THE WINDSHIELD IN MY 2016 SUBARU OUTBACK BECAUSE OF A CRACK THAT STARTED FROM THE PASSENGER SIDE EDGE FROM A VERY TINY CHIP, AND PAID ABOUT $950 (OEM EQUIPMENT AND DUE TO THE EYESIGHT SYSTEM CALIBRATION REQUIRED). ON FEBRUARY 29, 2020, I DISCOVERED A CRACK IN THE NEW WINDSHIELD, IN A SIMILAR PL…
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IN FEBRUARY 2019 I HAD TO REPLACE THE WINDSHIELD IN MY 2016 SUBARU OUTBACK BECAUSE OF A CRACK THAT STARTED FROM THE PASSENGER SIDE EDGE FROM A VERY TINY CHIP, AND PAID ABOUT $950 (OEM EQUIPMENT AND DUE TO THE EYESIGHT SYSTEM CALIBRATION REQUIRED). ON FEBRUARY 29, 2020, I DISCOVERED A CRACK IN THE NEW WINDSHIELD, IN A SIMILAR PLACE (PASSENGER SIDE, TINY CHIP AT THE EVERY EDGE (BLACK PART OF WINDSHIELD), THAT THEN EXTENDED HALF WAY ACROSS THE WINDSHIELD. I COULD NOT REMEMBER ANYTHING HITTING THE WINDSHIELD TO CAUSE THE TINY CHIP, AND IT REALLY WAS TINY AND VERY SHALLOW. THE CAR HAD BEEN PARKED ALL DAY IN A SAFE, SECURE AREA. THE CRACK WAS NOT THERE IN THE MORNING WHEN I PARKED THE CAR, BUT WAS THERE BY THE END OF THE DAY. PHOTO ATTACHED. IT DOES NOT SEEM REASONABLE TO HAVE TO REPLACE A WINDSHIELD ANNUALLY! SUBARU HAS A PROBLEM WITH THEIR WINDSHIELDS!
WINDSHIELD CRACKED IN L SHAPE . ON DAY AFTER SNOW FALL. WHEN CLEARED THERE WAS THE CRACK
I HAD PURCHASED MY CAR IN FEB 2016. WE HAD TO HAVE WINDSHIELD REPLACED 90 DAYS LATER. AND THEY TOLD ME " THE GLASS IS THINNER DUE TO EYE SIGHT. I'VE HAD WIND SHIELD REPLACED 2 OTHER TIMES SINCE THEN. WE WERE DRIVING DOWN THE HIGHWAY,AND IT WAS STRUCK BY ROCKS. I WENT TO SUBARU AND THEY STATED THERE WAS NOTHING WRONG WITH THEIR …
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I HAD PURCHASED MY CAR IN FEB 2016. WE HAD TO HAVE WINDSHIELD REPLACED 90 DAYS LATER. AND THEY TOLD ME " THE GLASS IS THINNER DUE TO EYE SIGHT. I'VE HAD WIND SHIELD REPLACED 2 OTHER TIMES SINCE THEN. WE WERE DRIVING DOWN THE HIGHWAY,AND IT WAS STRUCK BY ROCKS. I WENT TO SUBARU AND THEY STATED THERE WAS NOTHING WRONG WITH THEIR GLASS. AND EACH TIME IT WAS REPLACED. 1 AT THEIR COST AND 2 AT MIND. ALL OF THE PAPERS WORK I CAN GET FROM INS. COMPANY
I HAVE A 2016 SUBARU OUTBACK, WHICH I'VE OWNED SINCE NEW (09/15/2015). I'VE HAD TO REPLACE 8 WINDSHIELD SO FAR, SOMETIMES WITHIN 3 MONTHS, OR EVEN 2 DAYS APART. I DRIVE AROUND SAN FRANCISCO BAY AREA (NOT STATISTICALLY HIGHER RISK FOR WINDSHIELD DAMAGE) THIS CONSTANT ISSUE WITH THE WINDSHIELD AFFECTS THE SAFETY OF THE CAR IN CA…
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I HAVE A 2016 SUBARU OUTBACK, WHICH I'VE OWNED SINCE NEW (09/15/2015). I'VE HAD TO REPLACE 8 WINDSHIELD SO FAR, SOMETIMES WITHIN 3 MONTHS, OR EVEN 2 DAYS APART. I DRIVE AROUND SAN FRANCISCO BAY AREA (NOT STATISTICALLY HIGHER RISK FOR WINDSHIELD DAMAGE) THIS CONSTANT ISSUE WITH THE WINDSHIELD AFFECTS THE SAFETY OF THE CAR IN CASE OF FOREIGN OBJECT IMPACT OR SPONTANEOUS CRACKING, BECAUSE OF REDUCED VISIBILITY AND COMPROMISED STRUCTURAL/IMPACT PROTECTION
CRACK IN WINDSHIELD DIRECTLY BEHIND THE REARVIEW MIRROR HORIZONTALLY AND VERTICALLY WITH NO VISIBLE SIGNS OF IMPACT, FOUND ONE GETTING INTO THE CAR WHICH WAS IN OUR GARAGE
TL* THE CONTACT OWNS A 2016 SUBARU OUTBACK. THE CONTACT STATED THAT A FRACTURE WAS EVIDENT ON THE WINDSHIELD BY THE REAR VIEW MIRROR IN THE MIDDLE. THE CONTACT STATED THAT THE FRACTURE WAS HORIZONTAL OF WHERE THE REARVIEW MIRROR WAS ATTACHED. MICHAEL'S SUBARU OF BELLEVUE (15150 SE EASTGATE WAY, BELLEVUE, WA 98007 (425) 641-2002…
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TL* THE CONTACT OWNS A 2016 SUBARU OUTBACK. THE CONTACT STATED THAT A FRACTURE WAS EVIDENT ON THE WINDSHIELD BY THE REAR VIEW MIRROR IN THE MIDDLE. THE CONTACT STATED THAT THE FRACTURE WAS HORIZONTAL OF WHERE THE REARVIEW MIRROR WAS ATTACHED. MICHAEL'S SUBARU OF BELLEVUE (15150 SE EASTGATE WAY, BELLEVUE, WA 98007 (425) 641-2002) OFFERED FOR THE CONTACT TO HAVE THE VEHICLE TAKEN TO DEALER FOR A DIAGNOSIS AND INSPECTION. THE MANUFACTURER WAS NOT CONTACTED NOR INFORMED OF THE FAILURE. THE CONTACT STATED THAT THE INSURANCE COMPANY WOULD BE MADE AWARE OF THE ISSUE IF THE MANUFACTURER FAILED TO ASSIST IN HAVING THE VEHICLE REPAIRED. THE FAILURE MILEAGE WAS 40,000. THE VIN WAS NOT AVAILABLE.
Official recalls
419V910000 · Air Bags: Air Bag/restraint Control Module
Dec 19, 2019
Subaru of America, Inc. (Subaru) is recalling certain 2016-2017 Outback vehicles. A replacement air bag control module may have been installed that is not compatible with the passenger air bag module, possibly affecting air bag deployment.
Consequence & remedy
Consequence: In the event of a crash necessitating passenger frontal air bag deployment, the air bag may not deploy properly, increasing the risk of injury.
Remedy: Subaru will notify owners, and dealers will replace the passenger air bag module, free of charge. The recall began February 3, 2020. Owners may contact Subaru customer service at 1-844-373-6614. Subaru's number for this recall is WUX-09.
16V292000 · Steering:column
May 11, 2016
Subaru of America, Inc. (Subaru) is recalling certain model year 2016-2017 Legacy and Outback vehicles manufactured February 29, 2016, to May 6, 2016. The steering column on the affected vehicles may have been improperly machined, and as a result, turning the steering wheel may have no effect on the direction of the wheels.
Consequence & remedy
Consequence: The loss of steering ability would increase the risk of a crash.
Remedy: Subaru will notify owners, and dealers will inspect the lot number on the steering column, replacing the steering column, as necessary, free of charge. The recall began May 13, 2016. Owners may contact Subaru customer service at 1-800-782-2783 or by visiting http://www.wtd65.service-campaign.com. Subaru's number for this recall is WTD-65. Note: Until the vehicles have been inspected, owners are advised not to drive their vehicles.
15V794000 · Power Train:driveline:differential Unit; Power Train:driveline:driveshaft
Nov 24, 2015
Subaru of America, Inc. (Subaru) is recalling certain model year 2016 Legacy vehicles manufactured October 24, 2015, to November 16, 2015, and Outback vehicles manufactured October 24, 2015, to November 17, 2015. Due to the improper tightening of the securing nuts, the drive shaft may separate from the rear differential.
Consequence & remedy
Consequence: If the drive shaft detaches from the rear differential, it may strike the fuel tank and result in a fuel leak, increasing the risk of a fire.
Remedy: Subaru has notified owners, and dealers will inspect the fastening nuts, and tighten or replace them, as necessary, free of charge. The recall began on December 10, 2015. Owners may contact Subaru customer service at 1-856-488-8500. Subaru's number for this recall is WQV-57.
Additional source detail variants (2)
Power Train:driveline:differential Unit
Subaru of America, Inc. (Subaru) is recalling certain model year 2016 Legacy vehicles manufactured October 24, 2015, to November 16, 2015, and Outback vehicles manufactured October 24, 2015, to November 17, 2015. Due to the improper tightening of the securing nuts, the drive shaft may separate from the rear differential.
Consequence: If the drive shaft detaches from the rear differential, it may strike the fuel tank and result in a fuel leak, increasing the risk of a fire.
Remedy: Subaru has notified owners, and dealers will inspect the fastening nuts, and tighten or replace them, as necessary, free of charge. The recall began on December 10, 2015. Owners may contact Subaru customer service at 1-856-488-8500. Subaru's number for this recall is WQV-57.
Power Train:driveline:driveshaft
Subaru of America, Inc. (Subaru) is recalling certain model year 2016 Legacy vehicles manufactured October 24, 2015, to November 16, 2015, and Outback vehicles manufactured October 24, 2015, to November 17, 2015. Due to the improper tightening of the securing nuts, the drive shaft may separate from the rear differential.
Consequence: If the drive shaft detaches from the rear differential, it may strike the fuel tank and result in a fuel leak, increasing the risk of a fire.
Remedy: Subaru has notified owners, and dealers will inspect the fastening nuts, and tighten or replace them, as necessary, free of charge. The recall began on December 10, 2015. Owners may contact Subaru customer service at 1-856-488-8500. Subaru's number for this recall is WQV-57.
15V502000 · Power Train:automatic Transmission; Power Train:driveline:driveshaft
Aug 10, 2015
Subaru of America, Inc. (Subaru) is recalling certain 2015 and 2016 model year Subaru Legacy 4-Door and Outback vehicles manufactured July 3, 2015, to July 27, 2015. Transmission oil may leak from a deformed seal cap on the propeller shaft yoke.
Consequence & remedy
Consequence: If the transmission oil leaks onto the exhaust pipe, there is a possible risk of fire.
Remedy: Subaru will notify owners, and dealers will replace the propeller shaft, free of charge. The recall began on August 28, 2015. Owners may contact 1-800-782-2783. Subaru's number for this recall is WQU-56.
Additional source detail variants (2)
Power Train:automatic Transmission
Subaru of America, Inc. (Subaru) is recalling certain 2015 and 2016 model year Subaru Legacy 4-Door and Outback vehicles manufactured July 3, 2015, to July 27, 2015. Transmission oil may leak from a deformed seal cap on the propeller shaft yoke.
Consequence: If the transmission oil leaks onto the exhaust pipe, there is a possible risk of fire.
Remedy: Subaru will notify owners, and dealers will replace the propeller shaft, free of charge. The recall began on August 28, 2015. Owners may contact 1-800-782-2783. Subaru's number for this recall is WQU-56.
Power Train:driveline:driveshaft
Subaru of America, Inc. (Subaru) is recalling certain 2015 and 2016 model year Subaru Legacy 4-Door and Outback vehicles manufactured July 3, 2015, to July 27, 2015. Transmission oil may leak from a deformed seal cap on the propeller shaft yoke.
Consequence: If the transmission oil leaks onto the exhaust pipe, there is a possible risk of fire.
Remedy: Subaru will notify owners, and dealers will replace the propeller shaft, free of charge. The recall began on August 28, 2015. Owners may contact 1-800-782-2783. Subaru's number for this recall is WQU-56.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
1EA21002 · Desiccated Air Bag Inflator Rupture
Opened Sep 17, 2021 · No close date supplied
Status: open (inferred from source dates) · Air Bags:frontal:driver Side:inflator Module; Air Bags:frontal:passenger Side:inflator Module
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.
Additional source detail variants (2)
Air Bags:frontal:driver Side:inflator Module
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.
Air Bags:frontal:passenger Side:inflator Module
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.