Hyundai Sonata Complaints

17,026 consumer complaints on file.

#11741226June 1, 2026
POWER TRAIN
The vehicle has experienced repeated transmission and Electronic Oil Pump (EOP) failures resulting in loss of propulsion, loss of acceleration, and transmission-related malfunctions. The vehicle currently has approximately 69,000 miles. On September 3, 2022, the vehicle lost propulsion while traveling approximately 31 MPH in traffic and would not respond normally to accelerator input. This created a dangerous situation and increased the risk of a collision. On the same date, while backing out of a parking space, the vehicle displayed a "Shifter System Malfunction" warning message and unexpectedly stopped while in reverse. The vehicle had to be powered off before it would operate again. Following these incidents, the vehicle was towed to a Hyundai dealership and the transmission was replaced in September 2022. Despite the transmission replacement, the vehicle continued experiencing issues involving the same system. The Electronic Oil Pump (EOP) was replaced in 2023 and again in 2024 due to recurring transmission-related concerns and diagnostic codes. In 2026, the check engine light returned and the vehicle was again diagnosed with a transmission-related failure. The dealership determined that the transmission requires replacement for a second time despite the previous transmission replacement and two separate EOP replacements. Internally, Hyundai has since revised its repair guidance for this condition, suggesting that prior repair procedures may not have fully addressed the underlying defect. The repeated failures of the transmission and EOP system despite multiple repairs suggest an underlying defect that has not been corrected. These failures create a significant safety risk because the vehicle can unexpectedly lose propulsion or fail to accelerate while operating in traffic. The vehicle is available for inspection upon request.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741201June 1, 2026
ELECTRICAL SYSTEM, ENGINE
The car will idle high around 1200 rpms. The car will most of the times fix the issue when you turn the car off and back on but it will start again after driving. This is a known issue with the car. I have had the egr valve replaced since it will pop up the codes P240F and P049 for egr slow response and control position exceeded learning limit but the problem came back within two days. I did find a forum that deals with the joint connector repair but this needs to be a recall as I have come across many people who have this problem and paying out of pocket to fix it.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741142May 31, 2026
ENGINE, POWER TRAIN, FUEL/PROPULSION SYSTEM
I am submitting this complaint regarding a serious safety issue involving my Hyundai Sonata. While driving under normal conditions, my vehicle suddenly entered a low-power ("limp") mode without warning. The vehicle would not accelerate beyond approximately 30–35 mph, creating a potentially hazardous situation in traffic. At the same time, the check engine light began blinking. The sudden loss of power significantly reduced my ability to maintain traffic speed and safely maneuver the vehicle. This condition could have increased the risk of a rear-end collision or other accident. I brought the vehicle to an authorized Hyundai dealership (Fred Beans Honda Of Abington PH# 215-392-9020) for diagnosis. The dealership confirmed that the vehicle stored Diagnostic Trouble Code (DTC) P1326, related to the Knock Sensor Detection System (KSDS). According to the dealership, the vehicle entered limp mode as a result of this fault. The abrupt reduction in vehicle power and speed occurred without sufficient warning and created a safety concern. I am reporting this incident so that NHTSA can investigate whether this condition represents a broader safety defect affecting Hyundai Sonata vehicles equipped with the KSDS system. Vehicle Information: Make: Hyundai Model: Sonata Model Year: 2014 I request that NHTSA review this issue and evaluate whether additional action is warranted regarding vehicles experiencing DTC P1326 and associated limp-mode operation.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741173May 31, 2026
ENGINE
2020 Hyundai Sonata SEL Plus, VIN [XXX] . A/C system fails due to refrigerant leak that empties the system completely within 1-2 weeks of recharge. Leak cannot be located through standard external inspection. First noticed reduced cooling summer 2025. Driver's side loses cooling first, then passenger side fails days later — pattern consistent with evaporator core leak in dual-zone system. In September 2025, independent shop found system completely empty, recharged it, and attempted leak detection but could not locate source. Approximately two weeks later, system was empty again. Shop still unable to find leak. Symptom pattern — rapid total refrigerant loss, asymmetric failure (driver side before passenger), no externally detectable leak — points to evaporator core, which is enclosed in the HVAC housing behind the dashboard and invisible during standard inspection. Vehicle has 50,125 miles, still under the 60,000-mile warranty limit after 6+ years. Low-use vehicle averaging under 8,000 miles/year. 5-year calendar warranty expired approx. Jan 2025; issue first documented Sept 2025, only 8 months later. Defect was almost certainly present before warranty expiration. A class action investigation is underway (XXX) for premature A/C failures in 2018-2022 Sonata, Elantra, Palisade, Santa Fe, and Tucson vehicles. Loss of A/C in Texas climate poses risk of heat illness to occupants, especially children. This component should not fail at under 50,000 miles. Original lessee and purchaser; vehicle well maintained. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741174May 31, 2026
FUEL/PROPULSION SYSTEM, ENGINE, ELECTRICAL SYSTEM
Supplemental Information to Existing NHTSA Complaint involving a 2017 Hyundai Sonata Plug-in Hybrid (VIN: [XXX] ) While traveling at approximately 70 MPH on a heavily traveled highway, the vehicle suddenly and completely lost propulsion without warning. The vehicle rapidly decelerated in traffic, creating a significant safety hazard for my family and surrounding motorists and requiring emergency maneuvering to reach the shoulder. The vehicle was towed to an authorized Hyundai dealership, where diagnostic testing identified multiple high-voltage battery system fault codes: • P0B68 • P0B6D • P0B72 The dealership diagnosed a high-voltage battery system failure requiring battery replacement. The vehicle is currently non-drivable. During my research, I found multiple owner reports involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles experiencing loss of power, hybrid system failures, limp mode conditions, and propulsion-related incidents. I also learned that Hyundai previously issued Recall 18V166000 involving 2016–2018 Sonata Plug-in Hybrid vehicles due to battery management system and voltage protection device concerns that could result in loss of power while driving. Dealer says does appply for my car. Although my vehicle’s fault codes may differ from those addressed in the recall, both involve battery-related failures capable of affecting propulsion and creating a highway safety risk. My concern extends beyond my individual vehicle. A high-voltage battery or battery management system failure that can cause a complete loss of propulsion at highway speed without warning presents a potentially serious safety risk. I respectfully request that NHTSA evaluate whether similar incidents involving Hyundai Sonata Hybrid and Plug-in Hybrid vehicles indicate a broader safety concern warranting further review. I can provide dealership diagnostic reports, repair estimates, towing records, photos, and videos upon request. Thank you for your consideration, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATI
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11741184May 31, 2026
SERVICE BRAKES, WHEELS, VEHICLE SPEED CONTROL
Hyundai Sonata SEL - 2022 Both Leg break and hand break didnt work while driving. its a very severe issue in this model.
Crash:
Yes
Fire:
No
Injuries:
0
Deaths:
0
#11741060May 30, 2026
ENGINE
2015 Hyundai Sonata 2.4L Theta II GDI engine experienced complete failure due to connecting rod bearing defect. Vehicle was taken to a Hyundai dealership prior to failure to report engine knock symptoms. Dealer confirmed KSDS (Service Campaign 953) was installed but performed no inspection and provided no repair order. Engine subsequently failed with no warning light activation despite KSDS being installed. This is a known defect covered under the Theta II class action settlement lifetime warranty. Warranty repair has not been provided and no loner car has been provided.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740786May 29, 2026
ENGINE
My 2011 Hyundai Sonata (VIN [XXX] ) was brought to Gateway Hyundai in [XXX] for the mandatory P1326/KSDS engine recall inspection. I had a confirmed appointment on XXX at 7:30 AM. The dealership acknowledged the P1326 code and that the KSDS test was required.Instead of performing the recall, the dealership refused to inspect the vehicle. They contacted a third party who was not in possession of the vehicle and released the vehicle to that person without my authorization. The plates were removed and the vehicle was later sold without my consent. The recall was never performed and the engine defect was never inspected.This is a failure to perform a required safety recall and a violation of chain-of-custody procedures. A vehicle with a known engine failure risk was put back into public circulation without inspection. This creates a safety hazard for the public.I also suffered financial harm including $1,500 in towing, parts, labor, and storage fees. I have a signed tow invoice showing the VIN and the total amount paid.I am requesting that NHTSA investigate Gateway Hyundai’s handling of recall vehicles, review their authorization and release procedures, and take enforcement action if violations are found. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740813May 29, 2026
FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
The contact owns a 2020 Hyundai Sonata. The contact stated while driving at various speeds, the vehicle experienced phantom braking and nearly came to a complete stop. The contact stated that the automatic emergency braking system unexpectedly engaged while there were no roadway obstacles or vehicles near the vehicle. The vehicle was taken to the dealer, who informed the contact that they would need to verify whether the repair would be covered under the active warranty. The vehicle was not yet diagnosed or repaired. The manufacturer was not yet contacted. The failure mileage was approximately 2,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740561May 28, 2026
FUEL SYSTEM, GASOLINE
See attached document for complaint.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740602May 28, 2026
ENGINE, UNKNOWN OR OTHER
I am writing to report a serious, premature failure of a primary emissions and safety-related component (the catalytic converter) that has occurred as a direct consequence of a known, unaddressed manufacturing defect in Hyundai's Theta II engine. My vehicle has a documented history of excessive engine oil consumption. This inherent manufacturing flaw causes the engine to burn motor oil at an extreme rate, forcing unburned oil directly into the exhaust system. Over time, this oil has fouled and destroyed the catalytic converter substrate, triggering trouble code P0420 and causing a complete component failure. A dealership inspection at Heritage Hyundai Towson (RO #XXX) confirmed "excessive wear" and failure of the catalytic converter. Because the catalytic converter is failing prematurely due to a liquid defect (excessive oil burning) rather than standard wear and tear, it poses an environmental hazard, compromises vehicle emissions control, and can lead to sudden engine stalling or reduced power while driving, presenting an active safety risk. Hyundai Motor America (Case #XXX) has formally denied assistance to rectify this consequential damage, despite full awareness of the underlying engine defect. I request that NHTSA investigate how Hyundai’s ongoing oil consumption manufacturing issues are causing cascading safety and emissions component failures in these vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740755May 28, 2026
POWER TRAIN, ELECTRICAL SYSTEM
2022 Hyundai Sonata N Line, VIN [XXX] , purchased August 15, 2025 with low mileage under original manufacturer warranty. Within 3 months, recurring transmission and drivability failures began. Six repair visits since November 2025; 71+ cumulative days out of service within 8 months. Visit 1 (11/24/25, 14,748 mi): Hesitation/failure to accelerate from stop. Could not duplicate. Visit 2 (12/4/25, 14,800 mi): Same concern. Fault codes found; auxiliary pump and relay replaced. Visit 3 (1/19/26, 15,982 mi): Check engine light, jerking. External oil pump leaking; replacement required. Visit 4 (1/30/26, 16,025 mi): Check engine light. TCU update, DCT learning performed; declared resolved. Visit 5 (2/19/26, 16,119 mi): Check engine light returned. Transmission oil pump failed; replaced. Visit 6 (4/14/26, 16,945 mi — OPEN 44+ days): Post-repair lurching, infotainment failure, ongoing jerking. On 5/28/26, the service manager at McDonough Hyundai (McDonough, GA) stated the vehicle likely requires a complete transmission replacement and disclosed approximately 4 additional vehicles at the same dealership with identical unresolved issues. Hyundai Motor America refuses to authorize repairs or Techline escalation unless the dealership confirms the intermittent concern — a structural barrier that prevents warranty resolution. Safety concern: repeated failure to accelerate normally from a stop creates direct risk of rear-end collision or inability to clear intersections. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740717May 28, 2026
ELECTRICAL SYSTEM
The contact owns a 2022 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the HVAC blower motor became inoperable with no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the blower motor fuse had melted and failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 70,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740495May 27, 2026
ENGINE
The rod bearings failed in the engine. The vehicle is currently at the dealership and is available for inspection. Rod bearing failure can cause complete engine seizure while driving, creating a serious risk of losing vehicle control at any speed. This is a known issue with Hyundai's Theta II engine. Yes. The dealership performed a diagnostic on April 27, 2025 and confirmed rod bearing failure. Yes. The dealership inspected the vehicle and Hyundai corporate opened a warranty case and arranged the repair appointment, initially confirming coverage before later denying the claim without providing documentation. The dealership has also repeatedly failed to provide documentation supporting the denial of my warranty claim despite my requests beginning April 29, 2025. I have also been unable to get callbacks from the dealership after being promised updates on May 1st, May 7th, and after requesting a manager on May 18th. As of May 27, 2025 I have still not received any documentation or a callback. The check engine light came on prior to the failure. I proactively checked and changed the oil, added Lucas oil treatment, replaced the spark plugs, and replaced the battery attempting to diagnose and resolve the issue before bringing it to the dealership. No oil pressure warning light ever appeared. The check engine light persisted despite these efforts which is what led me to bring the vehicle in.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740388May 27, 2026
ENGINE AND ENGINE COOLING
The contact owns a 2015 Hyundai Sonata. The contact stated while driving at various speeds, the vehicle skipped and failed to exceed 35 MPH. The contact received notification of Hyundai Service Campaign Number: 9C2 (ECU SOFTWARE UPDATE FOR THETA II EMISSIONS IMPROVEMENT), and the vehicle was towed to the dealer, where it was diagnosed and determined that the catalytic converter was clogged and needed to be replaced at the owner's expense. The vehicle was not yet repaired. The contact's son, who was an independent mechanic, determined that the ECU might have sent erroneous signals to the O2 sensors, who then sent excessive fuel into the catalytic converter, causing a catalytic converter clog. The manufacturer was notified of the failure and was informed of the Service Campaign notification, but the manufacturer denied assistance due to the mileage and lack of warranty coverage. The failure mileage was approximately 140,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740030May 26, 2026
POWER TRAIN, ENGINE
The contact The contact stated that when taken the vehicle for a service campaign repair and shortly after went for recall r The vehicle does not run properly on cold starts, the RPMs increase rapidly and slow down, vehicle jerks forward once beginning to drive.. The vehicle does not have this issue once the vehicle is warm. The manufacturer was not notified of the issue. The approximate. Failure mileage was 47,575.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740078May 26, 2026
STEERING, TRACTION CONTROL SYSTEM
The contact owns a 2015 Hyundai Sonata. The contact stated that while driving at lower speeds, the steering wheel became difficult to steer in either the left or right direction. The Traction Control, Power Steering, and the high-beam warning lights were illuminated. The vehicle was taken to a local independent service center, where it was diagnosed with error codes: C167286, C126008, C136008, C126002, and C168808. The vehicle was not repaired. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 195,000.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11740144May 26, 2026
ENGINE
Was driving the vehicle up Berthoud Pass on [XXX] . Was a few miles past Berthoud Falls and realized that the vehicle power diminished, noticed smoke coming from the engine. Pulled over and noticed leaking underneath the engine. It appears that a bolt came loose and punctured the engine block. After further research, it appears that this engine recall should have applied to my vehicle, but did not: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11739988May 26, 2026
SERVICE BRAKES, ELECTRICAL SYSTEM, FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING
We were backing up and leaving a parking space when the emergency braking system overrode our driving and forced a stop. This has happened many times, once while turning at a red light (which we had the right-of-way) and our car stopped on the middle of the intersection. Another time was during a turn in a non-traffic light turn lane where timing is important. Our car was again completely stopped in the middle of the road in oncoming traffic.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0
#11739503May 22, 2026
ELECTRICAL SYSTEM
The vehicle’s 12-volt electrical system repeatedly loses power within about 1 hour of sitting. The car becomes completely unresponsive (cannot unlock or start) and requires use of the built-in 12V battery reset button to restore power. This occurs frequently and makes the vehicle unreliable and potentially unsafe, as the car may become inoperable without warning. This appears to be an electrical system defect or parasitic power drain. The issue has been ongoing.
Crash:
No
Fire:
No
Injuries:
0
Deaths:
0

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