IllustrationVehicle experienced sudden engine failure while driving due to timing chain failure on N47 diesel engine, a known defect. Loss of propulsion occurred without warning, creating a safety risk.
2014 BMW 328D
Owner reports · Recalls · Investigations
Limited comparison data
There is not enough comparable history to draw a useful model-year comparison.
About this comparison →How this year compares
Owner complaints by model year
Compare all 328D 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
110–25K
1025–50K
2250–75K
1975–100K
17100–150K
9150K+
88 reports with mileage · 63 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.
- Engine. Review the 57 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Fuel/propulsion System. Review the 47 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Fuel System, Diesel. Review the 23 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
5 crash reports11 fire reports1 injury reports
Engine complaints
57 reportsI am reporting an emissions-related malfunction that occurred a very short time after BMW performed the EGR cooler recall and updated the DDE software on my vehicle. Shortly after the recall work, the vehicle began showing DDE fault code 2BB300 – Particulate Sensor Measuring Electrode, Self-Diagnosis, which triggered the MIL. Th…
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I am reporting an emissions-related malfunction that occurred a very short time after BMW performed the EGR cooler recall and updated the DDE software on my vehicle. Shortly after the recall work, the vehicle began showing DDE fault code 2BB300 – Particulate Sensor Measuring Electrode, Self-Diagnosis, which triggered the MIL. This issue did not exist at any point before the recall. Although my vehicle is now older than 10 years, the critical concern is that this emissions-related failure appeared soon after the recall intervention, indicating a potential recall-associated defect rather than normal age-related wear. The fault was diagnosed at BMW West Houston, where it was confirmed; however, I was told no warranty or goodwill support could be provided due to vehicle age, despite the timing suggesting a recall-related cause. BMW’s emissions warranty extension bulletin (NHTSA TSB ID: MC-10160282-9999) lists particulate sensor failures (2BB700–2BA200) as known issues. Many BMW diesel owners have reported similar particulate sensor faults shortly after the EGR cooler recall and related software changes, suggesting a broader pattern. If the EGR recall or subsequent software calibration is leading to particulate sensor failures and MIL activation, this may represent a post-recall emissions defect affecting compliance. I request that NHTSA evaluate whether the EGR recall may be contributing to widespread particulate sensor failures. Vehicle Information: – 2014 BMW Diesel – Fault Code: 2BB300 – Failure occurred a short time after the EGR cooler recall & software update – Diagnosed at: BMW West Houston Thank you for your attention.
The primary failure involves the EGR cooler system covered under Recall 21V-907, with consequential damage to the intake system, including intake air leaks, charge pipe failure, displaced turbo-to-DPF V-band clamp, brittle/cracked fuel lines, and intake system integrity loss. Yes — the vehicle and all affected components are ava…
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The primary failure involves the EGR cooler system covered under Recall 21V-907, with consequential damage to the intake system, including intake air leaks, charge pipe failure, displaced turbo-to-DPF V-band clamp, brittle/cracked fuel lines, and intake system integrity loss. Yes — the vehicle and all affected components are available for inspection upon request The EGR cooler internal leak defect and intake system failures create risk of engine overheating, thermal degradation, loss of engine power under boost, exhaust gas leakage, and potential fire hazard, which can cause unsafe driving conditions and sudden loss of vehicle performance The vehicle was presented to a BMW dealership, and the recall defect was acknowledged. The dealer confirmed that any decisions regarding inspection and repair must come from BMW corporate. The dealership refused to inspect or evaluate the recall-related failures pending corporate authorization. No. BMW of North America has not authorized inspection or evaluation. The dealership also refused to inspect the vehicle pending corporate direction. Yes. Symptoms included audible air leaks, intake pressure loss under boost, performance degradation, and component failures occurring both before and after recall repair attempts. These symptoms developed during the period when the vehicle was operating under a known recall-defect condition and continued after recall repair.
a check engine light came on codes say it's the EGR valve and cooler dealer states since recalls are vin related there was not much they can do recall states its based by manufactured day not vin
Check engine light came on and codes suggest it's the egr valve and cooler may be leaking
12/2023 - Sewell BMW replaced EGR, all H/P fuel lines at injectors due to corrosion, injector harness due to heat damage to the wire jackets, cracked coolant pipe. At 145,976 that's an additional 22,315 miles on the 60,000 mile 2015 replacement engine. Total repair costs $3,939.45. 08/23/2024 - Passed inspection, odometer 149…
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12/2023 - Sewell BMW replaced EGR, all H/P fuel lines at injectors due to corrosion, injector harness due to heat damage to the wire jackets, cracked coolant pipe. At 145,976 that's an additional 22,315 miles on the 60,000 mile 2015 replacement engine. Total repair costs $3,939.45. 08/23/2024 - Passed inspection, odometer 149,701. 09/09/2024- Only 2 weeks later an estimate of 4,000 miles after replacing injector harness and H/P fuel lines, engine went up in flames, reason unknown. Pictures attached, vehicle was a total loss.
[XXX] - Purchase vehicle, odometer 109,803. 11/2019 - Car went into limp mode while driving on highway. Towed to BMW dealership and was advised needed new engine, at the time it only had 123,661 miles on it. Towed to EurAuto Shop for installation of replacement engine. 02/2020- The shop replaced the ceased OEM engine with …
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[XXX] - Purchase vehicle, odometer 109,803. 11/2019 - Car went into limp mode while driving on highway. Towed to BMW dealership and was advised needed new engine, at the time it only had 123,661 miles on it. Towed to EurAuto Shop for installation of replacement engine. 02/2020- The shop replaced the ceased OEM engine with a 2015 engine, with only 60,000 miles on it. EurAuto Shop tore down OEM engine and confirmed the timing chain guide broke, resulting in jumped timing and caused valve to hit piston. Total cost for engine replacement $6,641.49. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
There was a recall to replace EGR cooler on this car. Dealer replaced with same defective design EGR cooler. BMW is not putting any effort in redesigning EGR cooler and install that one in customer's cars. We are again risking our lives with new but defective design EGR cooler.
stall/loss of power while entering highway on ramp. Engine died and would not restart. After inspecting car found the gas tank to be filled with metal shavings which is indicative of a failed high pressure fuel pump. My year make and model vehicle has a recall on the HPFP for the same reason but my VIN was supposedly not affecte…
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stall/loss of power while entering highway on ramp. Engine died and would not restart. After inspecting car found the gas tank to be filled with metal shavings which is indicative of a failed high pressure fuel pump. My year make and model vehicle has a recall on the HPFP for the same reason but my VIN was supposedly not affected.
The contact owns a 2014 BMW 328D. The contact stated while driving at an undisclosed speed, there was exhaust fumes inside the cabin of the vehicle. The vehicle was taken to the dealer, where the engine was flushed; however, the failure recurred. The contact related the failure to NHTSA Campaign Number: 21V907000 (Fuel System, D…
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The contact owns a 2014 BMW 328D. The contact stated while driving at an undisclosed speed, there was exhaust fumes inside the cabin of the vehicle. The vehicle was taken to the dealer, where the engine was flushed; however, the failure recurred. The contact related the failure to NHTSA Campaign Number: 21V907000 (Fuel System, Diesel). The manufacturer was not made aware of the failure. The failure mileage was approximately 121,000.
Official recalls
724V527000 · Air Bags:frontal:driver Side:inflator Module
Jul 11, 2024
BMW of North America, LLC (BMW) is recalling certain 2015 6 Series Gran Coupe, 2014 5 Series Gran Turismo, 2014 5 Series Sedan, 2015 6 Series Convertible, 2015 6 Series Coupe, 2014 X5, 2013-2014 X3, 2014-2015 3 Series Sedan, 2014 4 Series Coupe, 2014 4 Series Convertible, 2014 3 Series Gran Turismo, and 2015 4 Series Gran Coupe vehicles. Please see the recall report for the complete list of models. The driver's air bag inflator may explode during deployment, due to a manufacturing defect.
Consequence & remedy
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, increasing the risk of injury or death.
Remedy: The driver's front air bag will be replaced, free of charge. Owner notification letters were mailed September 6, 2024. Owners may contact BMW customer service at 1-800-525-7417.
24V288000 · Air Bags:side/window
Apr 24, 2024
BMW of North America, LLC (BMW) is recalling certain 2014-2015 2 Series Coupe (228i, 228i xDrive, M235i), 3 Series Sedan (320i, 320i xDrive, 328i, 328i xDrive, 335i, 335i xDrive, M3, 328d, 328d xDrive), 4 Series Coupe (428i, 428i xDrive, 435i, 435i xDrive, M4), and 2015 4 Series Gran Coupe (428i, 428i xDrive, 435i, 435i xDrive) vehicles. The head air bag inflator may fail at the weld joint, which can cause gas to leak from the inflator or result in an inflator rupture.
Consequence & remedy
Consequence: An inflator that ruptures may cause sharp metal fragments to enter or exit the vehicle, increasing the risk of injury. Additionally, an inflator that leaks gas may only partially inflate during a crash, increasing the risk of injury.
Remedy: Dealers will replace the head air bags, free of charge. Owner notification letters were mailed November 4, 2024. Owners may contact BMW customer service at 1-800-525-7417.
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.
20V185000 · Power Train:driveline:constant Velocity Joint
Mar 26, 2020
BMW of North America, LLC (BMW) is recalling certain 2013-2016 328d xDrive sedans and 2013-2015 328d xDrive station wagon vehicles. The constant-velocity joint which transfers power between the transfer case and the rear drive shaft, may become damaged, possibly resulting in loss of power to the rear wheels.
Consequence & remedy
Consequence: A loss of power to the rear wheels can affect vehicle control, increasing the risk of a crash. Additionally, when the vehicle is parked after a loss of power to the rear wheels and the parking brake is not engaged, unintended rollaway can occur, increasing the risk of a crash or injury.
Remedy: BMW will notify owners, and dealers will replace the constant-velocity joint and inspect the transfer case, replacing it if necessary, free of charge. The recall began May 22, 2020. 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.
15V520000 · Exterior Lighting
Aug 17, 2015
BMW North America, LLC (BMW) is recalling certain model year 2012-2015 320i, 320xi, 328i, 328xi, 335i, 335xi, and ActiveHybrid3 vehicles manufactured October 20, 2011, to June 22, 2015, 2014-2015 328xi Sports Wagon vehicles manufactured March 21, 2013, to March 17, 2015, 2014-2015 328d, 328xd vehicles manufactured June 28, 2013, to April 21, 2015, and 2014-2015 328xd Sports Wagon vehicles manufactured July 5, 2013, to April 21, 2015. The affected vehicles may have been programmed with new software that inadvertently makes the front side marker lights inoperative in conjunction with the parking lights or the headlights. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 108, "Lamps, Reflective Devices, and Associated Equipment."
Consequence & remedy
Consequence: If the side marker lights do not illuminate, the vehicle may be less visible at night, increasing the risk of a crash.
Remedy: BMW will notify owners, and dealers will upload revised software to correct the issue, free of charge. The recall began on October 7, 2015. Owners may contact BMW customer service at 1-800-525-7417 or by email at CustomerRelations@bmwusa.com.
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
2EA23001 · 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.