2021 Hyundai Sonata power train problems
24 owner complaints filed with NHTSA name the power train on the 2021 Hyundai Sonata — 18% of all complaints for this model year.
What owners report
“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…”
filed Sep 15, 2026
“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…”
filed Jun 1, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related recalls
- Vehicle's "fail-safe" limited-mobility drive mode may be impaired, when prompted by a…Campaign 22V746000 · Oct 6, 2022
Related service bulletins
This 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). The software update revises the touch…
26-AT-005H TSB · Service Bulletin/Repair Instructions · issued Jun 5, 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 high pressure electric oil pump (HP EOP)…
26-AT-001H TSB · Service Bulletin/Repair Instructions · issued Mar 3, 2026
Power Train problems in other Sonata years
| Year | Reports | Share |
|---|---|---|
| 2024 Sonata | 6 | 13% |
| 2023 Sonata | 16 | 19% |
| 2022 Sonata | 24 | 26% |
| 2020 Sonata | 24 | 13% |
| 2019 Sonata | 8 | 5% |
| 2018 Sonata | 40 | 11% |
| 2017 Sonata | 55 | 7% |
| 2016 Sonata | 59 | 8% |
| 2015 Sonata | 134 | 12% |
| 2014 Sonata | 54 | 7% |
| 2013 Sonata | 94 | 5% |
| 2012 Sonata | 97 | 6% |
Other reported problem areas on the 2021 Hyundai Sonata
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.