The Office of Defects Investigations (ODI) is an office within the NHTSA which investigates serious safety problems in the design, construction or performance of vehicles. The NHTSA is authorized to order manufacturers to recall and repair vehicles, if the ODI finds a safety issue. NHTSA investigations for the 2016 Hyundai Sonata, both ongoing and closed, are listed below:

  1. INVESTIGATION: Air Bag ACU Electrical Overstress

    NHTSA Engineering Analysis #EA19001

    • Status:
    • Date Opened: April 19, 2019
    • Date Closed: N/A
    • Recall: No recall yet

    Component(s): Air Bags: Air Bag Control Module

    Summary: The Office of Defects Investigation (ODI) is expanding the investigation to include the equipment supplier and vehicle manufacturers (OEMs) using this unit.The investigation focuses on ACUs manufactured by TRW, now ZF-TRW (ZF), the Tier-one supplier to Hyundai and Kia and the other affected OEMs.The ACU senses a vehicle crash to determine whether air bag deployment is required, and if so, deploys the appropriate air bags and other supplemental restraints.ZF supplied subject ACUs to six OEMs: FCA, Honda, Hyundai, Kia, Mitsubishi and Toyota.Internal to the ACU is an electronic component (an application specific integrated circuit, or ASIC) that monitors signals from crash sensors.A failure of the ASIC may prevent deployment of the required air bags and devices, or may otherwise affect the proper operation of the ACU.The ACU is located in the passenger compartment, and electrical wiring connects the ASIC to sensors located at the front of the vehicle.ODI-s current understanding is that a crash event may, in and of itself, produce harmful signals on the sensor wiring capable of damaging the ASIC, although the probability of this occurring appears to be low.While the ACU incorporates electrical circuitry intended to protect the ASIC from harmful signals, the level and effectiveness of the protective circuitry varies by OEM customer.During PE18-003, Hyundai and Kia filed recalls (18V-137 and 18V-363 respectively) to address a defect that could result in ACU disablement and non-deployments.According to the filings, the disablement occurs in certain types of frontal crash events.Both filings discussed a condition known as electrical overstress (EOS) that affected the subject ASIC and was likely caused by electrical signals that entered the ACU via sensor wiring.The recalled vehicles used ACUs that had the lowest levels of ASIC protection while non-recalled Hyundai and Kia products using subject ACUs had higher levels of protection.ODI has not identified any EOS failures in the non-recalled Kia and Hyundai populations.In September 2016, FCA filed recall 16V-668 for certain model year (MY) 2010 to 2014 Chrysler, Dodge and Jeep products also manufactured with the subject ACU.In that filing, FCA also discussed an EOS condition that resulted in a failure of the subject 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 not the cross-car harnessing, had not experienced EOS failures, despite similar time in service. The recalled FCA vehicles used a mid-level form of ASIC protection.Other FCA vehicles that did not use cross car wiring, or used higher levels of ASIC protection, have not been recalled.ODI has not identified any EOS failures in the non-recalled FCA population.Recently, ODI has identified two substantial frontal crash events (one fatal) involving Toyota products where EOS is suspected as the likely cause of the non-deployments.The crashes involved a MY 2018 and a MY 2019 Corolla equipped with the subject ACU that incorporated higher levels of ASIC protection.Additionally, both ACUs were found to be non-communicative (meaning the ACU could not be read with an Event Data Recorder) after the crash, a condition found in other cases where EOS occurred with other OEMs.No other EOS events have been identified for other Toyota products (including Corolla models that used the subject ACU since MY 2011), or for the Honda and Mitsubishi vehicles that use the subject ACU.ODI plans to evaluate the susceptibility of the subject ACU designs to electrical signals, as well as other vehicle factors that can either lead to, or reduce the likelihood of, an EOS event.Additionally, ODI will evaluate whether an unreasonable risk exists that requires further field action.

  2. INVESTIGATION: Electronic Parking Brake

    NHTSA Preliminary Evaluation #PE16010

    • Status:
    • Date Opened: September 03, 2016
    • Date Closed: February 22, 2017
    • Recall: No recall issued

    Component(s): Service Brakes
    Service Brakes, Hydraulic
    Service Brakes, Hydraulic:Foundation Components:Disc:Pads

    Summary: The Office of Defects Investigation opened this investigation on September 3, 2016 based on four reports alleging the rear brakes locked or applied while driving without brake pedal application. One of the reports alleged a fire in the right rear wheel area.The vehicles subject to the investigation are equipped with an optional Electronic Parking Brake (EPB). In this system, an electric motor applies the parking brake by moving the rear brake pads (pads) against the brake rotors (rotors) when activated by the EPB control switch. The EPB is released by the control switch or by selecting a drive gear with the transmission shifter when the ignition is on.If the EPB has not been used within 1000 kilometers (621 miles) the system is designed to perform an Automatic Adjustment Function (AAF) of the pads to check for proper clearance. This function is a pad adjustment only and is preformed with the vehicle in park with the ignition off. It does not set the parking brake or turn the brake indicator light on. Hyundai has identified an error within the EPB control logic that can cause the pads to remain in contact with the rotors at various levels of force after the AAF is completed. This condition could cause the rear brakes to drag at the next drive cycle and may generate some levels of heat and smoke. The EPB control logic error affects model year 2016 vehicles produced from the start of production through March 16, 2016.Vehicles produced from March 17, 2016 incorporate an updated EPB control logic to prevent brake pad drag. On May 11, 2016 Hyundai notified its dealer network of Service Campaign TFF to update the EPB control logic in the affected vehicle population. Dealers will reflash the EPB software to prevent brake pad drag.There are no reports of accidents or injuries as a result of this issue. The incident that alleged fire could not be confirmed as there were no repairs to the vehicle other than replacement of the rear brake rotors and pads.ODI is closing this investigation based on the manufacturer's Service Campaign of the affected vehicles and in consideration that the the effect of brake drag in this instance does not appear to present an unreasonable risk to motor vehicle safety. The ODI reports cited above can be viewed at www-odi.nhtsa/complaints under the following identification (ODI)numbers: 10820359, 10854476, 10875764, 10892736, and 10928478