The National Highway Traffic Safety Administration published a notice on June 18, 2026 at 91 FR 36941 setting forth the reasons it denied a motor vehicle defect petition designated DP21-003. The notice, issued under Docket No. NHTSA-2026-1387 by the agency's Office of Defects Investigation (ODI), addresses a petition submitted on October 10, 2021 by Mr. Tom Murray of Huron, Ohio and Mr. Byron Bloch of Potomac, Maryland, and amended on August 5, 2022. The petitioners asked NHTSA to conduct a formal investigation of alleged safety-related defects in dozens of Kia and Hyundai vehicles.

According to the notice, the petition alleged what the document calls an excessive number of vehicle speed control issues and runaway throttle incidents, and asserted that the vehicles' Electronic Throttle Control (ETC) systems were the primary source of the alleged conditions. The petitioners also alleged that certain Model Year 2005-2016 Hyundai and Kia vehicles did not fully comply with Federal Motor Vehicle Safety Standard No. 124, Accelerator Control Systems. The original and amended petitions together identified 52 Hyundai and Kia models and model years, which the agency states it estimates encompasses approximately 6 million vehicles.

"After examination of the amended petition and available data relating to vehicle speed control performance of the subject vehicles, and review of FMVSS No. 124, NHTSA concluded that an investigation is not warranted. The Agency accordingly denied the petition."— Federal Register, source

What the agency's technical review states

The notice describes the analysis ODI conducted in reaching its conclusion. The agency states that it reviewed loss-of-motive-power (LOMP) allegations and reported that of 597 LOMP reports, seven involved alleged crashes, and that ODI found no defect trend in the allegations of LOMP resulting from ETC malfunction for any of the 52 model and model-year combinations. The notice also references prior ODI investigations into loss of motive power or non-crash engine fires on certain subject vehicles, identified as Investigation Nos. RQ17-003, RQ17-004, PE19-003, and PE19-004, and states that those investigations identified no defect trend in the ETC system as the cause.

On the individual crash cases the petition cited, the notice states that four subject vehicles were inspected by dealer technicians, manufacturer engineers, and third-party representatives, and that ODI found no indication of vehicle defects related to the ETC system. The document reports that one event data recorder (EDR) record was downloaded and indicated the root cause of the alleged sudden unintended acceleration to be pedal misapplication, and that a separate vehicle's EDR data evaluated by a team of public-sector experts in South Korea likewise indicated pedal misapplication as the root cause.

The journal paper and the FMVSS No. 124 question

The notice also addresses a scientific journal paper the petitioners cited, published in Forensic Science International in 2016 by Mr. Park and colleagues. According to the agency, the test setup in that paper replaced the vehicle's 12-volt battery with a programmable test battery and changed the power supply from 12 volts to a fluctuating pattern ranging from 7 volts to 14 volts over an 8.8-second cycle. ODI states it believes this power-supply modification does not represent a real-world condition. The notice reports that in two road-test videos reviewed, wide-open throttle was achieved using the modified setup, but that when the accelerator pedal was released the throttle decreased and when the brake was applied the vehicle slowed rapidly. ODI states it does not believe there is evidence of uncontrollable sudden unintended acceleration in the tests reviewed.

On the compliance allegation, the notice states that NHTSA's Office of Vehicle Safety Compliance reviewed the FMVSS No. 124 claim and that the petitioners provided only conclusory information tied to the assertion that sudden unintended acceleration was occurring. The agency concluded there was insufficient information to warrant investigating a potential noncompliance. The notice adds a procedural detail in a footnote: NHTSA states it denied the petition on June 20, 2023, and that publication of the Federal Register notice further detailing the reasons was inadvertently delayed until this June 2026 publication.

The notice states that the denial does not foreclose the agency from taking further action if warranted, or from a future finding that a safety-related defect or noncompliance exists based on additional information the agency may receive. The action was signed by Eileen Sullivan, Associate Administrator for Enforcement, under authority of 49 U.S.C. 30162(d) and 49 CFR part 552.

How the petition process works and what the scope figures show

The notice sets out the statutory framework under which the petition was reviewed. It explains that interested persons may petition NHTSA to initiate an investigation into whether a motor vehicle or item of replacement equipment fails to comply with a safety standard or contains a safety-related defect, citing 49 U.S.C. 30162(a)(2) and 49 CFR 552.1. Upon receiving a properly filed petition, the agency conducts a technical review that may analyze the submitted material and additional information, and may collect information from the manufacturer or other sources. The notice states that in deciding whether to grant or deny, the agency weighs factors that may include the nature of the issue, the allocation of agency resources, agency priorities, the likelihood of uncovering sufficient evidence to establish a defect, and the likelihood of success in any necessary enforcement litigation.

The scope of the petition, as recorded in the notice, was broad. The subject-vehicle list spans model years from 2004 to 2022 and covers nameplates including the Kia Optima/K5, Sorento, Sportage, Sedona, Soul, Forte, Telluride and Niro, and the Hyundai Elantra, Sonata, Santa Fe, Tucson, Palisade, Azera/Grandeur, Genesis G80, and Ioniq/Ioniq 5. The petitioners alleged that the manufacturers had failed to meet U.S. regulatory obligations, including 49 CFR 573.6, which requires manufacturers to report safety defects and noncompliances to NHTSA. The notice records that the petitioners requested a comprehensive evaluation, technical review, engineering analysis, and formal investigation of the alleged defects.

The agency's read on the underlying claim centered on the distinction between a vehicle defect and pedal misapplication. Across the inspected crash cases and the EDR records described in the notice, the agency reports that the data it examined pointed to pedal misapplication rather than an ETC-system defect, and that the journal-paper tests it reviewed did not demonstrate uncontrollable acceleration under conditions ODI considered representative of real-world operation. The full text of the notice, including the model list, the LOMP figures, and the agency's findings quoted above, is available at the Federal Register's canonical document URL.