2021 Hyundai Sonata Transmission and drivetrain Problems
- Complaints
- 25about this part
- Share
- 19%of 135 total for the year
- Median mileage
- 21,500miles
- Trend
- RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA recorded 25 complaints about the transmission and drivetrain of the 2021 Hyundai Sonata, 19% of the 135 complaints for this model year. Where a mileage was given, the median is 21,500 miles. 1 recall campaign on record is filed under a similar system.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“After initial startup and drive for a short time, I come to a stop. Then after vehicle doesn’t want to accelerate as it normally would. Vehicle struggles to gain speed but, the engine revs excessively. I pull off the road and come to a stop and try to accelerate again and the same thing happens. I shut the vehicle off and wait a few minutes,then restart and the vehicle accelerates normally again. There were no check engine lights the when this has happened.”
NHTSA complaint #11676441, filed 2025-07“I took off from the house about 1 mile the car stop in the middle of the road with no warning, lights or anything. Thank God I didn’t get an accident we took the car to the dealer and the dealer telling us it’s not covered by warranty. This is 2021 Hyundai sonata lease with only 44,000 miles my wife is so scared to driving Hyundai anymore. We talk to the dealer they don’t give us loaner car still one week from now they are telling us to pay $13,000 for the repair.”
NHTSA complaint #11546182, filed 2023-09“Car transmission seemed to make a clunking sound when selecting gear from park. The car would not accelerate, the throttle seemed to be stuck and the transmission would try to downshift, but the car was not picking up speed. I eventually pulled off the road into a parking lot and turned the car off. I then restarted the car and it seemed to clear the problem, but no warning lights ever came on, and no error codes were displayed on the instrument cluster.”
NHTSA complaint #11495865, filed 2022-12“Vehicle suddenly lost heat in 30 degree weather. No warnings, check engine light, or temperature gauge indicators came on. Lucky made it to a parts store and found out I was extremely low on coolant. Bought coolant and put it in. Made it back to the house and was immediately low again. No visible leaking. Oil was completely fine (1 gallon of coolant would have have left some kind indicator). Realized it was more than likely the ehrs. If this happened during the summer, my engine could have blown due to a poor design causing a major accident.”
NHTSA complaint #11718194, filed 2026-02“Transmission replaced twice and all of them continue to fail. Several Hyundai service centers are unable to determine the cause and are only able to update/relearn and replace whenever they are able to replicate the issue. The issue is that at a cold start, the car makes a popping sound, jerks and shakes. The car hesitates to accelerate. You can hear the noise of acceleration but RPM does not go past 3 and MPH doesn't go past 30mph. I'm unable to upload docs because of the upload limit. If there's another way to send docs, please let me know”
NHTSA complaint #11764277, filed 2026-09Related recalls
- 22V746000Oct 6, 2022Hyundai 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…Covers: Hyundai Sonata 2021–2022, Santa FE 2021–2022, Veloster N 2021–2022 +3 more
Related service bulletins
- 11033840Jun 5, 2026This bulletin provides information related to a Transmission Control Unit (TCU) software update for some vehicles equipped with an 8-speed wet dual clutch transmission (8WDCT)…
- 11029937Mar 3, 2026Some Santa Cruz (NXT), Santa Fe (TMA, MX5A), and Sonata (DN8A) models may require replacement of the 8-speed wet dual clutch transmission (8WDCT) when the vehicle sets one of the…
- 11018891May 30, 2025Certain Santa Fe (TMA) and Sonata (DN8/DN8A) vehicles equipped with 8-speed dual clutch transmissions (8DCT) may exhibit one of the DTCs listed below, related to the high…
- 10253275Apr 9, 2024This TSB provides a procedure to diagnose and replace, if necessary, an automatic transmission with Incorrect Ratio DTC (transmission clutch slip in gear above limit) listed on…
- 10251294Feb 29, 2024This bulletin provides the procedure to update the Engine Control Module (ECM) and/or the Transmission Control Module (TCM) for 2020-2023MY Sonata (DN8/DN8a) vehicles to improve…
- 10251293Feb 28, 2024This bulletin provides the procedure for updating the automatic transmission TCU and ECU software (Santa Fe ONLY) to improve shift quality, judder with ISG enabled and hesitation…
- 10245580Nov 10, 2023This TSB provides information to diagnose the push button shifter operation.
- 10243329Sep 14, 2023If you are servicing an 8-speed front-wheel-drive vehicle equipped with automatic transaxle with one or more of the DTC or symptoms listed below, refer to the Service Procedure…
- 10241891Aug 28, 2023This bulletin outlines changes to the service procedure regarding the replacement of 8-speed wet dual clutch transmissions (8WDCT) and associated transmission control unit (TCU)…
- 10241890Aug 28, 2023This bulletin provides information related to a Transmission Control Unit (TCU) software update for certain vehicles equipped with an 8-speed wet dual clutch transmissions…
Transmission and drivetrain: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2025 | 3 | 18% |
| 2024 | 6 | 13% |
| 2023 | 17 | 19% |
| 2022 | 24 | 25% |
| 2021 | 25 | 19% |
| 2020 | 24 | 13% |
| 2019 | 8 | 5% |
| 2018 | 40 | 11% |
| 2017 | 56 | 7% |
| 2016 | 59 | 8% |
| 2015 | 135 | 12% |
| 2014 | 55 | 7% |
| 2013 | 94 | 5% |
| 2012 | 97 | 6% |
| 2011 | 173 | 5% |
| 2010 | 21 | 6% |
| 2009 | 41 | 9% |
| 2008 | 14 | 3% |
| 2007 | 9 | 1% |
| 2006 | 22 | 2% |
| 2005 | 5 | 3% |
| 2004 | 10 | 5% |
| 2003 | 10 | 5% |
| 2002 | 11 | 3% |
| 2001 | 18 | 9% |
| 2000 | 19 | 7% |
| 1999 | 14 | 11% |
| 1998 | 12 | 24% |
| 1997 | 9 | 18% |
| 1996 | 5 | 22% |
| 1995 | 15 | 23% |
| 1993 | 9 | 35% |
| 1992 | 5 | 23% |
| 1991 | 7 | 24% |
| 1990 | 7 | 44% |
| 1989 | 2 | 18% |
Other parts of the 2021 Hyundai Sonata
34 complaintsFuel system
34 complaintsOther or unknown
32 complaintsElectrical system
18 complaintsVisibility (wipers, defrost, mirrors)
12 complaintsForward collision avoidance
9 complaintsAir bags
4 complaintsBrakes
4 complaintsBody and structure
4 complaintsLane departure
3 complaintsSeat belts
2 complaintsSeats
2 complaints
← All problems reported for the 2021 Hyundai Sonata
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology