2020 Hyundai Sonata Hybrid

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.

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.

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 noticed a strange smell almost like burning maple syrup in the garage for months. I thought it was just a different smell from Hybrid cars as I didn't have this used car very long. While driving at times the acceleration would stutter, again I thought this was just expected having never driven a hybrid car. Then on a trip a couple hours out of town someone stopped me on the road to tell me I was burning antifreeze and he could see white smoke coming from the car. I pulled over and didn't notice anything and continued driving but the heater wasn't working, it was blowing cool air despite the heat being on. I pulled into an auto parts store and got antifreeze in case. And then the overheating alert came on. I waited and filled it up and made an appointment at the dealer. They diagnosed it as a a blown gasket and a bad catalytic convertor and replaced all of that. After bringing it home I continued to lose coolant even with a two mile ride, I went from Max fill to half way between max and min. Clearly the problem wasn't the gasket or the catalytic convertor. Others have shared similar experiences online and had to have many parts replaced. The coolant tank, the EGR cooler (?), etc. I don't know what the problem is but something is wrong with these cars.

I have had the same issue 3 separate times related to the coolant system. The first time happened January 2021. I was driving on the highway and I noticed that when the car switched from electric to fuel a large plume of white smoke came out of the exhaust and then the engine overheating message started. I checked the coolant tank and it was completely empty. I managed to get some coolant in the car and get to my destination. I checked the coolant tank again and all the coolant that had been put in was gone. I immediately had the car towed to the dealer. They found the issue was a leak near the muffler and eventually replaced that and other gaskets. In May 2022, I noticed again that when I switched from battery to fuel on acceleration that there was a plume of smoke coming out of the exhaust and my coolant was very low. Brought to the dealer and they confirmed again there was a leak but this time with the EGR cooler and associated parts. In December 2022, I had just gotten an oil change from the dealer and they gave me a clean check up. The next evening I was on the highway again and I received the engine overheating message. I was able to get to the dealer the next morning after refilling the coolant twice. I provided them with the previous paperwork from the other two fixes. They confirmed again that the leak was happening with the muffler so they replaced more parts. In all I have for over 3 months fixing the same issue. I posted on Reddit to see if others have had the same issue and slowly more and more people with the same model year or the year after are reporting the same problems as seen https://www.reddit.com/r/Hyundai/comments/uhx7lf/coolant_leak_through_exhaust_on_2020_sonata_hybrid/?utm_source=share&utm_medium=web2x&context=3 Every time it's happened it's been covered under warranty but my concern is that it happens outside of the warranty and I will be on the hook for an expensive repair or forced to a new vehicle.

Check engine light came on and I contacted the dealer. Took 6 weeks to get an appointment and they advised that a module needed to be replaced giving me the impression it was a computer chip. The car has been sitting at the dealer since February 22, 2022, and they have been very cooperative including providing me with a free loaner to use. Unfortunately, they state that the part is not available (#HY25600-2J001 Thermal Management Module). Finding that this is not a unique failure as it is appearing inn 2020, 2021 models as well as some 2022 Hyundai models. Finding OEM part for sale on EBay, Amazon and even on the Hyundai parts website.