Problems · NHTSA complaints
2019 Hyundai Sonata Plug-in Hybrid problems
Owners filed 5 complaints about the 2019 Hyundai Sonata Plug-in Hybrid with NHTSA between Sep 2020 and Jul 2026. The most-cited component is fuel/propulsion system (3).
Complaints
5
Filed with NHTSA
Crashes
0
Reported by owners
Fires
0
Reported by owners
Injuries
0
People reported injured
Deaths
0
Reported to NHTSA
Complaints by component
One complaint can cite several components
- Fuel/propulsion system3
- Power train2
- Electrical system2
- Engine1
- Other / unknown1
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
Data from NHTSA Complaints API · synced Nov 12, 2026NHTSA vehicle page
When complaints were filed
Does it get worse with age? Complaints per calendar year filed
2
0
1
1
0
0
1
View as table
| Model year | Complaints filed per calendar year |
|---|---|
| 2020 | 2 |
| 2021 | 0 |
| 2022 | 1 |
| 2023 | 1 |
| 2024 | 0 |
| 2025 | 0 |
| 2026 | 1 |
Mileage at failure isn’t a structured field in NHTSA complaint data, so we don’t chart it. Some owners mention it in their reports below.
Top problems in owners’ words
Verbatim from NHTSA complaints, newest first
Fuel/propulsion system
3 reports
“The high voltage battery will no longer charge neither from being plugged in to the charger on the wall nor from the buikt in system onboard the car. There are warning lights saying the inverter coolant is low but the reservoir is at the proper level. I suspect the coolant for the Hybrid charging inverter is bad and crystalizes causing blockages in the inverter coolant system. My car refuses to charge for the last 2 years. After a few seconds (about 7-10) the car shuts off the charging system when plugged in. And now that summer heat us here in the South West, it will not even charge from the regenerative braking. The high voltage battery previously would maintain 10-15% charge from the gas engine and regenerative braking. Now it's sitting at 1%. Because the battery is so low the electric motor does not produce power, and the gas engine is under powered on its own. This makes acceleration from a stop light/sign sluggish, slow and dangerous. Other Hyundai EV (IONIC and Kona) and PHEV (Santa Fe and Tucson) models have had their inverter coolant flushed and replace, some with a different spec coolant. This Sonata 2019 PHEV probably suffers from the same poor…”
Power train
2 reports
“I was traveling on a highway when a "hybrid system warning" suddenly appeared on the dashboard. Every dashboard warning light illuminated. The car began to lose power. I exited the highway immediately and the car began to have sporadic power and was "lurching." I immediately pulled onto the shoulder and at that time another warning on the dash appeared within a minute or two of the first warning that said "shut engine off." The computer screen began to flash on and of and the windows would not roll up smoothly. When the tow truck arrived the car wouldn't start and it didn't recognize the key fob. Hyundai now has the vehicle and claims the car needed a "software update", but they cannot tell me if it will ever happen again and cannot tell me why the car goes into critical failure when it needs a mere software update. This is the second time this has happened. The first time it was repaired under a voluntary recall campaign about a year ago. This is an extremely dangerous occurrence as the car loses power without warning. I was fortunate to be near an exit when it happened and able to safely get off the highway, but that was just luck. The manual indicates that a…”
Electrical system
2 reports
Engine
1 report
Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 12, 2026
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.