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2016 BMW 535D

Owner reports · Recalls · Investigations

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There is not enough comparable history to draw a useful model-year comparison.

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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

Limited mileage data: 3 of 9 reports include usable mileage. There isn’t enough coverage to show a useful chart.

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.

  • Engine. Review the 4 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Fuel System, Diesel. Review the 3 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Fuel/propulsion System. Review the 1 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

0 crash reports1 fire reports0 injury reports

What owners actually said

9 reports
Mileage unknown · Jul 29, 2025
Engine

On [XXX], the coolant connector flange on my 2016 BMW 535d (VIN: [XXX] ) catastrophically failed, causing complete coolant loss. I immediately contacted BMW of Las Vegas and was instructed to drive it in despite fluid visibly leaking through the undercarriage. The next day, [XXX], BMW performed Recall 21V-907 (EGR cooler replace…

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On [XXX], the coolant connector flange on my 2016 BMW 535d (VIN: [XXX] ) catastrophically failed, causing complete coolant loss. I immediately contacted BMW of Las Vegas and was instructed to drive it in despite fluid visibly leaking through the undercarriage. The next day, [XXX], BMW performed Recall 21V-907 (EGR cooler replacement), which involved draining and reconnecting the coolant circuit—but they left the failed flange in place. The failed flange connects directly to the new EGR coolant return hose installed under the recall. BMW had full access to the part but chose not to inspect or replace it. The dealer submitted a consequential damage claim to BMW North America, which was denied. The vehicle remains at the dealership unrepaired. This failure poses serious safety risks. Driving with active coolant loss could cause overheating, engine failure, or fire. Had I not stopped, this could’ve led to mechanical catastrophe. BMW re-pressurized the cooling system into a visibly broken flange, creating an unsafe condition. The failure was confirmed by BMW technicians and documented in a repair order. No warning lamps were active at the time of failure. I currently have an open case with BMW North America, but no contact has been made. I am requesting NHTSA review this matter as BMW failed to fully remedy a safety defect and ignored collateral damage tied directly to the recalled system. The failed part is available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI #11676996

116,000 miles · Apr 14, 2025
Fuel System, Diesel

The contact owns a 2016 BMW 535D. The contact stated while driving approximately 25 MPH, the vehicle experienced a loss of motive power. No warning lights were illuminated. The vehicle was towed to a local dealer where it was diagnosed with high-pressure fuel pump failure. The vehicle was left at the local dealer, where it remai…

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The contact owns a 2016 BMW 535D. The contact stated while driving approximately 25 MPH, the vehicle experienced a loss of motive power. No warning lights were illuminated. The vehicle was towed to a local dealer where it was diagnosed with high-pressure fuel pump failure. The vehicle was left at the local dealer, where it remained for further repairs. The vehicle was not repaired. Upon further investigation, the contact related the failure to NHTSA Campaign Number: 21V586000 (Fuel System, Diesel); however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 116,000.

NHTSA ODI #11654425

Mileage unknown · Apr 4, 2025
EngineFire

Valve cover leak Oil filter housing leak Super common that these items leak in the bmw N57 diesel engines. Increased risk of fire. I am in the Facebook group with many other owners of the same engine, and almost everyone runs into the same problems by 100,000 miles.

NHTSA ODI #11652697

Mileage unknown · Jul 25, 2024
Fuel/propulsion System

HIGH PRESSURE FUEL PUMP HAS SUDDENLY FAILED CAUSING A IMMEDIATE ENGINE STALL WITHOUT WARNING. WILL NOT RESTART EVEN THOUGH IT DOES TURN OVER. CODE READS LOW FUEL PRESSURE AT FUEL RAIL. FUEL TANK LIFT PUMP IS WORKING CORRECTLY. THERE IS A RECALL FOR SOME 2014 TO 2016 535D FOR THIS FAILURE. WHY IS MINE NOT COVERED? 122,400 MILES.

NHTSA ODI #11604602

Mileage unknown · Aug 12, 2022
EnginePower Train

A recall campaign No. 21V-907 was issued for my car on November 19, 2021 for the EGR Cooler. In the past 6 months I've had to add engine coolant to the cooling system reservoir and I made sure it is not leaking on the ground. On 8-8-22 I had a check engine light(MIL) with a stored code of P2004 which indicated: Intake manifol…

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A recall campaign No. 21V-907 was issued for my car on November 19, 2021 for the EGR Cooler. In the past 6 months I've had to add engine coolant to the cooling system reservoir and I made sure it is not leaking on the ground. On 8-8-22 I had a check engine light(MIL) with a stored code of P2004 which indicated: Intake manifold runner control (IMRC) is stuck in the open position. According to your recall letter, an EGR Cooler leak could develop and the coolant could mix with the soot deposits in the intake manifold and under certain conditions it could result in a fire. I have experienced a reduction in engine power, a warning symbol of low engine coolant, and an unpleasant exhaust odor so I contacted Stevens Creek BMW in San Jose, CA and spoke to the Service Manager. He said they are not able to fix my car due to the BMW EGR Cooler not being available. Can you help?

NHTSA ODI #11479056

65,000 miles · Aug 2, 2022
EngineFuel System, Diesel

The contact owns a 2016 BMW 535D. The contact stated that the engine warning light was illuminated. The contact received notification of NHTSA Campaign Number: 21V907000 (Fuel System, Diesel) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer …

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The contact owns a 2016 BMW 535D. The contact stated that the engine warning light was illuminated. The contact received notification of NHTSA Campaign Number: 21V907000 (Fuel System, Diesel) however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. VIN tool confirms parts not available. The approximate failure mileage was 65,000.

NHTSA ODI #11477184

Mileage unknown · Jan 21, 2022
Fuel System, Diesel

The contact owns a 2016 BMW 535D. The contact received a recall notification for NHTSA Campaign Number: 21V907000 (Fuel System, Diesel) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not…

Read full complaint

The contact owns a 2016 BMW 535D. The contact received a recall notification for NHTSA Campaign Number: 21V907000 (Fuel System, Diesel) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was notified of the issue. The contact had not experienced a failure. VIN tool confirms parts not available.

NHTSA ODI #11448370

Mileage unknown · Oct 3, 2018
Unknown Or Other

REDUCTANT TANK SENSOR FAILURE

NHTSA ODI #11133207

16,000 miles · Mar 5, 2018
Tires

1 ST TIRE BLOWN 13000 MILES AT 45 MPH ON LAKE HAVASU CITY,AZ 2ND TIRE BLOWN 16000 MILES AT 65 ON 5FWY LOS ANGELES,CA AT 14 000 MILES HAD TO REPLACE A TIRE FOR A PUNTURE SO NO BIG DEAL BUT 3 GOODYEAR EAGLE LS 245/45R18 RUN ON FLAT BEFORE 20 000 MILES THATS A CONCERN SAFE TO DRIVE THE CAR

NHTSA ODI #11076396

Official recalls

5

21V907000 · Fuel System, Diesel

Nov 19, 2021

BMW of North America, LLC (BMW) is recalling certain 2013-2018 328d, 328d xDrive, 2014-2018 328d Sports Wagon, 328d xDrive Sports Wagon, 2014-2016 535d, 535d xDrive, 2015 740Ld xDrive, 2015-2017 X3 xDrive28d SAV, and 2014-2017 X5 xDrive35d SAV diesel vehicles equipped with an Exhaust Gas Recirculation (EGR) module with an integrated cooler. The EGR cooler may leak internally, causing coolant to mix with diesel engine soot, which could result in smoldering particles and a melting intake manifold.

Consequence & remedy

Consequence: A melting intake manifold increases the risk of a fire.

Remedy: Dealers will replace the EGR cooler and inspect the intake manifold, replacing it as necessary, free of charge. This recall includes all vehicles previously recalled under 18V-755. Vehicles previously recalled under 18V-755 will need to have the new remedy performed for this recall. An interim owner notification letter was mailed on January 18, 2022. The remedy is expected to be available in June 2022. Owner notification letters were mailed on July 6, 2022. Owners may contact BMW customer service at 1-800-525-7417.

21V586000 · Fuel System, Diesel:delivery:fuel Pump

Jul 29, 2021

BMW of North America, LLC (BMW) is recalling certain 2014-2018 328d, 328d xDrive, X5 xDrive35d, 2014-2016 535d, 535d xDrive, 2015 740Ld xDrive, and 2015-2017 X3 xDrive28d vehicles. The high-pressure fuel pump may fail.

Consequence & remedy

Consequence: Fuel pump failure can cause an engine stall while driving, increasing the risk of a crash.

Remedy: Dealers will replace the high-pressure fuel pump, free of charge. Owner notification letters were mailed on January 14, 2022. Owners may contact BMW customer service at 1-800-525-7417.

18V755000 · Engine And Engine Cooling:exhaust System:emission Control:gas Recirculation Valve (egr Valve)

Oct 25, 2018

BMW of North America, LLC (BMW) is recalling certain 2013-2018 BMW 328d and 328d xDrive, 2014-2018 328d Sports Wagon and 328d xDrive Sports Wagon, 2014-2016 535d and 535d xDrive, 2015 740Ld xDrive, 2015-2017 X3 xDrive28d SAV and 2014-2017 X5 xDrive35d SAV vehicles equipped with an Exhaust Gas Recirculation (EGR) module with an integrated cooler. If the EGR cooler leaks internally, the coolant can mix with diesel engine soot. The high EGR temperatures may result in these particles possibly smoldering and melting the intake manifold.

Consequence & remedy

Consequence: The melting intake manifold can increase the risk of a fire.

Remedy: BMW will notify owners, and dealers will inspect and replace the EGR cooler as necessary. If a leak has already occurred, the engine intake manifold will also be replaced. These repairs will be made free of charge. The recall began May 13, 2019. Owners may contact BMW customer service at 1-800-525-7417.

16V914000 · Air Bags

Dec 20, 2016

BMW of North America, LLC (BMW) is recalling certain model year 2017 BMW 640i, 640i xDrive, 650i, 650i xDrive, M6, 535i, 535i xDrive, 430i, 430i xDrive, 440i, 440i xDrive, M4, X1 sDrive28i, X1 xDrive28i, i3, i8, Rolls-Royce Dawn, Mini Clubman Cooper, Clubman Cooper S, Cooper All4, Cooper S All4, Mini 4-Door Cooper, Cooper S, Mini 2-Door Cooper, Cooper S, John Cooper Works and 2016 BMW 528i, 528i xDrive, 535i, 535i xDrive, 550i, 550i xDrive, M5 and 535d vehicles. The affected vehicles have seat- mounted side air bag inflator initiators that may fail to ignite during a crash.

Consequence & remedy

Consequence: If the air bag inflator initiator fails to ignite, the seat-mounted air bag will not deploy, increasing the risk of injury.

Remedy: BMW will notify owners, and dealers will replace the air bag modules, free of charge. The recall began February 6, 2017. Owners may contact BMW customer service at 1-800-525-7417.

15V718000 · Child Seat; Seats:mid/rear Assembly

Oct 30, 2015

BMW of North America, LLC (BMW) is recalling certain model year 2016 528i, 528i xDrive, 535i, 535i xDrive, 535d xDrive, M5, 550i, 550i xDrive, and 535d sedans. The affected vehicles have an inboard lower anchor for child restraints on the left rear seat that may have been bent downwards, preventing the child seat from fully engaging both lower anchors. As such, these vehicles may fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 225, "Child Restraint Anchorage Systems."

Consequence & remedy

Consequence: If the child seat is not properly attached to the lower anchors, it can increase the child's risk of injury in the event of a crash.

Remedy: BMW will notify owners, and dealers will inspect and, if necessary, repair the inboard lower anchor on the left rear seat, free of charge. The recall began on December 28, 2015. Owners may contact BMW customer service at 1-800-525-7417.

Additional source detail variants (2)

Child Seat

BMW of North America, LLC (BMW) is recalling certain model year 2016 528i, 528i xDrive, 535i, 535i xDrive, 535d xDrive, M5, 550i, 550i xDrive, and 535d sedans. The affected vehicles have an inboard lower anchor for child restraints on the left rear seat that may have been bent downwards, preventing the child seat from fully engaging both lower anchors. As such, these vehicles may fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 225, "Child Restraint Anchorage Systems."

Consequence: If the child seat is not properly attached to the lower anchors, it can increase the child's risk of injury in the event of a crash.

Remedy: BMW will notify owners, and dealers will inspect and, if necessary, repair the inboard lower anchor on the left rear seat, free of charge. The recall began on December 28, 2015. Owners may contact BMW customer service at 1-800-525-7417.

Seats:mid/rear Assembly

BMW of North America, LLC (BMW) is recalling certain model year 2016 528i, 528i xDrive, 535i, 535i xDrive, 535d xDrive, M5, 550i, 550i xDrive, and 535d sedans. The affected vehicles have an inboard lower anchor for child restraints on the left rear seat that may have been bent downwards, preventing the child seat from fully engaging both lower anchors. As such, these vehicles may fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 225, "Child Restraint Anchorage Systems."

Consequence: If the child seat is not properly attached to the lower anchors, it can increase the child's risk of injury in the event of a crash.

Remedy: BMW will notify owners, and dealers will inspect and, if necessary, repair the inboard lower anchor on the left rear seat, free of charge. The recall began on December 28, 2015. Owners may contact BMW customer service at 1-800-525-7417.

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

2

EA23001 · High Pressure Fuel Pump Failure

Opened Mar 17, 2023 · No close date supplied

Status: open (inferred from source dates) · Fuel System, Diesel:delivery:fuel Pump

The Office of Defects Investigation (ODI) opened PE21-021 on October 14, 2021, to investigate incidents alleging a stall/loss of motive power as a result of high-pressure fuel pump failures in certain model year (MY) 2019-2020 Ram 2500, 3500, 4500, and 5500 heavy duty trucks equipped with 6.7L Cummins turbodiesel engines. During the investigation, ODI sought to determine if the related defect allegation was limited in scope to the recalled population. After review of information request response materials from both FCA and BMW, NHTSA determined that sufficient information to identify a comprehensive recall population could not be produced by FCA and BMW.During the investigation FCA filed recalls 22V406, 22E048, 22V767, and 22E087 which include vehicles not identified in the initial subject population by ODI. ODI also received recall 21V586, involving loss of motive power due to failed CP4 fuel pumps on certain BMW manufactured vehicles. An information request letter response received from BMW indicated that failed pumps on their vehicles were caused by an interaction between pump internal components and US market diesel fuel, leading to increased slip and eventual particle-generating wear surface. Additional work will be done to identify whether a similar root cause is associated with the FCA recalled population and if similar wear dynamics occur on pumps supplied to vehicle manufacturers other than those included in the recalled population.ODI has upgraded this investigation to an EA in order to 1) determine engineering specifications of internal pump components that are correlated with pump failure leading to loss of motive power or other safety related hazards, 2) identify vehicle populations equipped with alleged defective pump variants, 3) assess if vehicles equipped with alleged defective pump variants result in an unreasonable risk to motor vehicle safety and 4) gather and review any other relevant information related to high pressure fuel pump failure associated with the subject populations of recalls 21V586, 21V880, 21E094, 22V406, 22E048, 22V767, and 22E087.Review of the above information will allow NHTSA to confirm root cause and recall remedy viability, and identify and evaluate vehicle populations equipped with pump components that may pose an unreasonable risk to motor vehicle safety.The ODI reports cited above can be reviewed at: http://www-odi.nhtsa.dot.gov/owners/SearchNHTSAID using the following complaint identification numbers: 11257550, 11351441, 11361603, 11361616, 11365300, 11365426, 11365858, 11366401, 11372337, 11373793, 11374797, 11376793, 11377871, 11378173, 11384377, 11386063, 11387018, 11399710, 11402550, 11415339, 11418868, 11418870, 11427075, 11434276, 11436807, 11437226, 11437249, 11437273, 11437292, 11437294, 11437394, 11437399, 11437403, 11437405, 11437423, 11437528, 11437565, 11437579, 11437580, 11437590, 11437679, 11437744, 11437781, 11437842, 11437993, 11438006, 11438008, 11438121, 11438138, 11438155, 11438392, 11438629, 11439359, 11439879, 11440397, 11443030, 11446542, 11448163, 11453556, 11458918, 11460558, 11469337

EA21002 · 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.