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2014 MERCEDES-BENZ C250

Owner reports · Recalls · Investigations

Similar to other model years

Owner complaints for the 2014 MERCEDES-BENZ C250 do not stand out strongly from the model-year median of 163.

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When problems were reported

Mileage at the reported incident

66 reports with mileage · 97 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.

  • Air Bags. Review the 93 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Engine. Review the 22 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
  • Steering. Review the 18 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →

NHTSA owner reports · September 18, 2026 snapshot.

13 crash reports4 fire reports9 injury reports

Steering complaints

18 reports
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Mileage unknown · May 6, 2026
Steering

The electronic steering lock (ESL) system on my 2014 Mercedes-Benz C250 failed without warning, leaving the vehicle completely unable to start. When attempting to start the vehicle, the key would insert but the vehicle would not crank or start, and the steering lock malfunction prevented normal operation of the vehicle. The vehi…

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The electronic steering lock (ESL) system on my 2014 Mercedes-Benz C250 failed without warning, leaving the vehicle completely unable to start. When attempting to start the vehicle, the key would insert but the vehicle would not crank or start, and the steering lock malfunction prevented normal operation of the vehicle. The vehicle became stranded and inoperable. This failure created a safety risk because the vehicle could not be moved and left me stranded unexpectedly. If this failure were to occur in an unsafe area or emergency situation, it could place the driver and passengers at risk. After researching the issue, I found numerous reports online from other owners of similar Mercedes-Benz C-Class models experiencing the same ESL/EIS failure. This appears to be a common issue affecting these vehicles. At this time, the problem has not yet been repaired. UNKNOWN if the manufacturer has inspected the vehicle. No warning lights or prior symptoms appeared before the failure. The malfunction happened suddenly and without warning.

NHTSA ODI #11736140

Mileage unknown · Sep 19, 2025
Steering

The "ESL Module" in this model is designed to unlock the steering and ignition when the vehicle key's passcode matches, using a small, mechanical motor with significantly poor durability. The problem is that this motor's failure is unpredictable, and many users of this model have been stranded and unable to start their vehicles …

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The "ESL Module" in this model is designed to unlock the steering and ignition when the vehicle key's passcode matches, using a small, mechanical motor with significantly poor durability. The problem is that this motor's failure is unpredictable, and many users of this model have been stranded and unable to start their vehicles due to the motor's lifespan ending. Even when the car is painstakingly brought to a dealership, repairs cost approximately $1,800 to $2,000, or owners are resorting to unofficial bypasses using a device called an ESL Emulator from the aftermarket. I'd like to request NHTSA to start a thorough investigation into this issue and a RECALL order for the affected models to be issued to MBUSA. Thank you.

NHTSA ODI #11688424

70,664 miles · Aug 19, 2025
Steering

The contact owns a 2014 Mercedes-Benz C-250. The contact received notification of NHTSA Campaign Number: 17V252000 (STEERING). The contact stated that the recall repair was completed in 2018. The contact stated that the vehicle failed to start. After several attempts, the vehicle failed to start. The contact deactivated the push…

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The contact owns a 2014 Mercedes-Benz C-250. The contact received notification of NHTSA Campaign Number: 17V252000 (STEERING). The contact stated that the recall repair was completed in 2018. The contact stated that the vehicle failed to start. After several attempts, the vehicle failed to start. The contact deactivated the push start button and attempted to start the vehicle with the key whoever, but the vehicle failed to start. The vehicle was towed to the dealer, where it was diagnosed and determined that the steering wheel had seized due to the steering coupling connecting bolt. The vehicle remained at the dealer pending the repair. The manufacturer was made aware of the failure. The contact stated that the manufacturer was contacted prior to the dealer repairing the vehicle in 2018. The contact was advised to take the vehicle back to the dealer, where the repair was completed in 2018, to have the vehicle inspected, and if the part that failed was the part replaced under the recall, the manufacturer would pay for the additional repair. The contact stated that the vehicle was not drivable and that the dealer was three hours away. The failure mileage was approximately 70,664.

NHTSA ODI #11681703

Mileage unknown · Jul 7, 2025
Steering

The ESL has failed and it has happened in a lot of these cars.i was unable to move my steering wheel.

NHTSA ODI #11671505

Mileage unknown · Nov 20, 2024
Electrical SystemSteering

A known issue by many mB owners related to Steering Wheel Lock or ESL system. Car will not start due to a known defect related to a part installed inside the steering wheel preventing owners from starting car safely and to get to destination safely.

NHTSA ODI #11626338

Mileage unknown · Sep 20, 2023
Steering

Mercedes has a convenience easy enter/exit feature that lifts the steering and slides the driver's seat back for easy exit and restores the seat and steering when the driver sits down and places the key in the ignition. The safety issue is the steering often gets locked in the up position and doesn't lower, making it unsafe to …

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Mercedes has a convenience easy enter/exit feature that lifts the steering and slides the driver's seat back for easy exit and restores the seat and steering when the driver sits down and places the key in the ignition. The safety issue is the steering often gets locked in the up position and doesn't lower, making it unsafe to drive the car. This is happened 5 times since I bought the car. I had to drive home with the steering wheel locked above the dashboard. The car has been towed to the dealership 4 times under warranty and now I have to get it towed myself. There are approximately 54000 miles on the car.

NHTSA ODI #11545542

Mileage unknown · Sep 23, 2022
SteeringUnknown Or Other

Steering lock mechanism fails without warning and leaves vehicle and occupants stranded in potentially dangerous location. No onsite repair possible. Vehicle must be towed to authorized dealer for repair. > Safety of car occupants was at risk. > No warning prior to failure. > Repair cost ~!500. Unsure of reliability of repla…

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Steering lock mechanism fails without warning and leaves vehicle and occupants stranded in potentially dangerous location. No onsite repair possible. Vehicle must be towed to authorized dealer for repair. > Safety of car occupants was at risk. > No warning prior to failure. > Repair cost ~!500. Unsure of reliability of replacement unit > My dealer says this is a frequent occurrence. 6+ repairs / month for this model car at this dealer, Expects same frequency at others > Dealer service agent stated he personally believes it should be covered by a recall or free repair. > Filed formal complaint with Company (Mercedes-Benz) but reimbursement was refused. > Similar stranding incident on same car occurred in 05/2021 and car require tow to same dealer who suspected same problem but was unable to duplicate and/or repair the failing component at that time

NHTSA ODI #11486036

Mileage unknown · Jun 20, 2019
Air BagsElectronic Stability Control (esc)Steering

THE AIRBAG LIGHT CAME ON. DASH BOARD DISPLAYS LEFT AIRBAG MALFUNCTION, HORN NO LONGER WORKS, DISPLAY CAN NOT BE CLEARED. STEERING MAKE LOTS OF OF CLICKING SOUND WHEN TURNED ON EITHER DIRECTION. TOOK THE CAR TO THE MERCEDES DEALERSHIP FOR DIAGNOSIS. THE INITIAL RESPONSE WAS THAT THE STEERING MODULE FAILED AND MY ASSESSMENT WAS IT…

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THE AIRBAG LIGHT CAME ON. DASH BOARD DISPLAYS LEFT AIRBAG MALFUNCTION, HORN NO LONGER WORKS, DISPLAY CAN NOT BE CLEARED. STEERING MAKE LOTS OF OF CLICKING SOUND WHEN TURNED ON EITHER DIRECTION. TOOK THE CAR TO THE MERCEDES DEALERSHIP FOR DIAGNOSIS. THE INITIAL RESPONSE WAS THAT THE STEERING MODULE FAILED AND MY ASSESSMENT WAS IT IS PROBABLY DUE TO RECALL NO GROUND WIRE RECALL NUMBER 17V627000.. UPON FURTHER INQUIRY THE DEALER TOLD ME THAT THE STEERING MODULE BROKE AND CAME APART. I SUSPECT THIS EITHER DUE TO DEFECTIVE STEERING MODULE OR RECALL # 17V252000 STEERING BOLT. I HAD COMMUNICATED THIS ISSUE TO MBUSA VIA EMAILS AND SEVERAL PHONE CALLS. THEY STILL HAVEN'T AGREED TO COVER THE COST OF THE REPAIR. AFTER SEVERAL CALLS TO THE DEALER, THEY FINALLY SHARED THE PICTURE OF THE STEERING MODULE AS YOU CAN SEE IT ATTACHED. OTHER OWNERS HAVE REPORTED THE SAME PROBLEM. PLEASE SEE PICTURE OF INSTALLED AND NEW MODULE

NHTSA ODI #11221523

5 miles · Dec 20, 2018
Steering

STEERING WHILE CONDUCTING

NHTSA ODI #11162861

60,000 miles · May 25, 2018
Air BagsSteering

MY STEERING WHEEL STARTED TO CLICK WHEN I TURNED IT, DIDN'T THINK ANYTHING OF IT. I WAS RECENTLY PULLING INTO A PARKING SPOT AND MY STEERING WHEEL MADE A LOUD POP AND GOT STUCK, THEN A LOUD CRACK AGAIN AND STARTED TO WORK. IT STILL CLICKS AND NOW MY PASSENGER AIRBAG LIGHT IS ON PERMANENTLY. I WENT TO THE DEALERSHIP IN OXNARD AND…

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MY STEERING WHEEL STARTED TO CLICK WHEN I TURNED IT, DIDN'T THINK ANYTHING OF IT. I WAS RECENTLY PULLING INTO A PARKING SPOT AND MY STEERING WHEEL MADE A LOUD POP AND GOT STUCK, THEN A LOUD CRACK AGAIN AND STARTED TO WORK. IT STILL CLICKS AND NOW MY PASSENGER AIRBAG LIGHT IS ON PERMANENTLY. I WENT TO THE DEALERSHIP IN OXNARD AND THEY SAID IT WOULD BE 175 TO CHECK ABOUT THE AIRBAGS EVEN THOUGH THERE IS A RECALL. THEY ALSO SAID THEY DON'T HAVE THE PARTS NEEDED TO MY STEERING WHEEL. I DO NOT FEEL SAFE AT ALL DRIVING THIS CAR. THE HORN DOESN'T WORK AND NEITHER DO ANY OF THE BUTTONS ON MY STEERING WHEEL.

NHTSA ODI #11098013

Official recalls

5

21V638000 · Air Bags:frontal

Aug 13, 2021

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2015-2016 E400 Coupe, 2012-2015 C250 Coupe, C350 Coupe, C63 AMG Coupe, 2011-2014 E350 Coupe, and 2012-2014 E350 Cabrio vehicles. An incorrect front passenger air bag may have been installed during a prior repair.

Consequence & remedy

Consequence: An incorrect air bag may not function properly in a crash, increasing the risk of injury.

Remedy: Dealers will replace the front passenger air bag on the affected vehicles, free of charge. Owner notification letters were mailed on September 10, 2021. Owners may contact MBUSA customer service at 1-800-367-6372.

19V787000 · Communication

Nov 1, 2019

Mercedes-Benz USA, LLC. (MBUSA) is recalling certain 2013-2017 vehicles due to a software fault that may cause the date and time for the emergency call system (eCall) to differ from the actual date and time, potentially relaying an inaccurate vehicle location. For a full list of the affected models visit: https://static.nhtsa.gov/odi/rcl/2019/RMISC-19V787-4620.pdf

Consequence & remedy

Consequence: An inaccurate vehicle location may delay emergency responders, increasing the risk of injury.

Remedy: MBUSA has initiated an Over the Air (OTA) remote update. MBUSA will also notify owners, and dealers will check software for a successful OTA or update the communication module software as needed, free of charge. The recall began December 23, 2019. Owners may contact MBUSA customer service at 1-800-367-6372. MBUSA's number for this recall is 2019120008.

19V010000 · Air Bags:frontal:passenger Side:inflator Module

Jan 9, 2019

Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2014 C250, C300 4Matic, C350, C63 AMG, E350 4Matic Coupe, E350 Cabrio, E350 Coupe, SLS AMG Cabrio, SLS AMG Coupe, 2014-2015 C250 Coupe, C350 4Matic Coupe, C350 Coupe, C63 AMG Coupe, GLK 350, GLK250 BlueTec 4Matic, GLK350 RWD, 2015-2017 E400 4Matic Coupe, E400 Cabrio, E400 Coupe, 2014-2017 E550 Cabrio, and 2014-2016 E550 Coupe vehicles sold, or ever registered, in the states of AL, CA, FL, GA, HI, LA, MS, SC, TX, PR, AS, GU, the MP, and VI or "Zone A." Additionally, MBUSA is recalling certain 2012-2014 C250, E350 4Matic Coupe, SLS AMG Cabrio, 2012-2015 C250 Coupe, C350 4Matic Coupe, C350 Coupe, C63 AMG Coupe, 2011 C300, 2011-2014 C300 4Matic, C350, C63 AMG, E350 Cabrio, E350 Coupe, SLS AMG Coupe, 2015-2016 E400 4Matic Coupe, E400 Cabrio, E400 Coupe, 2011-2016 E550 Cabrio, E550 Coupe, 2011-2015 GLK350 4Matic, GLK350 RWD, and 2013-2015 GLK250 BlueTec 4Matic vehicles ever registered in the states of AZ, AR, DE, DC, IL, IN, KS, KY, MD, MO, NE, NV, NJ, NM, NC, OH, OK, PA, TN, VA, and WV or "Zone B." MBUSA is also recalling certain 2012-2014 C250, E350 4Matic Coupe, SLS AMG Cabrio 2012-2015 C250 Coupe, C350 4Matic Coupe, C350 Coupe, C63 AMG Coupe, 2010-2011 C300, 2010-2014 C300 4Matic, C350, C63 AMG, E350 Coupe, 2011-2014 E350 Cabrio, SLS AMG Coupe, 2015-2016 E400 4Matic Coupe, E400 Cabrio, E400 Coupe, 2016-2017 E550 Cabrio, 2010-2016 E550 Coupe, 2010-2015 GLK350 4Matic, GLK350 RWD, and 2013-2015 GLK250 BlueTec 4Matic vehicles ever registered in the states of AK, CO, CT, ID, IA, ME, MA, MI, MN, MO, NH, NY, ND, OR, RI, SD, UT, VT, WA, WI and WY or "Zone C." These vehicles are equipped with air bag inflators assembled as part of the passenger frontal air bag modules that may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, temperature and temperature cycling.

Consequence & remedy

Consequence: An inflator explosion may result in sharp metal fragments striking the passenger or other occupants resulting in serious injury or death.

Remedy: MBUSA will notify owners, and dealers will replace the passenger frontal air bag module, free of charge. The recall began March 29, 2019. Owners may contact MBUSA customer service at 1-800-367-6372.

17V627000 · Air Bags:frontal

Oct 6, 2017

Mercedes-Benz USA, LLC. (MBUSA) is recalling these vehicles: 2014-2018 CLA250, CLA250 4Matic, CLA45 AMG 4Matic, 2015-2018 GLA250, GLA250 4Matic, GLA45 AMG 4Matic, C300 4Matic, C63S AMG, 2012-2014 C250, C350, C300 4Matic, E550 4Matic, 2013-2014 C63 AMG, 2012-2015 C250 Coupe, C350 Coupe, C63 AMG Coupe, 2013-2015 C350 4Matic Coupe, GLK250 4Matic BlueTec, GLK350, GLK350 4Matic, 2016-2017 C350e, C43 AMG, 2015 C400 4Matic, 2016-2018 C63 AMG, GLC300, GLC300 4Matic, 2017-2018 C300 Coupe, C300 4Matic Coupe, C43 AMG, C63 AMG Coupe, C63S AMG Coupe, C300 Cabriolet, C300 4Matic Cabriolet, C43 AMG Cabriolet, C63 AMG Cabriolet, C63S AMG Cabriolet, GLC300 4Matic Coupe, GLC43 AMG, GLC43 AMG Coupe, 2014 E350 Coupe, E350 4Matic Coupe, E350 Cabriolet, E400 Hybrid, 2015-2017 E400 Coupe, E400 4Matic Coupe, E400 Cabriolet, 2014-2017 E550 Coupe, E550 Cabriolet, B250e, 2014-2016 E250 BlueTec, E63 AMG 4Matic Wagon, 2012-2013 E350 BlueTec, 2012-2016 E350, E350 4Matic, 2015-2016 E400, E400 4Matic, 2012 E63 AMG, 2014-2015 E250 4Matic BlueTec, 2013-2016 E350 Wagon, 2017 GLC300d 4Matic, and 2018 GLC350e 4Matic. The driver's air bag may unexpectedly deploy due to insufficient grounding of the steering components if an electrostatic discharge occurs and the air bag clockspring is broken.

Consequence & remedy

Consequence: If the driver air bag inadvertently deploys, it can increase the risk of injury and a crash.

Remedy: MBUSA will notify owners, and dealers will add sufficient grounding to the steering components, free of charge. The recall began in December 6, 2017. Owners may contact MBUSA customer service at 1-877-496-3691.

17V252000 · Steering

Apr 12, 2017

Mercedes-Benz USA LLC. (MBUSA) is recalling certain 2013-2014 C250, C300 4MATIC, GLK250 4MATIC BLUETEC and GLK350 vehicles, 2013 C250 Coupe, C350, C350 4MATIC Coupe, C350 Coupe and C63 AMG Coupe vehicles, and 2013-2015 GLK350 4MATIC vehicles. The steering coupling connecting bolt may have been insufficiently tightened, possibly resulting in a loss of steering.

Consequence & remedy

Consequence: A loss of steering can increase the risk of a crash.

Remedy: MBUSA will notify owners, and dealers will inspect the steering coupling connecting bolt, tightening it as necessary, free of charge. The recall began May 2017. Owners may contact MBUSA customer service at 1-800-367-6372.

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.