NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
621 reportsClear category filterMileage unknown · Nov 27, 2021
Engine
Our car began making noise Wednesday, we took it to mechanic who says there's internal engine knock, and engine may need to be rebuilt or replaced. The issue is consistent with Kia's recent billion-dollar class action settlement, where engines were prone to failure fire. The class action claims window is closed. I don't want …
Read full complaint
Our car began making noise Wednesday, we took it to mechanic who says there's internal engine knock, and engine may need to be rebuilt or replaced. The issue is consistent with Kia's recent billion-dollar class action settlement, where engines were prone to failure fire. The class action claims window is closed. I don't want money, I just want the car fixed. I cannot afford this repair, nor should I have to for a car with under 60k miles. (Kia says it's not under warranty as we're the 2nd owner) I'm looking for any help or guidance for Kia to honor their obligation to repair dangerous vehicles. Please call or email with any feedback if possible - [XXX], [XXX]. Thank you, [XXX] INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6).
NHTSA ODI #11441805
Mileage unknown · Nov 19, 2021
EngineUnknown Or Other
Incident previously reported by telephone to NHTSA agent. On 11/19 while writing report online, [XXX] was accidentally disconnected from Internet at approximately 4:40PM CST. Lengthy comments with details. Can you retrieve? If not and again more briefly, an incident of dangerous unexpected engine shut down and engagement of …
Read full complaint
Incident previously reported by telephone to NHTSA agent. On 11/19 while writing report online, [XXX] was accidentally disconnected from Internet at approximately 4:40PM CST. Lengthy comments with details. Can you retrieve? If not and again more briefly, an incident of dangerous unexpected engine shut down and engagement of limp mode occurred on 9/17/21 while [XXX], son, was traveling at 70-75mph in busy traffic on I-43 just north of Milwaukee. Engine eventually restarted but NO check engine light. Oil level okay. Fuel okay. Still precautionary check by [XXX] for possible engine error codes same day immediately after engine failure (limp mode) at Advance Auto in Manitowoc, WI and NO CODES FOUND. Subsequently NO CODES FOUND by dealer on 10/22/21 I have re-uploaded documents indicating Kia Tech Support states "Do not perform any repairs if the concern cannot be duplicated" and also "see if the customer can duplicate it for you." That is absurd and completely irresponsible nonsense! Customer or other driver should drive at high speeds hoping for engine shut-down? Personal injury? Property damage? Death? INFORMATION Redacted PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). Consumer stated 2015 Kia Optima engine replacement per Kia lifetime warranty on 2/16/22. Vehicle has been diagnoised.
NHTSA ODI #11441080
82,000 miles · Nov 15, 2021
Engine
The contact owns a 2015 Kia Optima. The contact stated while driving 70 MPH, the vehicle stalled without warning. The contact mentioned that the vehicle was in limp mode. The contact attempted to restart the vehicle with the PUSH TO START button however, the vehicle failed to operate. The contact mentioned that there was a waiti…
Read full complaint
The contact owns a 2015 Kia Optima. The contact stated while driving 70 MPH, the vehicle stalled without warning. The contact mentioned that the vehicle was in limp mode. The contact attempted to restart the vehicle with the PUSH TO START button however, the vehicle failed to operate. The contact mentioned that there was a waiting period before being able to restart the vehicle. The vehicle was taken to an independent mechanic where the failure was undetermined. The vehicle was taken to the dealer where the failure was undetermined. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 82,000. Engine has been replaced. At time of the incident on 9/17/21, no DTC code was registered.
NHTSA ODI #11440443
90,423 miles · Nov 12, 2021
Engine
The contact owns a 2015 Kia Optima. The contact stated while driving 70 MPH, the vehicle stalled without warning. The contact was able to coast the vehicle to the shoulder of the road after the failure. Due to the failure, the contact had the vehicle towed to the dealer. The contact was then informed by the dealer that the engin…
Read full complaint
The contact owns a 2015 Kia Optima. The contact stated while driving 70 MPH, the vehicle stalled without warning. The contact was able to coast the vehicle to the shoulder of the road after the failure. Due to the failure, the contact had the vehicle towed to the dealer. The contact was then informed by the dealer that the engine had locked up and needed to be replaced. The dealer contacted the manufacturer and she was informed that since an engine software update was not performed on the vehicle, they would not assist with the repair of the vehicle. The contact spoke directly to the manufacturer and the manufacturer again declined to assist. The vehicle was not repaired and remained in the possession of the dealer. The failure mileage was 90,423.
NHTSA ODI #11440224
53,000 miles · Oct 27, 2021
Engine
The contact owns a 2015 Kia Optima. The contact’s dad stated that while driving approximately 65 MPH, there was an abnormal sound coming from the engine compartment. The contact stated that the check engine warning light was illuminated. The contact pulled over and had the vehicle towed to a local dealer where it was diagnosed w…
Read full complaint
The contact owns a 2015 Kia Optima. The contact’s dad stated that while driving approximately 65 MPH, there was an abnormal sound coming from the engine compartment. The contact stated that the check engine warning light was illuminated. The contact pulled over and had the vehicle towed to a local dealer where it was diagnosed with needing the starter replaced. The vehicle was repaired but continued to experience failure. The manufacturer was informed of the failure and informed the contact that the VIN was not under a recall for the starter. The failure mileage was approximately 53,000.
NHTSA ODI #11438351
122,000 miles · Oct 4, 2021
Engine
The contact owns a 2015 Kia Optima. The contact stated that while his wife was driving at an undisclosed speed, the vehicle came to a complete stop at a stop sign and loss motive power. The contact towed the vehicle to his residence. The contact who works as an independent mechanic, self-diagnosed the failure as the engine seize…
Read full complaint
The contact owns a 2015 Kia Optima. The contact stated that while his wife was driving at an undisclosed speed, the vehicle came to a complete stop at a stop sign and loss motive power. The contact towed the vehicle to his residence. The contact who works as an independent mechanic, self-diagnosed the failure as the engine seized and was not moving with the crankshaft. There was no metal found in the oil or oil filter. The dealer was made aware of the failure and informed the contact there were no recalls associated with the VIN. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 122,000.
NHTSA ODI #11435435
Mileage unknown · Sep 29, 2021
Engine
There has never been any problems with the vehicle. No clicking no lights . I took it before time for an oil change and tune up. The car just stopped at the red light . I had it towed to Kia. It’s been there now a week shy of 2 months. I have to call for updates no one would call me back. I called kia recall department. A lady…
Read full complaint
There has never been any problems with the vehicle. No clicking no lights . I took it before time for an oil change and tune up. The car just stopped at the red light . I had it towed to Kia. It’s been there now a week shy of 2 months. I have to call for updates no one would call me back. I called kia recall department. A lady told me car has 2 recalls on it but they will NOT FIX IT due the time me no having warranty!
NHTSA ODI #11434903
Mileage unknown · Sep 25, 2021
EngineUnknown Or Other
I was driving my car and was hearing a clicking/thumping sound, until I turned left into a street where the motor just started shaking and making a louder noise. I started to press on the brakes because the sound and feeling of the car was very unusual. I came to a complete stop and put my car in park and waited where finally th…
Read full complaint
I was driving my car and was hearing a clicking/thumping sound, until I turned left into a street where the motor just started shaking and making a louder noise. I started to press on the brakes because the sound and feeling of the car was very unusual. I came to a complete stop and put my car in park and waited where finally the engine just cut off even though the lights stayed on. I turned my key back to turn of the car and tried to turn it back on but my motor would just shake and my car would not turn on. i stepped outside and noticed there was oil spilling from under my car. I got it towed to a mechanic where they informed me my rod bearing came lose and punctured a hole in my engine. I called the KIA assistance center and said this was due to the recall SC212, but when i called a KIA dealership they said they could not cover the damage. Turns out this issue was part of a product improvement campaign which KIA would update the ECU in my vehicle.
NHTSA ODI #11434325
60,000 miles · Sep 23, 2021
Engine
The contact owns a 2015 Kia Optima. The contact had initially taken his vehicle to a local dealer to be serviced under NHTSA Campaign Number: 21V331000 (Service Brakes, Hydraulic). Upon return of the vehicle, the contact stated that the vehicle failed to start up after multiple attempts. The contact then took the vehicle to an i…
Read full complaint
The contact owns a 2015 Kia Optima. The contact had initially taken his vehicle to a local dealer to be serviced under NHTSA Campaign Number: 21V331000 (Service Brakes, Hydraulic). Upon return of the vehicle, the contact stated that the vehicle failed to start up after multiple attempts. The contact then took the vehicle to an independent mechanic where the alternator was replaced. The independent mechanic also informed him that the battery would charge to full capacity and referred him back to the dealer. The vehicle was towed to the dealer, but the dealer could not find a failure after an inspection. After a few weeks, the contact stated that the failure returned as the ABS warning light illuminated on the instrument panel. The contact also stated that while his son was driving at 50 MPH, the vehicle stalled while on the highway. The contact was able to restart the vehicle and had the battery checked by another independent mechanic. The contact’s son was informed that the battery was not linked to the failure. The contact’s wife had called the manufacturer and filed a complaint. The vehicle has been repaired. The failure mileage was approximately 60,000. The VIN was not available. Consumer would like to withdraw the complaint since it has been repaired.
NHTSA ODI #11434111
Mileage unknown · Sep 19, 2021
Engine
I was driving on the highway going about 55 miles per hour when suddenly the dashboard lights illuminated and car seemed to power down quickly. I barely had time to pull over to the shoulder of the road when the car completely shut down. I could not get the car to start backup and I had to call a towing company to the scene to t…
Read full complaint
I was driving on the highway going about 55 miles per hour when suddenly the dashboard lights illuminated and car seemed to power down quickly. I barely had time to pull over to the shoulder of the road when the car completely shut down. I could not get the car to start backup and I had to call a towing company to the scene to tow the car to the Kia dealership. My safety and the other occupants safety were put in grave danger, especially driving on a highway where the speed limit is minimum 55 miles per hour. The car dealership confirmed the problem with me, but there is a significant wait time of 2 weeks or more before they can begin performing necessary repairs to the vehicle. Their excuse was an abnormally high number of other Kia Optimas ahead of my vehicle, waiting on parts from Korea, and the warehouse being backup due to the parts shortage. There were no warning lamps or noises prior to the car completely shutting down while driving 55 miles per hour on the highway. It was sudden and caught me off guard and I tried not to panic during the entire dangerous and scary situation. I have been without a replacement vehicle for over two weeks because you cannot get the rental/loaner coverage until the car has been formally diagnosed by a technician. I am paying out-of-pocket until I get the rental car coverage that Kia told me I would qualify for once the car is officially diagnosed and a timeframe is given for estimated date of full repair and pick up of the vehicle.
NHTSA ODI #11433550
Official recalls
4Sep 25, 2023
Kia America, Inc. (Kia) is recalling certain 2010-2019 Borrego, 2014-2016 Cadenza, 2010-2013 Forte, Forte Koup, Sportage, 2015-2018 K900, 2011-2015 Optima, 2011-2013 Optima Hybrid, Soul, 2012-2017 Rio, 2011-2014 Sorento, and 2010-2011 Rondo vehicles. The Hydraulic Electronic Control Unit (HECU) may experience an electrical short, which can result in an engine compartment fire while parked or driving.
Consequence & remedy
Consequence: An engine compartment fire while parked or driving can increase the risk of injury.
Remedy: Owners are advised to park outside and away from structures until the recall repair is complete. Dealers will replace the HECU fuse, free of charge. Interim notification letters, notifying owners of the safety risk, were mailed November 14, 2023. Owner notification letters were mailed March 29, 2024 through June 18, 2024. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC284.
May 10, 2021
Kia Motors America (Kia) is recalling certain 2013-2015 Optima and 2014-2015 Sorento vehicles previously recalled under recall 20V-519. Brake fluid may leak inside the Hydraulic Electronic Control Unit (HECU), possibly resulting in an electrical short.
Consequence & remedy
Consequence: An electrical short in the HECU increases the risk of a fire while parked or driving.
Remedy: Owners are advised to park outside and away from other vehicles and structures until the recall repair is completed. Dealers will install a new multi-fuse, and inspect the HECU for leaks, replacing the HECU if necessary, free of charge. Owner notification letters were mailed on July 2, 2021. This recall supersedes previous NHTSA recall number 20V-519. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC212.
Aug 27, 2020
Kia Motors America (Kia) is recalling certain 2013-2015 Optima and 2014-2015 Sorento vehicles. Brake fluid may leak inside the Hydraulic Electronic Control Unit (HECU), possibly resulting in an electrical short.
Consequence & remedy
Consequence: If the HECU short circuits, there is an increased risk of an engine compartment fire.
Remedy: Kia will notify owners, and dealers will inspect the HECU for leaking brake fluid and replace the HECU if necessary, free of charge. Owners are advised to park outside and away from other vehicles and structures until the recall repair is completed. The recall began October 20, 2020. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC197.
Dec 19, 2018
Kia Motors America (Kia) is recalling certain 2011-2017 Optima, 2012-2017 Sorento and 2011-2018 Sportage vehicles that previously received an engine replacement under recall number 17V-224, warranty, or the Knock Sensor Detection System (KSDS) Product Improvement Campaign. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned or improperly torqued during the engine replacement procedure, possibly causing a fuel leak.
Consequence & remedy
Consequence: A fuel leak in the presence of an ignition source can increase the risk of a fire.
Remedy: Kia has notified owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began January 17, 2019. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC172.
Additional source detail variants (2)
Engine
Kia Motors America (Kia) is recalling certain 2011-2017 Optima, 2012-2017 Sorento and 2011-2018 Sportage vehicles that previously received an engine replacement under recall number 17V-224, warranty, or the Knock Sensor Detection System (KSDS) Product Improvement Campaign. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned or improperly torqued during the engine replacement procedure, possibly causing a fuel leak.
Consequence: A fuel leak in the presence of an ignition source can increase the risk of a fire.
Remedy: Kia has notified owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began January 17, 2019. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC172.
Fuel System, Gasoline:delivery:hoses, Lines/piping, And Fittings
Kia Motors America (Kia) is recalling certain 2011-2017 Optima, 2012-2017 Sorento and 2011-2018 Sportage vehicles that previously received an engine replacement under recall number 17V-224, warranty, or the Knock Sensor Detection System (KSDS) Product Improvement Campaign. The high pressure fuel pipe that connects to the fuel pump outlet may have been damaged, misaligned or improperly torqued during the engine replacement procedure, possibly causing a fuel leak.
Consequence: A fuel leak in the presence of an ignition source can increase the risk of a fire.
Remedy: Kia has notified owners, and dealers will inspect and replace the fuel pipe, as necessary, free of charge. The recall began January 17, 2019. Owners may contact Kia customer service at 1-800-333-4542. Kia's number for this recall is SC172.
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
4AQ23002 · Hyundai And Kia Abs Module Fires
Opened Nov 17, 2023 · No close date supplied
Status: open (inferred from source dates) · Service Brakes, Hydraulic:antilock/traction Control/electronic Limited Slip:control Unit/module
The Office of Defects Investigation (ODI) has received eight Hyundai Motor America (Hyundai) and eight Kia America, Inc. (Kia) Part 573 Recall Reports between 2016 and 2023. The combined 16 safety recalls all involve the antilock braking system (ABS) modules or Hydraulic Electronic Control Units (HECU) manufactured by the equipment supplier Mando. The Part 573 Recall Reports contain varying defect descriptions and differing remedy descriptions for the same or similar equipment supplied by Mando. Safety recalls included in this Audit Query (AQ) review include: Hyundai recalls 20V-520, 20V-543, 21V-161, 21V-160, 21V-303, 22V-056, 22V-810, and 23V-651. Kia recalls 16V-815, 20V-518, 20V-519, 21V-137, 21V-331, 22V-051, 22V-800, and 23V-652 The purpose of this AQ is to evaluate the timeliness and scoping of Hyundai and Kia’s defect decision making and adherence with reporting requirements; and understand the varying defect descriptions and remedies between these recalls.
DP22003 · Loss Of Motive Power
Opened Sep 12, 2022 · Closed Dec 12, 2023
Status: closed (inferred from source dates) · Engine
The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complaints were provided which alleged that the oil drain pans lack sufficient structural integrity and are susceptible to cracking. The petition itself can be reviewed at NHTSA.gov under ODI number 11481745. On September 12, 2022, the Office of Defects Investigation (ODI) opened Defect Petition (DP22-003) to evaluate the Petitioners’ request. The Petitioners have provided additional complaints within four supplemental letters dated January 31, 2023, March 21, 2023, May 23, 2023, and August 4, 2023. ODI’s evaluation included the review and analysis of the complaints and supporting information submitted by the Petitioners, as well as additional complaints submitted directly to NHTSA which referenced either the oil drain plug or a crack in the oil pan. After reviewing the available data, ODI has not identified evidence that would support opening a defect investigation into the oil drain pan assemblies of the subject vehicles. Based on a review of the available information, a loss of motive power resulting from an oil drain plug back out has not occurred between the initial sale of a vehicle and the completion of its first oil change. If during an oil change service, a technician fails to remove the existing drain plug gasket before installing a new gasket, it is likely that a proper seal between the drain plug and the oil pan will not be made. An improper seal between the drain plug and oil pan could lead to the backing out on the drain plug, resulting in the sudden loss of oil while driving. Additionally, the provided examples of oil pan cracks were localized to the immediate vicinity of the oil drain plug and/or appeared to be the result of direct-contact with a tool during servicing. There is no information to support that a vehicle-based defect exists relating to the oil pan assembly, and instead the documented incidents are related to the failure to follow the proper maintenance procedures during oil change service. In October 2023, Hyundai published a Technical Service Bulletin (TSB) that provided detailed instructions for oil change service on its gasoline powered vehicles, specifically highlighting the need to remove and replace the existing drain plug gasket prior to reinstalling the drain plug. After a thorough review of the material submitted by the petitioner, the information already in NHTSA's possession, and the potential risks to motor vehicle safety implicated by the petitioners' allegations, NHTSA does not believe that a formal investigation is warranted. Therefore, the petition is denied. A Federal Register Notice (FRN) further detailing NHTSA’s reasons for denial of the petition will be published. The reference numbers for the complaints to NHTSA cited by the petitioner can be found in the petition submission documents in the public file for DP22-003. To review those complaints and the additional complaints ODI added to its evaluation which are cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.
DP21003 · Throttle Control System Vulnerabilities
Opened Nov 12, 2021 · Closed Jun 20, 2023
Status: closed (inferred from source dates) · Vehicle Speed Control:throttle
The Office of Defects Investigation (ODI) of the National Highway Traffic Safety Administration (NHTSA) received a petition letter dated October 10, 2021, requesting an investigation of possible defects in the electronic throttle control (ETC) system on certain Kia vehicles resulting in the opening of DP21-003. Accordingly, Model Year (MY) 2005-2016 Kia Optima/K5, MY 2006-2015 Kia Sorento, MY 2007-2016 Hyundai Elantra, MY 2007-2016 Hyundai Santa Fe, MY 2006-2015 Hyundai Sonatas are all part of the subject population. The petition was originally filed as a Vehicle Owner Questionnaire that can be reviewed at NHTSA.gov under reference (ODI) number 11439675.On November 12, 2021, ODI opened Defect Petition DP21-003 to evaluate the petitioner?s request. ODI performed trend analyses of the VOQs related to vehicle speed control issues for all the subject vehicles and found that none of the 52 Model/Model Year Hyundai/Kia vehicles demonstrated any actionable trend that warranted an investigation.Petitioners submitted 1119 VOQs and non-VOQ cases in which sudden uncommanded acceleration (SUA) or loss of motive power (LOMP) incidents were alleged.For the 1119 reports, 220 were incidents involving crashes, from which 69 subject Hyundai-Kia vehicles were inspected by Hyundai/Kia dealer technicians, Hyundai/Kia engineers, and/or third-party representatives.ODI found the inspections identified no vehicle defects related to the ETC system.Of the 220 crash-involved reports, 13 Event Data Recorder (EDR) records were downloaded successfully and 11 of those indicated driver error: (i.e.) pedal misapplication.A condition where the accelerator pedal is mistakenly applied instead of the brake pedal when the driver wants to stop the vehicle.In addition, ODI reviewed a scientific journal paper published in Forensic Science International in 2016 by Mr. Park et al ., as well as related test videos. ODI does not believe there is any evidence of uncontrollable SUA occurrences in any of the tests reviewed. NHTSA's Office of Vehicle Safety Compliance (OVSC) reviewed the allegations regarding the potential noncompliance with Federal Motor Vehicle Safety Standard No. 124.Based on the information provided, the Agency concludes there is insufficient information for us to determine if a possible non-compliance exists.Finally, both Hyundai and Kia informed ODI that all their vehicles manufactured after 2012 were equipped with an ETC management system, in which the engine speed will go to idle when the system sees signals from both the brake pedal and accelerator pedal at the same time; this is commonly known as the brake-throttle override system.After thoroughly assessing the material submitted by the petitioner, information already in NHTSA's possession, information submitted by Hyundai and Kia in response to an Information Request letter, and the potential risks to safety implicated by the petitioner's allegation, NHTSA does not believe that a formal investigation is warranted. After full consideration of appropriate factors, the petition is denied. A Federal Register Notice (FRN) further detailing NHTSA?s reasons for denial of the petition will be published.
EA19001 · Electrical Overstress
Opened Apr 19, 2019 · Closed Sep 19, 2024
Status: closed (inferred from source dates) · Air Bags: Air Bag/restraint Control Module
The Office of Defects Investigation (ODI) opened this investigation to determine if the failure of airbags to deploy during severe crashes, in certain vehicles, was the result of a safety related defect. During the investigation a complex failure was studied that can result in non-deployment of subject vehicle air bags and other restraint system devices in severe crash events. The subject vehicles may be equipped with an airbag control unit (ACU) for the supplemental restraint system (SRS) Electronic Control Unit (ECU) manufactured by ZF-TRW. The ECU receives signals from crash sensors mounted in the vehicle and deploys the vehicle air bags and seat belt pretensioners in accordance with manufacturer design specifications. The ECU in the subject vehicles contains a model DS84 application-specific integrated circuit (ASIC) which controls the communication of the crash sensor signal, firing commands (i.e., when to deploy the airbag(s) and/or pretensioners), and fault information (e.g., diagnostic trouble codes). In September 2016, FCA announced recall 16V-668 for certain model year (MY) 2010 to 2014 Chrysler, Dodge and Jeep products manufactured with the subject ZF-TRW ACU. In this recall, FCA discussed an EOS condition that resulted in a failure of the subject DS84 ASIC, which caused air bag non-deployment. FCA noted that the defect condition had only been observed in vehicles equipped with sensor harnessing routed across the front of the vehicle. Other FCA vehicles that also used the subject ACU, but were not equipped with cross-car harnessing, had not experienced EOS failures, despite similar time in service. During the course of this investigation, ODI sent two separate Information Request (IR) letters to six vehicle manufactures (including FCA, Hyundai, Honda, Kia, Mitsubishi, and Toyota) and one IR letter to ZF-TRW. These IR letters resulted in ODI receiving comprehensive data from these manufacturers and suppliers. Studies of this data found that the DS84 ASIC does not have sufficient protection against negative electrical transients or electrical overstress (“EOS”) that can be generated in certain severe crashes. An electrical transient occurs when the electrical power supplied to a circuit changes momentarily over a short duration of time. In these severe crash cases, the crash sensors and other powered wiring can be damaged and short circuited so as to create a negative electrical transient of sufficient intensity and duration (that are outside the vehicle manufacturer's specification) to damage the ASIC before the restraint device deployment signal is received by the SRS ECU. This damaged signal can lead to incomplete or nondeployment of the air bags and/or pretensioners. Airbag non-deployment and/or lack of pretensioner operation can increase the risk or severity of injury in a crash.A total of 8 fatalities and 14 injuries were associated with known EOS events. The common element in all investigated manufacturers vehicles is the SRS ECU containing a DS84 ASIC manufactured by ZF-TRW. The risk associated with the ASIC is equally shared among all OEMS involved in the investigation. The actual real-world risk can be mitigated by other factors which were assessed by ODI during this investigation. The first mitigating factor involves protections built into the ACU design which protect the DS84 ASIC from damage. There are multiple strategies and levels of protection employed by different OEMs that provide effective EOS mitigation. The two most common strategies at the ACU level are circuit protection diodes on the remote senor signal lines, and current limiting resistors that protect critical components. The second mitigating factor is found at the vehicle level and involves the location and routing of the wires leading from the crash sensors to the SRS ECU. If the wires are well protected in a crash and are not routed with other power wires carrying large currents, the risk for an EOS event is significantly reduced or eliminated. These design specific factors combine to produce a spectrum of risk for the vehicles equipped with ACUs using the DS84 ASIC. Given the many of years of field exposure, it is possible to divide the subject population into two groups; vehicles which have experienced EOS events, and vehicles which have not experienced EOS field events. Four of the six OEMs involved in this investigation have experienced EOS field events on at least one of their models equipped with a DS84 ASIC. All vehicle models (including the Toyota models identified in the Failure Report Summary of the opening resume for this investigation) with field events have been recalled. In an abundance of caution, ODI kept this investigation open five years to monitor field performance and did not identify any field events on vehicles not included in existing safety recalls. Given the spectrum of risk identified in this investigation and that all vehicles with a demonstrated unreasonable risk have been recalled, ODI is closing this investigation. ODI is closing this investigation with the following manufacturer safety recalls: 16V-668, 18E-043, 18V-137, 18V-363, and 20V-024. With the recall actions taken by the subject vehicle and equipment manufacturers, this investigation is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exists on other model or model year vehicles outside of the recall scopes. The agency reserves the right to take further action if warranted by the circumstances.