Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 Hyundai Sonata. The contact received notification of the NHTSA Campaign Number: 22V746000 (Power Train) however, the contact stated that on numerous occasions while driving at various speeds, the accelerator pedal was depressed however, the vehicle decelerated and went into "fail-safe" mode. The vehicle was taken to the dealer where it was diagnosed that the transmission control unit software needed be updated. The vehicle was repaired; however, the failure recurred. Additionally, the contact stated that prior to the recall repair, while driving at an undisclosed speed, the vehicle failed to accelerate as needed. The vehicle was taken to the dealer and the transmission was replaced. The vehicle was not repaired. …
The contact owns a 2021 Hyundai Sonata. The contact became aware that the VIN was included in NHTSA Campaign Number: 22V746000 (Power Train); however, parts to do the recall repair were not yet available. The local dealer was contacted. The contact stated that the vehicle would delay while starting. The vehicle was taken to the dealer where it was diagnosed but no issues were found. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue and informed the contact that a recall notification would be mailed to him in December. The failure mileage was approximately 15,000. VIN tool confirms parts not available.
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle made abnormally loud sounds. The vehicle was taken to the dealer where it was diagnosed that the transmission needed to be replaced. The dealer informed the contact that they were awaiting approval from the manufacturer to perform the repair. The vehicle was not repaired and remained at the dealer. The manufacturer was made aware of the failure. Upon investigation, the contact related the failure to Manufacturer Recall Number: 236 (Power Train) included with the VIN; however, he had not yet received notification. The failure mileage was approximately 28,000.
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at 30 MPH and depressing the accelerator pedal, the vehicle failed to respond and lost power. The vehicle was coasted over to the right side of the road, turned off, restarted, and returned to normal functionality. An independent mechanic was contacted. The vehicle was taken to an independent mechanic to be diagnosed; however, the diagnosis was unknown. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 22V746000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was not notified of the failure. The failure mileage was 35,000.
The contact owns a 2021 Hyundai Sonata. The contact stated while driving 65 MPH and attempting to accelerate, the vehicle failed to respond with the check engine warning light illuminated. The contact also heard a knocking sound coming from the vehicle. The contact pulled over on the side of the road and turn off and restarted the vehicle and the vehicle started operating as designed. The vehicle was taken to the dealer and the contact was informed that the transmission and engine needed to be replaced. The manufacturer was contacted but offered no assistance. A case was filed. The failure mileage was 2,700.
The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the vehicle lost motive power with the oil warning light illuminated. The contact was able to restart the vehicle; however, the failure recurred. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The contact related the failure to NHTSA Campaign Number: 22V746000 (Power Train); however, the VIN was not included in the recall. The failure mileage was approximately 41,000.
My transmission on my 21 Hyundai sonata n line has failed. It began when the car needed to emergency brake when someone jump into my lane on the road. There's grinding, and whining in the transmission along with delayed shifts, jerking and a burning smell that comes through the vents of my car upon start up. The recall on this transmission is because it may become defective. I bought the vehicle from a Honda not a Hyundai dealer in March of 2023 the recall campaign closed out Jan of 2023. According to Hyundai records show that the TCU update remedy was performed Jan of 23. However, even though that TCU update was performed, 2 years later my transmission began to fail. I brought it to my local dealer for a transmission drain and refill not a flush. Per the service manual it's a drain and refill however they flushed it which caused the transmission to worsen. …
I own a 2021 Hyundai Sonata 1.6T, which has an open NHTSA safety recall (25V796000) related to fuel tank pressurization and fire risk. I brought the vehicle to an authorized Hyundai dealership due to a check engine light, reduced performance, and DTC P14EE, which aligns with the recall condition. The dealership refused to treat the concern as recall-related unless I paid a diagnostic fee and later attempted to reclassify the issue as a customer-pay fuel pump repair. During this visit, the dealership replaced a fuel system sensor without my authorization, which I did not approve or consent to. The dealership has not provided documented test results explaining how the recall condition was ruled out and has not documented recall inspection on the repair order. I expressed that I do not feel safe driving the vehicle due to the fuel system recall and drivability issues. …
My 2021 Hyundai Sonata N Line suffered a catastrophic, sudden total loss of drive power while operating at speed on a public roadway, creating an immediate crash hazard. The vehicle lost forward propulsion and the gear selector flashed a blinking 'R' when reverse was attempted. The vehicle was towed to an authorized dealer, [redacted] Hyundai Southtowne, where their factory GDS tool pulled transmission code P283601 (Shift Fork 'B' Position Circuit). This matches the exact critical safety failure path targeted by Federal Safety Recall 236 (NHTSA Campaign 22V-746) for the 8-speed wet-DCT high-pressure electric oil pump circuit failure. The vehicle previously received the 2022 software patch, but the underlying physical hardware has now actively degraded. The dealership is attempting to deny the federal safety recall remedy based on the vehicle's high mileage. …
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. …
Related recalls
Power train › Automatic transmission
Hyundai Motor Company (Hyundai) is recalling certain 2021-2022 Santa Fe, Sonata, Veloster N, 2022 Santa Cruz, Elantra N, and Kona N vehicles. The vehicle's "fail-safe" limited-mobility drive mode may be impaired, when prompted by a transmission oil pump malfunction, which can result in a complete loss of drive power.
Remedy: Dealers will inspect and replace the transmission, as necessary. Dealers will also update the transmission control unit software. All repairs will be performed free of charge.
Transmission complaints in other Sonata years
Frequently asked questions
How common are transmission problems on the 2021 Hyundai Sonata?
NHTSA has 25 complaints about the transmission & drivetrain of the 2021 Hyundai Sonata, 19% of the model year's 134 complaints. The component named most often is automatic transmission (1 mentions).
Is there a recall for 2021 Hyundai Sonata transmission problems?
Yes — NHTSA recall 22V-746 (automatic transmission, Oct 6, 2022). Recall repairs are free at authorized dealers.
At what mileage do 2021 Hyundai Sonata transmission problems start?
Half of the complaints with a recorded mileage happened before about 28,000 miles, and 50% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.