2021 Hyundai Sonata Hybrid Other or unknown Problems
- Complaints
- 7about this part
- Share
- 13%of 55 total for the year
- Median mileage
- —not reported
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 7 complaints about the other or unknown of the 2021 Hyundai Sonata Hybrid, 13% of the 55 complaints for this model year.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“The Battery dies randomly (like I have to open the car with they physical key to access the car dead) there isn't a pattern. I have taken it to the dealership and they can't diagnose it because they cant replicate the issue and say nothing is wrong. Sometimes the car dies while I'm INSIDE and just having lunch while the car is off.”
NHTSA complaint #11575925, filed 2024-03“On three separate occasions, while going very fast (60-78 mph), the automatic emergency braking system turns on. The warning lights flash and there is some type of warning noise. I don't even know if it starts to break because it scares me so much, I just press the gas. It turns off within a couple of seconds, but that is not the point. If I didn't react so fast, I am unsure of what could actually happen.”
NHTSA complaint #11627928, filed 2024-11“My 2021 Hyundai Sonata Hybrid seems to be leaking coolant into the exhaust system. Various reports online indicate that this is a consistent issue with 2020-2022 Hyundai Sonata Hybrid models. A lot of the reports indicate that owners have tried getting theirs cars repaired for the same issue I have a various dealerships all across the US, but either haven't had any luck or have had a temporary fix for the issue, which proceeded to occur again every couple of months. …”
NHTSA complaint #11636925, filed 2025-01“On Wednesday, October 6th, I was driving full speed (65mph) on a major highway. Multiple lights on the dashboard came on. The LCD display screen for music, apps, etc. went black. More lights came on and others went off on the dash display. I let off the accelerator and steered the car. The fuel efficiency was wilding jumping back and forth. Soon enough, all the lights went back off, but the mileage gauge (fuel efficiency) continued to jump wildly. The brakes seemed to respond differently- almost as if there was a delay between me pressing the brake and the brakes catching. …”
NHTSA complaint #11436473, filed 2021-10“Antifreeze is coming out of the exhaust. Heater is only blowing cold air. Repair shop said it is a common problem with the Hyundai hybrids. Was told I had to take it back to the dealership. The y repair shop said this is very common and is wondering why a recall has not been issued by the NTHSB. Dealership has been unresponsive.”
NHTSA complaint #11562721, filed 2023-12Other or unknown: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2025 | 3 | 27% |
| 2024 | 1 | 11% |
| 2023 | 1 | 7% |
| 2022 | 5 | 26% |
| 2021 | 7 | 13% |
| 2020 | 4 | 25% |
| 2019 | 1 | 20% |
| 2018 | 1 | 11% |
| 2017 | 11 | 14% |
| 2016 | 19 | 14% |
| 2015 | 6 | 11% |
| 2014 | 1 | 4% |
| 2013 | 10 | 9% |
| 2012 | 15 | 10% |
| 2011 | 9 | 9% |
Other parts of the 2021 Hyundai Sonata Hybrid
25 complaintsEngine
21 complaintsFuel system
5 complaintsTransmission and drivetrain
4 complaintsEngine cooling
3 complaintsForward collision avoidance
3 complaintsBody and structure
1 complaintsTires
1 complaintsVisibility (wipers, defrost, mirrors)
1 complaints
← All problems reported for the 2021 Hyundai Sonata Hybrid
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 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