NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
32 reportsClear category filterMileage unknown · Sep 7, 2026
Engine
As noted in my last report that I sent to you now my truck needs an engine because of a road knock. This is the second engine. It was changed in 2011 and I’ve been complaining about this and I wanted Chevy to do a pico test they refused to do it because they’re telling me it’s too old but the truck only 111842 miles on it As pri…
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As noted in my last report that I sent to you now my truck needs an engine because of a road knock. This is the second engine. It was changed in 2011 and I’ve been complaining about this and I wanted Chevy to do a pico test they refused to do it because they’re telling me it’s too old but the truck only 111842 miles on it As prior complaint coming back from Cape May, the truck stalled I toasted to the side and it took a long time for it to start back up and when it did, it started knocking real loud Now Chevy refuses to do anything about this. Maybe I could get some response out of you. Thank you for your help.
NHTSA ODI #11762511
Mileage unknown · Aug 27, 2026
Engine
Driving down the road returning from Cape May on my way back home before I got off the exit at [XXX] the truck shook shimmied and shut off. It took a long time before I could get it to start and when it did start, the motor knocked clanked real loud. And shook real bad. I stopped at the Chevy dealer [XXX] there [XXX] and they sa…
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Driving down the road returning from Cape May on my way back home before I got off the exit at [XXX] the truck shook shimmied and shut off. It took a long time before I could get it to start and when it did start, the motor knocked clanked real loud. And shook real bad. I stopped at the Chevy dealer [XXX] there [XXX] and they said there was nothing wrong with my truck mileage on my truck is111547 I need to remind you that the engine was changed at 10,000 miles INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA ODI #11760010
Mileage unknown · Feb 18, 2026
Engine
For the last couple years, I have been talking to Chevrolet GM. My engine has been replaced at 9000 miles. This motor now does not even have 100,000 miles on it. The second engine left me stranded twice coming back from a long trip. The motor shook stalled and I could not get it. Restarted once I did get it restarted the engine …
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For the last couple years, I have been talking to Chevrolet GM. My engine has been replaced at 9000 miles. This motor now does not even have 100,000 miles on it. The second engine left me stranded twice coming back from a long trip. The motor shook stalled and I could not get it. Restarted once I did get it restarted the engine made a loud banging noise my truck looks practically brand new. It just sits in the driveway and looks pretty. I’m afraid to drive it because it’s gonna leave me stranded again and I have been talking with Chevrolet and he seemed to keep pushing me away and I don’t know what else to do
NHTSA ODI #11718892
Mileage unknown · Apr 20, 2025
Engine
Engine has a loud tapping sound and starting to stumble, have a collapse lifter on a 5.3L. Sell it or trade it in only wanna give me $2500 for due to the engine failure. I’ve maintained this vehicle. I work in the automotive industry change the oil every 5000 miles changed all the fluids spark plugs, brakes tires, no tears no ri…
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Engine has a loud tapping sound and starting to stumble, have a collapse lifter on a 5.3L. Sell it or trade it in only wanna give me $2500 for due to the engine failure. I’ve maintained this vehicle. I work in the automotive industry change the oil every 5000 miles changed all the fluids spark plugs, brakes tires, no tears no rips, immaculate and I have a weight I’ve had it since 2012 or 2013 engine failure is not acceptable well like compensation or have it repaired?
NHTSA ODI #11655674
Mileage unknown · Oct 23, 2024
Electrical SystemEngineStructure
I just bought this truck in June of 2024. This was a bad dealer because he knowingly sold me the truck with severe frame damage and let me drive a dangerous truck off the lot. I cannot deem it as a total loss to have it replaced because it falls under “wear and tear”. I now have to pay for the truck for the next 5 years and don’…
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I just bought this truck in June of 2024. This was a bad dealer because he knowingly sold me the truck with severe frame damage and let me drive a dangerous truck off the lot. I cannot deem it as a total loss to have it replaced because it falls under “wear and tear”. I now have to pay for the truck for the next 5 years and don’t have the money to fix it because the quote states it will be around $13,000, which is how much he sold me the truck for. Because it is a 2010 the warranty has expired. I am completely frustrated and disappointed that there is no one to help me with this betrayal. I have read that many others who have bought GMC’s are and have had the same issues and GM refuses to recall the frames. Something needs to be done about this considering it is GM who did not apply any anti-rust or anti-corrosion to the frames on their vehicles.
NHTSA ODI #11621561
Mileage unknown · Oct 16, 2024
EnginePower Train
GM 3.0 diesel engine has a coolant control valve that fails putting the vehicle into a reduced power mode causing the vehicle to have significantly reduced acceleration and putting the engine fan at full to reduce engine heat. When stopped, the engine had been running very hot as you can hear the popping from the metal as it coo…
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GM 3.0 diesel engine has a coolant control valve that fails putting the vehicle into a reduced power mode causing the vehicle to have significantly reduced acceleration and putting the engine fan at full to reduce engine heat. When stopped, the engine had been running very hot as you can hear the popping from the metal as it cools off. The part to repair this issue is 40009158 and is being replaced by 40009452. This part is on a nationwide backorder with hundreds on the waiting list just at this time for a repair and no clear picture of when parts will become available. Many other cases have been reported since 2021 for the same issue with the 3.0 GM Duramax engine with engine code/styles LM2 & LZO.
NHTSA ODI #11620120
176,300 miles · May 2, 2024
Electrical SystemElectronic Stability Control (esc)Engine
The contact owns a 2010 Chevrolet Silverado 1500. The contact stated that on several occasions while driving at various speeds, the instrument cluster became inoperable, and the vehicle shuddered and stalled. The vehicle was able to restart after 20-seconds on all occasions. The traction control, stabili-trak, and the check engi…
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The contact owns a 2010 Chevrolet Silverado 1500. The contact stated that on several occasions while driving at various speeds, the instrument cluster became inoperable, and the vehicle shuddered and stalled. The vehicle was able to restart after 20-seconds on all occasions. The traction control, stabili-trak, and the check engine warning lights were illuminated. The vehicle was taken to an independent mechanic, but the failure could not be duplicated. The manufacturer was notified of the failure. The failure mileage was 176,300.
NHTSA ODI #11586497
Mileage unknown · Jan 2, 2022
EnginePower Train
Engine oil pressure was critically low. I could not drive the vehicle until I had it repaired.
NHTSA ODI #11445889
100,000 miles · May 17, 2021
Engine
THE CONTACT OWNS A 2010 Chevrolet Silverado 1500. THE CONTACT STATED THAT ENGINE PRESSURE SENSOR SLAVE SWITCH FAILED THREE TIMES. A DEALER WAS NOT CONTACTED. THE FAILURE RECURRED TWO ADDITIONAL TIMES WITH THE CHECK ENGINE WARNING LIGHT ILLUMINATED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE HOWEVER, REFERRED THE CONTACT TO THE…
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THE CONTACT OWNS A 2010 Chevrolet Silverado 1500. THE CONTACT STATED THAT ENGINE PRESSURE SENSOR SLAVE SWITCH FAILED THREE TIMES. A DEALER WAS NOT CONTACTED. THE FAILURE RECURRED TWO ADDITIONAL TIMES WITH THE CHECK ENGINE WARNING LIGHT ILLUMINATED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE HOWEVER, REFERRED THE CONTACT TO THE NHTSA TO FILE A COMPLAINT. THE FAILURE MILEAGE WAS APPROXIMATELY 100,000.
NHTSA ODI #11417515
51,000 miles · Mar 31, 2021
Engine
ENGINE STARTED TICKING NOISE DURING WINTER 2020 AT ABOUT KM 83000. I CHANGED ENGINE OIL. DURING WINTER NO NOISE AT START UP, ONCE THE OPERATING TEMP REACHES 100 * F. TICKING NOISE STARTS. I TOOK IT TO DEALER, TOLD ME LIFTERS, GAVE ME QUOTE FOR CAMSHAFT & LIFTERS, VERY EXPENSIVE. I HEAR THESE ENGINES ARE KNOWN FOR HYDRAULIC LIFT…
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ENGINE STARTED TICKING NOISE DURING WINTER 2020 AT ABOUT KM 83000. I CHANGED ENGINE OIL. DURING WINTER NO NOISE AT START UP, ONCE THE OPERATING TEMP REACHES 100 * F. TICKING NOISE STARTS. I TOOK IT TO DEALER, TOLD ME LIFTERS, GAVE ME QUOTE FOR CAMSHAFT & LIFTERS, VERY EXPENSIVE. I HEAR THESE ENGINES ARE KNOWN FOR HYDRAULIC LIFTER PROBLEMS. I JUST PARKED THE TRUCK AS WINTER SNOW & COLD. OUT OF WARRANTY. MY MILEAGE IS LOW. I CONTACTED GMCANADA, THEY REFER ME BACK TO DEALER. THEN ANOTHER DEALER TOLD ME GET AC DELCO ENGINE OIL SUPPLEMENT, GM PRODUCT. I USED THIS, NO IMPROVEMENT, MORE NOISE, GOT WORSE. I PARKED THE TRUCK DURING WINTER. PLEASE LOOK IN TO THIS. ENGINE NOISE AT AROUND KM 83000 ? I CHANGE ENGINE OIL & FILTER REGULARLY. QUAKER STATE SYNTHETIC ENGINE OIL, I LIVE IN CANADA. I HAVE FAMILY IN USA.
NHTSA ODI #11405710
Official recalls
3Feb 5, 2021
General Motors, LLC (GM) is recalling certain 2007-2011 Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, Yukon XL, and 2009-2011 Chevrolet Silverado 2500, Silverado 3500, GMC Sierra 2500 and Sierra 3500 vehicles originally sold, or ever registered, in the states of Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands or "Zone A." Additionally, GM is recalling certain 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, Yukon XL vehicles originally sold, or ever registered, in the states of Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia or "Zone B." These vehicles are equipped with non-desiccated passenger frontal inflators containing phase-stabilized ammonium nitrate (PSAN) propellant. These inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, high temperatures, and high temperature cycling.
Consequence & remedy
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.
Remedy: GM will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. Interim letters notifying owners of the safety risk were mailed on February 22, 2021. Second notification letters will be mailed once the remedy is available. Owner notification letters were mailed on March 1, 2021. Owners may contact Chevrolet customer service at 1-800-222-1020; Cadillac customer service at 1-800-458-8006; and GMC customer service at 1-800-462-8782. GM's number for this recall is N212328760.
Feb 5, 2021
General Motors, LLC (GM) is recalling certain 2013 Cadillac Escalade, Escalade ESV, and Escalade EXT, Chevrolet Avalanche, Silverado 1500, Silverado 2500/3500, Suburban, Tahoe, GMC Sierra 1500, Sierra 2500/3500, Yukon, and Yukon XL vehicles originally sold, or ever registered, in the states of Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands or "Zone A." Additionally, GM is recalling certain 2010 Cadillac Escalade, Escalade ESV, and Escalade EXT, Chevrolet Avalanche, Silverado 1500, Silverado 2500/3500, Suburban, Tahoe, GMC Sierra 1500, Sierra 2500/3500, Yukon, and Yukon XL vehicles originally sold, or ever registered in the states of Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia or "Zone B." Additionally, GM is recalling certain 2009 Cadillac Escalade, Escalade ESV, and Escalade EXT, Chevrolet Avalanche, Silverado 1500, Silverado 2500/3500, Suburban, Tahoe, GMC Sierra 1500, Sierra 2500/3500, Yukon, and Yukon XL vehicles originally sold, or ever registered, in the states of Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming or "Zone C."
Consequence & remedy
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.
Remedy: GM will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. Interim letters notifying owners of the safety risk were mailed on February 24, 2021. Second notification letters will be mailed once the remedy is available. Owner notification letters were mailed on May 11, 2021. Owners may contact Cadillac customer service at 1-800-458-8006; Chevrolet customer service at 1-800-222-1020; and GMC customer service at 1-800-462-8782. GM's number for this recall is N212328790.
Feb 5, 2021
General Motors, LLC (GM) is recalling certain 2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, and Yukon XL vehicles originally 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 GM is recalling certain 2011-2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, Yukon XL and 2011-2013 Cadillac Escalade EXT, Chevrolet Avalanche, Silverado 1500, and GMC Sierra 1500 vehicles originally sold, or 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." Additionally, GM is recalling certain 2010-2014 Cadillac Escalade, Escalade ESV, Chevrolet Silverado 2500, Silverado 3500, Suburban, Tahoe, GMC Sierra 2500, Sierra 3500, Yukon, and Yukon XL and 2010-2013 Cadillac Escalade EXT, Chevrolet Avalanche, Silverado 1500, and GMC Sierra 1500 vehicles originally sold, or ever registered, in the states of AK, CO, CT, ID, IA, ME, MA, MI, MN, MT, NH, NY, ND, OR, RI, SD, UT, VT, WA, WI, and WY or "Zone C." These vehicles are equipped with non-desiccated passenger frontal inflators containing phase-stabilized ammonium nitrate (PSAN) propellant. These inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, high temperatures, and high temperature cycling.
Consequence & remedy
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants, resulting in serious injury or death.
Remedy: GM will notify owners, and dealers will replace the front passenger air bag inflator with an alternate one, free of charge. Interim letters notifying owners of the safety risk were mailed on February 25, 2021. Second notification letters will be mailed once the remedy is available. Owner notification letters were mailed to 40 VIN owners on May 11, 2021. A second owner notification letter was mailed to all other owners on January 24, 2022. Owners may contact Chevrolet customer service at 1-800-222-1020; Cadillac customer service at 1-800-458-8006; and GMC customer service at 1-800-462-8782. GM's number for this recall is N212328800.
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
2DP22005 · Pedestrian Alert Sounds
Opened Jan 27, 2023 · Closed Aug 7, 2023
Status: closed (inferred from source dates) · Electrical System:propulsion System
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight rating of 4,536 KG or less or are defined as low-speed vehicles. The standard became fully applicable to all such vehicles manufactured on or after March 1, 2021.On January 27, 2023, NHTSA opened Defect Petition (DP) 22-005 to evaluate the subject matter described in the petition. On June 24, 2023 and as supplemented on June 25, 2023, the petitioner notified NHTSA he was withdrawing his petition. The petitioner indicated that, based on his review of data, there is no justification for asserting potential benefits that could be derived from actions sought by my petition. Based on the petitioner's withdrawal, DP22-005 is closed. Closure of this DP does not represent a determination by NHTSA regarding the subject matter of the petition.
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.