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2015 BMW 328I

Owner reports · Recalls · Investigations

Similar to other model years

Owner complaints for the 2015 BMW 328I do not stand out strongly from the model-year median of 98.

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How this year compares

Owner complaints by model year

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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

48 reports with mileage · 76 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 56 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Engine And Engine Cooling. Review the 42 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Engine. 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.

6 crash reports8 fire reports2 injury reports

What owners actually said

124 reports
Mileage unknown · Sep 6, 2023
EngineFuel/propulsion System

Drivetrain malfunction warning comes on when the car runs for a few hours in the heat or when randomly driving. Sometimes the warning will clear itself after waiting a few minutes, but it might come back after a few minutes driving or not. In other instances, the drivetrain will not clear itself and will take more than a few hou…

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Drivetrain malfunction warning comes on when the car runs for a few hours in the heat or when randomly driving. Sometimes the warning will clear itself after waiting a few minutes, but it might come back after a few minutes driving or not. In other instances, the drivetrain will not clear itself and will take more than a few hours. Took it to the repair shop 3 times and they indicated it could be the fuel pump modular or spark plugs or it could just be that the heat is messing up the software system. The mechanic has mentioned that drivetrain malfunctions have been occurring more regularly with BMWs. The issue is that this drivetrain can malfunction at any random time. Driving on a highway, street, or just starting up the car after letting it sit for a few minutes or days. It's a safety hazard because it can happen at any time unexpectedly. When it does, the car goes into neutral and this is dangerous if driving on the highway at higher speeds and needing to pull over into right hand lane. I've not yet taken it to a dealer to look at, just a certified BMW repair shop. There have been no warning issues and the car clears whenever it is taken to the repair shop.

NHTSA ODI #11542816

Mileage unknown · Aug 22, 2023
EnginePower TrainSuspension

After consulting many others that own or previously owned 328i bmw from around the same years (2015-2017); a common issue was found and assumed to be the timing belt. when i press on the accelerator moderately/ as per usual, my RPMs and speedometer hesitate for a solid second then it will catch up and start shaking. i suspect it…

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After consulting many others that own or previously owned 328i bmw from around the same years (2015-2017); a common issue was found and assumed to be the timing belt. when i press on the accelerator moderately/ as per usual, my RPMs and speedometer hesitate for a solid second then it will catch up and start shaking. i suspect its the timing belt.

NHTSA ODI #11540161

97,500 miles · Aug 11, 2023
Air Bags

The contact owns a 2015 BMW 328I. The contact stated while starting the vehicle, the air bags warning light illuminated. The vehicle was taken to the dealer who stated that water had leaked into the trunk of the vehicle and onto the amplifier causing electrical shortage in the vehicle to stop functioning as designed. The contact…

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The contact owns a 2015 BMW 328I. The contact stated while starting the vehicle, the air bags warning light illuminated. The vehicle was taken to the dealer who stated that water had leaked into the trunk of the vehicle and onto the amplifier causing electrical shortage in the vehicle to stop functioning as designed. The contact was informed that an extensive diagnostic test was needed to locate the leak. Additionally, the contact was informed that the air bag positive terminal cable and the seat belt battery cable and amp needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and stated that there were no recalls on the VIN for the failure. The failure mileage was 97,500.

NHTSA ODI #11537953

Mileage unknown · May 8, 2023
Fuel/propulsion SystemService BrakesCrash

My son's 2015, BMW 328i was taken to BMW in Canton, Ohio due to "fluttering" in gas pedal and "possible transmission slipping and variations in transmission while driving. The check engine light was on and was diagnosed at dealership that the Mass Flow Sensor was malfunctioning. The wires to the Mass Flow Sensor were corroded a…

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My son's 2015, BMW 328i was taken to BMW in Canton, Ohio due to "fluttering" in gas pedal and "possible transmission slipping and variations in transmission while driving. The check engine light was on and was diagnosed at dealership that the Mass Flow Sensor was malfunctioning. The wires to the Mass Flow Sensor were corroded and needed fixed before sensor could be assessed. The wires were fixed and the check engine light went out so the car was considered by the BMW dealer service department to be fixed and I paid $545 for $42 in parts and $503 in labor. The service advisor named Mark, assured me that it had been test driven by service technician and that the car was in proper working condition. I picked the car up, for my son, at 10 am and drove south to West Virginia to deliver the car to my son. At 12:15, I pulled off the freeway and stopped at a light that was at a busy intersection, with a car in front of me. I came to a complete stop with my foot on the brake and my car accelerated at a high speed with my foot completely on the brake almost to the floor. I rammed into the car in front of me and the car flew forward 500 feet. My BMW stopped after it hit the car in front of me. I sat in the car in shock with my foot still on the brake as the driver in front of me came to my window and asked me " what the hell are you doing"? She could clearly see that my foot was still on the brake. There were minor scratches on her bumper and, her and her son had sore necks. The front of my car had a broken grill, and other broken pieces. Broken pieces were lying on thre road. I called AAA and had it towed to BMW in St. Albans, West Virginia. A call was made to Canton, BMW and Corporate BMW to make a report on BMW rapidly accelerating with brakes completely on. Corporate personelle are to call me to get a report from me and send a special team to investigate the "rapid acceleration" while the brakes were on. Now awaiting for the 2015 BMW 328i to be looked at.

NHTSA ODI #11521081

Mileage unknown · Mar 21, 2023
Electrical System

Car isn’t receiving enough power to charge the battery so it’s cutting off while I’m driving

NHTSA ODI #11512925

Mileage unknown · Feb 1, 2023
Unknown Or Other

I was driving this evening and the panoramic sunroof suddenly and unexpectedly shattered. There was no warning or event that led to this. No pothole or external factor. The road was smooth and no other cars were around my vehicle. I heard an extremely loud "pop" and thought something had hit my vehicle. When I stopped to identif…

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I was driving this evening and the panoramic sunroof suddenly and unexpectedly shattered. There was no warning or event that led to this. No pothole or external factor. The road was smooth and no other cars were around my vehicle. I heard an extremely loud "pop" and thought something had hit my vehicle. When I stopped to identify the problem, I exited my vehicle ad saw the panoramic sunroof glass was cracked and shattered, but had lifted up in a domed shape, or a bubble. The outside temperature was about 17 degrees. Fortunately I had the headliner in the closed position so no broken glass would have fallen into the cabin.

NHTSA ODI #11505067

Mileage unknown · Feb 1, 2023
Fuel/propulsion SystemService BrakesUnknown Or OtherCrashInjury

Reporting very dangerous sudden unintended acceleration of 2015 BMW 328i: When about to back out of a parking space in a parking garage, I pressed the brakes and turned on the ignition switch. After looking around to ensure no cars or people were near the car, I put the gear shift in reverse, turned my whole head entirely over m…

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Reporting very dangerous sudden unintended acceleration of 2015 BMW 328i: When about to back out of a parking space in a parking garage, I pressed the brakes and turned on the ignition switch. After looking around to ensure no cars or people were near the car, I put the gear shift in reverse, turned my whole head entirely over my right shoulder to look through the back windshield and, seeing nothing behind me, began to slowly lift my foot from the brake to reverse out of the parking space. I turned the steering wheel towards the left and the back of the car went to the left. The bumper gently tapped a white column that had been out of sight all the way further over my right shoulder. I gently pressed on the brake, and when I switched the gear shift into drive, the car suddenly and explosively accelerated forward extremely fast and sped out of control. I pressed the brakes to stop the car, which did nothing, and the car slammed into cement wall so hard that it sounded like an explosion and the air bags deployed. I hit my mouth/face/head on the air bag and got whiplash from the sudden stop. When I got out of the car, a couple who’d heard the explosion drove by and asked if I was ok. After a few moments I reached into the car to turn off ignition switch. This event resulted in very serious damage to the car, which was totaled, and I received medical injuries. This incident was reported to my automobile insurance company and to North America BMW, who has escalated the report to higher levels due to the seriousness of the incident, and will be doing investigations this week. The accelerator pedal or gear box dangerously and seriously malfunctioned, and the car is available for inspection upon request. My safety was seriously at risk as I have headaches and whiplash symptoms. If there were no wall there, or if there had been people or cars anywhere in front of the car, they would have been killed and smashed because the car suddenly accelerated so quickly.

NHTSA ODI #11504968

Mileage unknown · Jan 26, 2023
Unknown Or Other

I was driving on an interstate highway this afternoon in Houston at approximately 65 mph when the non-panoramic (single window) sunroof of my 2015 BMW 328i exploded over my head. Sounded like a gunshot. Large and small glass shards all throughout the cabin. No other vehicles within particularly close range of my car when it ha…

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I was driving on an interstate highway this afternoon in Houston at approximately 65 mph when the non-panoramic (single window) sunroof of my 2015 BMW 328i exploded over my head. Sounded like a gunshot. Large and small glass shards all throughout the cabin. No other vehicles within particularly close range of my car when it happened. No visible rock or other debris. No sound or vibration from any impact. Appeared to be spontaneous and not the result of rock or debris. Upon inspection from the outside, it appears clear that there was an outward explosion - pictures and video show the glass around the perimeter of the hole angled upward toward the sky. Glass of course showered into the cabin as well. Despite the dispersion of glass within the interior of the cabin, fortunately I did not suffer any cuts or other injury. But the incident was extremely dangerous. The explosion was very loud and could easily cause a driver to become distracted and/or lose control of the vehicle, especially if occurring under heavier traffic conditions. Obviously the risk of a cut and/or injury to the eyes is significant as well. I called a local BMW auto dealership to discuss the issue. The service advisor indicated that he has seen this happen a number of times with BMW vehicles but that BMW will not cover the cost of repair unless the vehicle is still under warranty. Thank you for your time and consideration of this incident.

NHTSA ODI #11503883

Mileage unknown · Sep 13, 2022
Fuel/propulsion System

while im driving at my normal speed about 70mph the car start to get in safe mode, i was on the free way at the time so the car start to stop and lost accerlation, when i checl with my mechanic he told me i need to change the fuel pump and i found out there is a complane "Report Receipt Date: MAR 31, 2015 NHTSA Campaign Number…

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while im driving at my normal speed about 70mph the car start to get in safe mode, i was on the free way at the time so the car start to stop and lost accerlation, when i checl with my mechanic he told me i need to change the fuel pump and i found out there is a complane "Report Receipt Date: MAR 31, 2015 NHTSA Campaign Number: 15V189000 Component(s): FUEL SYSTEM, GASOLINE Potential Number of Units Affected: 18,054" but when i called the dealership they told me im not covered to fix the problem but my car was listed on here" Manufacturer: BMW of North America, LLC SUMMARY: BMW of North America LLC (BMW) is recalling certain model year 2014 228i Coupe, M235i Coupe, 320i, 320xi, 328i, 328xi, 335i, 335xi, ActiveHybrid 3, 328xi Sports Wagon, 428i Coupe, 428xi Coupe, 435i Coupe, 435xi Coupe, 428i Convertible, 428xi Convertible, 435i Convertible, 328xi Gran Turismo, 335xi Gran Turismo, and 2015 428i Gran Coupe, 428xi Gran Coupe, and 435i Gran Coupe vehicles. Improper nickel plating of components within the fuel pump may result in the fuel pump failing.

NHTSA ODI #11484264

Mileage unknown · Sep 5, 2022
Engine

BMW 328I check engine sensor light on code p0281 to replace coolant thermostat. Part has been replaced and code continually appears something’s as ABS CHASIS malfunction sensor or check engine. Code also reads thermostat stuck open.

NHTSA ODI #11482888

Official recalls

4

24V608000 · Electrical System:wiring:connectors/plugs/receptacles; Engine And Engine Cooling:cooling System:pump

Aug 13, 2024

BMW of North America, LLC. (BMW) is recalling certain 2012-2015 X1 sDrive28i, X1 xDrive28i, 2012-2016 Z4 sDrive28i, 528i, 528i xDrive, 328i, 328xi, 2016-2018 X5 xdrive 40e, 2014-2016 228i, 228xi, 428i, 428i xDrive, 328xi Gran Turismo, 2013-2017 X3 sDrive28i, X3 xDrive28i, 2015-2018 X4 xDrive28i, 2015-2016 428xi vehicles. An improperly sealed electrical connector on the water pump may be exposed to water and short circuit.

Consequence & remedy

Consequence: An electrical short increases the risk of a fire.

Remedy: Dealers will inspect and replace the water pump and plug connector as necessary, and install a protective shield, free of charge. Owner notification letters were mailed on March 28, 2025. Owners may contact BMW customer service at 1-800-525-7417.

Additional source detail variants (2)

Electrical System:wiring:connectors/plugs/receptacles

BMW of North America, LLC. (BMW) is recalling certain 2012-2015 X1 sDrive28i, X1 xDrive28i, 2012-2016 Z4 sDrive28i, 528i, 528i xDrive, 328i, 328xi, 2016-2018 X5 xdrive 40e, 2014-2016 228i, 228xi, 428i, 428i xDrive, 328xi Gran Turismo, 2013-2017 X3 sDrive28i, X3 xDrive28i, 2015-2018 X4 xDrive28i, 2015-2016 428xi vehicles. An improperly sealed electrical connector on the water pump may be exposed to water and short circuit.

Consequence: An electrical short increases the risk of a fire.

Remedy: Dealers will inspect and replace the water pump and plug connector as necessary, and install a protective shield, free of charge. Owner notification letters were mailed on March 28, 2025. Owners may contact BMW customer service at 1-800-525-7417.

Engine And Engine Cooling:cooling System:pump

BMW of North America, LLC. (BMW) is recalling certain 2012-2015 X1 sDrive28i, X1 xDrive28i, 2012-2016 Z4 sDrive28i, 528i, 528i xDrive, 328i, 328xi, 2016-2018 X5 xdrive 40e, 2014-2016 228i, 228xi, 428i, 428i xDrive, 328xi Gran Turismo, 2013-2017 X3 sDrive28i, X3 xDrive28i, 2015-2018 X4 xDrive28i, 2015-2016 428xi vehicles. An improperly sealed electrical connector on the water pump may be exposed to water and short circuit.

Consequence: An electrical short increases the risk of a fire.

Remedy: Dealers will inspect and replace the water pump and plug connector as necessary, and install a protective shield, free of charge. Owner notification letters were mailed on March 28, 2025. Owners may contact BMW customer service at 1-800-525-7417.

24V527000 · 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.

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

1

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.