2021 Hyundai Sonata Hybrid problems & reliability
53 owner complaints filed with NHTSA for the 2021 Hyundai Sonata Hybrid. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
1 complaint report injuries (2 injured).
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Electrical System → | 25 | 47% |
| Engine → | 21 | 40% |
| Unknown OR Other | 7 | 13% |
| Engine and Engine Cooling | 3 | 6% |
| Forward Collision Avoidance | 3 | 6% |
| Fuel/propulsion System | 3 | 6% |
| Power Train | 3 | 6% |
| Structure | 1 | 2% |
| Tires | 1 | 2% |
| Visibility/wiper | 1 | 2% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Complaints by incident year
What owners report
“The vehicle experiences sudden, complete electrical power loss while driving at speed on highways and city streets or on the parking. All digital displays turn off, the engine shuts down, and power-assisted steering and braking are instantly lost without prior warning, presenting an extreme collision risk. The issue…”
Engine · filed Aug 5, 2026
“I purchased this vehicle pre-owned approximately two years ago and have since developed concerns about its reliability, particularly related to the electrical and hybrid systems. In hindsight, I suspect these issues may be part of the reason the original owner traded it in to a CarMax dealer. Shortly after purchasing…”
Electrical System · filed Jun 22, 2026
“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…”
Electrical System · filed May 22, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Pedestrian alert sounds
Defect Petition DP22005 · opened Jan 27, 2023 · closed Aug 7, 2023 · led to recall 22V063000
Technical service bulletins
48 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2021 Hyundai Sonata Hybrid. The 10 most recent:
The National Highway Traffic Safety Administration (NHTSA) has identified the presence of substandard and dangerous driver’s-side airbag inflators manufactured by Jilin Province Detiannuo Automobile Safety System Co.…
DTN DL · Other · issued Apr 10, 2026
The National Highway Traffic Safety Administration (NHTSA) has issued an urgent safety advisory regarding dangerous, counterfeit driver‑side airbag inflators manufactured by Jilin Province Detiannuo Automobile Safety…
DTN DCS · Other · issued Apr 10, 2026
Some Elantra (CN7, CN7A), Kona (OS, SX2), and Sonata Hybrid (DN8 HEV) vehicles equipped with 2.0L engines may illuminate a warning lamp for DTC P218100 (Cooling System Performance) related to the Integrated…
25-EM-007H TSB · Service Bulletin/Repair Instructions · issued Dec 18, 2025
This bulletin provides information regarding condensation related to the accumulated moisture in the headlamp, rear combination lamp, daytime running lamp (DRL), or fog lamp. This TSB illustrates the various causes of…
25-BD-012H TSB · Service Bulletin/Repair Instructions · issued Nov 6, 2025
This bulletin provides information related to the changes introduced in the 2025 1st Navigation Map and Software Update. The changes may vary depending on vehicle type, model, and navigation system as described in this…
25-BE-020H TSB · Service Bulletin/Repair Instructions · issued Sep 30, 2025
Certain Hyundai vehicles may exhibit a warning light with Diagnostic Trouble Code (“DTC”) P1BB20 due to a battery over voltage condition.
25-01-010H-1 9B4 OL · Service Campaign · issued Aug 21, 2025
Certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles may exhibit a warning light due to DTC Code P1BB20 (12V Lithium Battery Cell Voltage High). The California Air Resources…
25-01-010H-1 DN · Service Campaign · issued Jul 16, 2025
This bulletin provides the procedure to update the software for the Battery Management System (BMS) on certain Elantra Hybrid (CN7 HEV), Sonata Hybrid (DN8 HEV), and Tucson Hybrid (NX4 HEV) vehicles that may exhibit a…
25-01-010H-1 TSB · Service Campaign · issued Jul 16, 2025
This bulletin provides information related to the changes introduced in the 2024 2nd Navigation Map and Software Update. The changes may vary depending on vehicle type, model, and navigation system. Refer to the 2024…
25-BE-002H TSB · Service Bulletin/Repair Instructions · issued May 16, 2025
Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink Service functions. This may be due to an irregular disconnection on Verizon’s communication network. Follow the procedure…
25-01-024H-1 TSB · Service Campaign · issued May 8, 2025
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
No NHTSA recall campaigns name the 2021 Hyundai Sonata Hybrid in our current data. Recalls may apply only to certain VIN ranges — always confirm with a VIN check.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2021 Hyundai Sonata Hybrid?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.