2020 Hyundai Sonata Hybrid

Over the last 3 months at least a dozen times the 12v auxiliary battery is completely dead after parking the car outdoors for an hour or so. This poses a safety issue, especially at night because you cannot easily access the car. You have to fumble around trying to get the key hole cover off in order to use the key supplied in the fob. Once you get access, you then have to press the 12v reset button in order to get the car started. This issue has been reported on the Hyundai sonata forums since the introduction of the 2020 sonata. At this point the dealer has not been able to find the issues as they say it has been occur while they have the car. Asking for the problem to occur while they are watching is unrealistic . Their calls to Hyundai tech support has been useless as they claim to have not heard of this issue.

On July 15th I was driving away from work and my car suddenly stopped accelerating. I was able to get it towed to a body shop I previously had it repaired at. They said the battery system was blowing a fuse when it would become undrivable. They took it to the local Hyundai dealership where they applied a new software update related to the battery management system. This did not solve the issue, it continues to stop while in traffic and the dealership refuses to do anything to figure out the cause.

Sudden failure of the electrical system with warning that the hybrid battery was in operable. I parked the car, turned it off, reset the 12 V battery, and the car restarted and operated normally. This problem with the 12 V battery needing reset has happened dozens of times while I was parked. This is the first time it has happened while I was driving the vehicle. A sudden disabling of the vehicle without warning poses a safety concern so I thought it best to report the problem. The local Hyundai dealership has heard of this problem, but they are unable to diagnose or repair it

Car shutdown (stops) in the highway driving 3 times last couple of weeks. - It first shows Battery Warning Light first and car shutdown on highway driving, and slowly park the side. It restarts with jump (it is hybrid system and allows jump inside the car). - When visited Hyundai Kirkland WA dealership, they found that there was an error in the Hybrid system, (v12 battery), but didn't know what's problem. - I left my car there 2 days but can't find the root cause even if there is a code; they said they can't repro it on highway driving. - I might have to pick it up tomorrow without any fix from them.

Case Synopsis: My ownership includes three Hyundai Hybrid vehicles: two 2020 Sonata Hybrids and one 2022 Tucson Hybrid. Each of these cars has consistently manifested engineering defects, predominantly overheating, within a year of purchase. These persistent malfunctions have led to the vehicles being inoperable and beyond repair. As a result, we have endured financial setbacks from negative equity, costs of repairs, reduced value of the cars, and considerable inconvenience and safety hazards due to these ongoing overheating issues.

Case Synopsis: My ownership includes three Hyundai Hybrid vehicles: two 2020 Sonata Hybrids and one 2022 Tucson Hybrid. Each of these cars has consistently manifested engineering defects, predominantly overheating, within a year of purchase. These persistent malfunctions have led to the vehicles being inoperable and beyond repair. As a result, we have endured financial setbacks from negative equity, costs of repairs, reduced value of the cars, and considerable inconvenience and safety hazards due to these ongoing overheating issues.

My car's battery dies 2 or 3 times every week. I have to enter into the the car with the manual key that is inside the key fob then hit the 12v rest button to start my car. I have been to two Hyundai dealerships and they both tell me nothing is wrong. I just picked it up a week a go and it has died twice since I picked up. I see many complaints on reddit about the same issue, even some with car dying while driving. This is a serious that Hyundai needs to figure out.

Starting in July 2023, my car has exhibited a recurring problem that seriously hampers its functionality and reliability. Specifically, the car intermittently fails to respond to unlock commands from both the key fobs and the Hyundai cellphone app. Initially, this issue occurred infrequently, happening about once a month. However, the situation has escalated, and in October 2023, it happened three times within a span of two weeks. I promptly brought my car to my local Hyundai dealership, hoping to find a solution to this perplexing issue. On the first visit, the dealership stated that they were unable to duplicate the issue, which left me deeply frustrated but willing to continue troubleshooting. The dealership suggested that I either leave my car with them overnight or bring it in again for further diagnosis. Due to my reliance on the vehicle for daily transportation, I opted for the latter, bringing my car to the dealership on two additional occasions. Regrettably, on each visit, the dealership was still unable to replicate the issue, leaving me with a vehicle that continues to malfunction. My frustration reached its peak during my last conversation with a Hyundai HQ customer care representative. I expressed my concern and requested that Hyundai cover the cost of a rental car while my vehicle was being examined more thoroughly. However, the representative refused to accommodate this request unless the issue was identified as warrant-able. This response left me feeling unsupported and unheard. I would like to emphasize that I have diligently documented the recurring issues with my Hyundai car, even providing video recordings of the last three incidents to demonstrate the problem's severity and consistency. Despite my efforts, Hyundai has chosen to close the case with no resolution, citing my refusal to bear the cost of a rental car as the reason.

I went to work at 5 in the morning, I turned the heater for the first time after last winter. I noticed that the heater was struggling to warm the cabin. After 10 minutes driven I got an overheating alert on the dashboard. I pulled over on the freeway shoulder and it started to notice a lot of steam coming from the exhaust and a really strong coolant smell. I waited for the engine to cool down and went back home, I drove for 6 minutes and notice a huge amount of smoke coming from the exhaust I pulled over agin on the freeway and waited 20 minutes i finally arrived home and notice the coolant reservoir was empty since the car was burning all the coolant through the exhaust. I went online and saw many many people with Hybrid sonatas complaining about the same issue. This should be a massive recall many of the customers complaining had 20 to 50 thousand miles on their vehicle. This is definitely a safety issue. I’m glad my wife wasn’t driving that day cause the freeway only has two lanes and the shoulder is extremely narrow. Please do something about it, I already called the dealership to make an appointment since my car is still under the extended warranty. If you need more information feel free to contact me.

I have a 2020 Hyundai Sonata limited, recently at 68,089 miles on the odometer my wife was driving and got an engine overheat light and noticed thick white smoke puffing out the exhaust pipe. I told her to pull over when she called me and have it towed to the dealer. Soon after I went to the dealer to look at it because they were saying it would be weeks before they could look at it, and I noticed the coolant reservoir was empty. So, I filled up the reservoir and took it home. Over the next few weeks of driving I noticed the same puffs of white smoke coming out the exhaust every so often and the coolant reservoir draining in a couple days, even though there never was any visible leakage under the car when it was parked. So after a couple weeks of having to top off the coolant every other day I took it back to the dealer and told them what was happening. They were not sure what to do, after a week of troubleshooting they ended up replacing the whole muffler assembly under warranty to fix the issue. So far that seems to have worked. I'm reporting this, because I want NHTSA to investigate these models Hyundai Sonata hybrids 2020-2023 and get Hyundai to engineer a recall solution to this issue, because there seems like hundreds of stories on the internet of people having the exact same issue with these car models. I'm not sure replacing the muffler is a long term solution, unless the replacement mufflers were redesigned. If they are replacing them with simply a new muffler, with the same design flaws as the original I think it will likely fail again just like the original. My car is now at 70,800 miles and the issue seems to be fixed, but I have read many stories on the internet of people having 2 or 3 muffler assemblies replaced on these vehicles and the issue continues to reoccur.