2021 Hyundai Sonata Hybrid

The Battery dies randomly and requires the physical key to unlock the door. It is a hybrid, so it has a 12 volt battery button that jumpstarts the car. While driving the vehicle, the battery meter on the dashboard will show a near-full battery and then a near-empty battery within a few minutes. This vehicle was bought brand new from a Hyundai dealership and for the first 2 years, there wasn't an issue. The past few months, the battery issue started.

the car keeps randomly dying (not during driving "yet") it happens at least once or twice a week of where i go to ride my car and it is completely dead, i have to unlock the door using the key fob manually and push the "Reset 12v battery button" inside the car. i have tried to have Hyundai service repair the issue or at least tell me what's wrong but no hope as they can never replicate the problem. I am seeing alot of users posting online on numerous web forms (reddit,facebook..etc) that they are having the same exact issue as me for the same exact model of my car, With also no help from the dealer on the matter. This must be a defect at some point and would greatly appreciate if NHTSA can help push this issue to the dealer

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.

Integrated 12V battery dies with no warning and requires manual keyed process to get in to the vehicle. Once inside, the battery reset button needs to be pressed to have the solar battery start the vehicles electric system. After a few minutes the engine takes over to start charging the battery. I have had the battery die 3 times on the 2021 Hyundai Sonata Hybrid in one week. Other postings online indicate others owners are having issues with the battery also with one owner loosing power while operating the vehicle on the freeway. After safely coasting the vehicle to the shoulder, the reset battery button restarted the electrical system for the car. Possibly an issue with the 12V battery implementation with the solar battery?

Initially had loss of cabin heat. Later, vehicle randomly overheated. Repair shop replaced EGR due to finding confidant buildup of water/coolant mix. Within one week, problem returned. Dealer notified me that while replacing another part they found a TSB for coolant leakage into exhaust that was consistent with my issue. After research, it is clear that this is a widespread failure and should be a recall.

Hyundai 2021 Sonata Hybrid. Blown head gasket. Reported 1,000 miles after warranty expired. Car was in the shop for Hybrid battery issues. Repair completed. 2 weeks later smoke coming from the exhaust. Hyundai says blown head gasket - will not honor warranty as I was just a few thousand miles over warranty. Seems to be a common problem with the Hyundai not honoring the warranty.

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.

My vehicle's heat stopped working suddenly. A short while later, I received and overheat warning for the engine. I had to stop repeatedly on the shoulder of the highway to allow the car to cool so I could move it to a safe space at the next exit. The dealer has confirmed that the coolant was leaking into the exhaust system and burning up. This resulted in white smoke, inconsistent power, and a stumbling engine when it would switch over from the electric to the gas engine. This problem comes on suddenly and can leave you in a very bad situation since there is no warning to this problem. The dealer reported my car had no coolant left in it which is why it was frequently overheating. I have read about this problem on many online forums and it seems to be very common in this car. Hyundai needs to create a fix.

The vehicle has been turning completely off after use for over a year now. At first it would happen every now and then at the beginning and all you'd have to do was restart the car manually. Now every time the car is turned off it needs to be restarted manually now. The car will also shut itself off while you are driving. It will tell you something is wrong and then won't let you get over 15-20 MPH. If you are on a neighborhood, it's less dangerous for this to happen where you can pull over and turn off the car and restart it. But I have seen other post that they've started to malfunction on the freeway and highways before. My car is a 2021, but recently I've seen 2023 models are doing this as well. I know some people on the internet have gotten their car fixed by replacing a back logged battery. It took some people over a year to get it diagnosed correctly and 6 more months to get a new battery. I assume this is also what is wrong with my vehicle. It is in the shop right now, but we have not gotten an answer back even htough it's been there for 10 days. The car app has also indicated that the car has not been turned on since we left it there.

While driving, engine alerted that it was overheating. Pulled over and coolant was very low, so I refilled it and then while driving to my family's garage to use the lift, saw white exhaust smoke. Took it to an independent mechanic, and in the ~10 mile trip there, over a quart of coolant had been burned off. He was able to reproduce the issue. No issues with the engine operation, it runs well and efficient, no check engine light. Mechanic found that a coolant line runs to the middle of the exhaust system and that this seems to be the issue. Other owners seem to have reported this same issue with this same model and roughly the same year, in which the muffler assembly needs replaced due to coolant leaking into the exhaust. Only prior issue was less warm air out of the vents for the previous week or so, but no other issues or warnings.