Hyundai Sonata transmission failure problems

Filed Jun 22, 2026 · Transmission · CA

2019 Hyundai Sonata Sport. (Original owner). Problem: Transmission. [XXX] (9,912 miles). Lack of power, vehicle did not move when trying to merge onto freeway. Very unsafe. Also, hesitation and jerking. [XXX] (10,619 miles). Lack of power, hesitation, jerking. Hyundai tech performed TSB, TCU updates, ECU update for knock sensor performance, reset engine & transmission updates. [XXX] (41,332 miles). Harsh shifts, hesitation, jerking, clunk sound, gear grabs, bursts of power, lack of power. Unsafe to drive. February 2, 2026 (41,751 miles). Hyundai tech found leak at case seal. Hyundai replaced transmission. [XXX] rough start, vibration in pedals. March 9, 2026 Hyundai tech found transmission fluid leak at case seal. Hyundai replaced transmission. March 25, 2026 Hyundai service advisor voicemail said, have to submit to Hyundai another transmission replacement because new transmission is not good. Issues shifting in reverse, hard slams, loses gears. [XXX] picked up vehicle from Hyundai service dept. Harsh shifting, hesitation, jerking, clunk sound, gear grabs, bursts of power. Clunk sound in steering wheel when turned back-and-forth. Front end vibration & wobbly. Vehicle unsafe. May 26, 2026. I notified Hyundai Motor America. Case #[XXX]. June 10, 2026 (43,000 miles). Hyundai service dept. informed me of right and left front axle replacement, universal steering joint replacement. Vehicle unsafe. [XXX] (43,000 miles). Test drove car with Hyundai tech. Verified front end vibration & shaking. Vehicle unsafe to drive. Hyundai service manager said that Hyundai should recall the transmissions. To date, my car is still at Hyundai service dept. Hyundai's service manager said that the Hyundai service dept. will have a meeting regarding my car and include Hyundai's service director, etc. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 2, 2026 · Transmission · 50 miles · MD

The contact stated that while driving at various speeds, the vehicle would jerk upon depression of the accelerator pedal without warning. In addition, the contact stated that on multiple occasions while turning into a parking lot, the vehicle's collision avoidance system would engage while in the vicinity of another vehicle as a warning chime would emit from the vehicle. The vehicle was taken to a dealer where they initially could not diagnose or duplicate the failure. The contact was asked to come and drive the vehicle herself and she was able to duplicate the failure. The dealer eventually diagnosed the vehicle with a failed transmission and remained in the dealer's possession. The manufacturer was notified of the failure. The contact was later informed that they would not replace the vehicle but would replace the transmission. The vehicle had yet to be repaired and remained in the dealer's possession. The failure mileage was approximately 50.

Filed Jun 1, 2026 · Transmission · GA

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.

Filed May 28, 2026 · Electrical, Transmission · GA

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)

Filed Sep 5, 2025 · Electrical, Transmission · AZ

2021 Hyundai Sonata with approximately 39,000 miles. On [XXX], the dashboard displayed the following message "Shifter system malfunction! Service immediately" When the warning appeared, the vehicle shifter button would not function, creating a traffic safety risk. History: Dealer service history shows the transmission was replaced on the vehicle under warranty on 08/30/2021 with 2,212 miles with no campaign/recall issued. Dealer states there is no recall campaign on this vehicles specific VIN # and the federal safety agency currently shows no open recalls for this vehicle. However, Hyundai advertises an 8-Speed DCT Safety Recall for the same year, make and model, and describes this identical issue, but has left this vehicle's VIN# out of scope for this recall, which is continuing to demonstrate the same issues. Current dealer/manufacturer response: On 9/4/2025, the dealer declined warranty or recall repair unless the fault was active on their diagnostic scan at the moment the scan was performed. A photo was provided to the mechanics of the dashboard showing the transmission service warning, with current mileage. The dealer advised there were no diagnostic log history showing the transmission error code even with photographic proof and attempted to return the vehicle to me. I have rejected the return of the vehicle and advised that this needs to be escalated, because if logs are not appearing, this is even a bigger cause for concern and that the vehicle is a safety hazard. Concern: Because this vehicle required an early transmission replacement and is now exhibiting new transmission/shifter warnings, I am concerned the failure relates to the known transmission/shifter recall on this model and that the recall scope and/or remedy is incomplete for the affected vehicles including my vin #. It is also possible the dealership is attempting to run out the warranty which expires in 3 months. Vehicle, photo of the warning, and service records are available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (

Filed Aug 22, 2025 · Transmission · FL

The contact owns a 2013 Hyundai Sonata. The contact called to report a technical issue with a Hyundai Technical Service Bulletin and the software that the manufacturer was reprograming for the Hyundai transmissions; TSB Number: 13-AT017. The contact, a certified mechanic, purchased a 2013 Hyundai Sonata from a customer due to the transmission failure. The contact attempted to order a new transmission from the manufacturer, but no transmission was available. The contact ordered a compatible transmission from Kia. The contact successfully installed the transmission. The installation instructions which stated that the motor control unit and transmission control unit software needed to be reprogramed. The contact was able to successfully road test the vehicle and then had the vehicle towed to a dealer. The contact stated that after the software was reprogramed, while attempting to road test the vehicle, immediately there were several unknown warning lights illuminated. The contact checked online and determined that the TSB issued by Hyundai for the software reprograming outlined temperature values that were not the values show on the testing equipment. The contact called the dealer and was informed that using the Kia transmission in a Hyundai vehicle, there was no assistance to be offered. The contact diagnosed the vehicle and determined that the Hyundai software was incorrect and wanted to notify the federal safety agency of the failure. The vehicle was not repaired. The manufacturer was informed of the issue. The failure mileage was not provided.

Filed Aug 7, 2025 · Transmission · NY

My certified pre-owned 2020 Hyundai Sonata has experienced the same critical transmission failure three times since October 2024, creating dangerous safety conditions on highways and city streets. Component/System Failed: Transmission control system with consistent P0768 error code (Shift Solenoid D Circuit Fault). Safety Risks: The transmission failures cause sudden power loss and inability to accelerate while driving, including on highways at speed. This creates immediate danger to myself, passengers, and other drivers when the vehicle unexpectedly loses power during traffic situations requiring acceleration or merging. Problem Reproduction: The failure has been confirmed and reproduced by authorized Hyundai dealership three separate times: - [XXX]: P0768 error, replaced shift control solenoid valve - [XXX]: Same P0768 error returned, replaced entire transmission control unit - [XXX]: Same P0768 error again, replaced complete control wiring harness with extensive dashboard removal Warning Signs: Each failure was preceded by transmission hesitation, rough shifting, and check engine light activation before complete power loss occurred. Manufacturer Inspection: Hyundai technical assistance case #[XXX] was opened for the third failure, acknowledging the recurring nature of this defect despite multiple repair attempts. Assessment: This appears to be a systematic manufacturing defect in the transmission control system affecting safety. Despite three different repair approaches by Hyundai, the identical P0768 error continues to recur, suggesting a fundamental design or manufacturing flaw that creates ongoing safety risks for drivers. The vehicle was out of service for 44 total days across these three incidents, indicating the severity and complexity of this recurring safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 7, 2025 · Electrical, Engine · CA

Dear Sir/Madam, I am writing to file a formal safety complaint regarding a dangerous incident involving my Hyundai Sonata Hybrid (VIN: [XXX] ) and Hyundai Motor America’s failure to fully correct the issue. Incident Summary: While driving on the freeway, the vehicle suddenly displayed the following alarming warnings: “Hybrid System Warning! Safely Stop and Do Not Drive” “Check Charging System” Immediately after these messages appeared, the car lost all power and shut down in the middle of the road. I had my two young children (ages XXX and XXX) in the car, making the situation extremely unsafe and traumatic. The vehicle lost all mobility and provided no opportunity to safely pull over. After contacting Hyundai Corporate multiple times, a case manager was eventually assigned to my case. At Hyundai’s request, I towed the vehicle to AutoNation Hyundai Valencia for diagnostic evaluation. The dealership diagnosed the issue as error code P0A78, indicating a transmission failure. Hyundai Corporate offered to cover 60% of the repair cost, leaving me responsible for the remaining 40%—an amount that exceeds the current value of the vehicle. This proposed resolution is not reasonable considering the severity of the safety risk and the vehicle’s low mileage. My primary concern is that this is an extremely dangerous defect, as the vehicle loses all power without warning, leaving the driver unable to move the car to a safe location. Requested Actions: A formal investigation into the safety and reliability of Hyundai’s hybrid systems, specifically in 2014 Sonata Hybrid vehicles. A determination of whether this defect qualifies under Hyundai’s warranty or federal safety defect regulations. Full compensation from Hyundai Corporate to cover 100% of the repair costs to correct this serious safety issue. Thank you for your time and attention to this critical matter. I look forward to your prompt response and appropriate action. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5

Filed Apr 30, 2025 · Engine · MI

Car transmission replaced with only 38,000 miles. Car shutters, skip gears, loss of power. Very dangerous especially when pulling out from side road on to main road. Transmission problem starts out as intermittent at first, so you never know when it will happen next. Lots of near misses where I would have been rear ended, due to shifting problems. New Transmission is already starting to shift erratically at times with only 2,000 miles on new rebuilt trans. Cost of repair is 5 to 6,000. Also own 2012 Hyundai Sonata Hybrid with the same exact transmission problems. Transmission replaced at 67,000 and now at repair shop for replacement Trans at 124,000 miles. Vin [XXX] . Both of these cars are dangerous to drive. These problems start out intermittently, and if the dealership cannot duplicate the problem, they will not fix anything, hoping to string you along past the warranty period. I tell them to check the fault code history and they tell me that they did not find any error codes. Both these cars also have the defective engine too- but so far my engines are working correctly. Invoices can be provided if needed. Found research shows that there are transmission problems with almost all generations of the Sonata's especially my 2 years - 2012 and 2014. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jan 5, 2025 · Transmission · TX

2 years after purchasing a new vehicle, the transmission began to pop and cause the car to jerk upon a cold start, RPM would increase but the speedometer would not go over 20mph. There were no error messages or alerts. I reported it several times, and the dealership technicians could not duplicate the issue and stated that the car was driving as it was designed even after providing video proof. They were later able to partially replicate the issue when the car popped and jerked after a cold start and then replaced the transmission, however, it did not resolve the issue. 1 month after the repair the car started having the same issues. After several trips to the service department, they have still been unable to duplicate the issue even with recent video proof. Based on how the technicians enter notes, the manufacturer refuses to pursue any alternative method for figuring out what is going on. This is risky because my car, upon starting cannot be safely driven and the car will shutter upon stopping at lights sometimes.