Wiper problems of the 2021 Hyundai Sonata

The internal core of the exhaust heat recovery system (ehrs), part of the center muffler/front pipe assembly (#28600-l5210), suffered a catastrophic failure. This allowed approximately 9 gallons of engine coolant to leak directly into the hot exhaust stream. Safety risk: this failure creates a severe visibility hazard. During acceleration from stop lights and stop signs, the vehicle emits massive, thick clouds of white glycol smoke. The smoke is so dense that it completely obscures the driver's view of trailing vehicles and prevents following drivers from seeing the roadway or my vehicle's brake lights, creating a high risk of rear-end collisions. Additionally, the rapid loss of coolant caused the engine to overheat and lose power while in motion, nearly causing a stall in active traffic. Confirmation: the failure was confirmed by the service department at washington Hyundai (invoice #174281). This is the second failure of this specific component (previously failed in Jan 2025). The manufacturer issued TSB 23-em-009h for this defect, acknowledging it affects 2020-2023 Sonata hybrids, but no safety recall has been issued. Symptoms: the issue was preceded by a "sweet" burning smell and a sudden "engine overheating" warning on the dashboard. The failed component has been replaced by the dealer, but the manufacturer refused to replace the coolant-poisoned oxygen (O2) sensors, leaving the vehicle in a technically compromised state. The failed unit is likely held by the dealer for warranty parts return.

The ehrs coolant system failed and had a leak causing the coolant to be excessively burned off as thick white smoke. This caused me to not be able to see anything behind me and forced others to stop or slow down dramatically to avoid colliding with me. I had my engine overheat and force me to pull over on the side of an unsafe road because the exhaust system burned off my entire tank of coolant in less than a mile. I have taken this to a Hyundai dealership and they confirmed it was the ehrs system failure and told me it was a fairly known issue with the 2020-2023 Sonata hybrids. I was told that even if I get it replaced the possibility of having it happen again are pretty high. This seems extremely unsafe to myself and others.

The vehicle's hvac (heating) system failed. It stopped producing heat on one side of the vehicle. My mechanic/dealer diagnosed the issue as a broken component within the hvac case under the dashboard, requiring full dashboard removal and a repair estimated at over $3,000. This failure prevents the defroster from working properly, which is a major safety hazard as it cannot clear fog or frost from the windshield. A search of online forums and owner communities shows this is a widespread complaint from many other Hyundai owners, often identified as a failed blend door or blend door actuator, which requires the same expensive dashboard removal to repair.

The vehicle, after parking, is nonresponsive to the key fob, nor will it start. This can happen at anytime and anywhere. Dealer said "it is possible the integrated 12v battery into the hybrid battery may be faulty. No codes or tests can confirm the issue. The dealer said the key fobs tested ok. " my wife works late at night in a dark area, this has happened 2 times at her place of work and we are concerned for her safety as she has to wait outside for a tow truck to tow it to the dealer. The first 3 times it occured, this issue started around March of 2024, and repeated every 30-45 days. Now it has happened 2 more times in the last week. No warning lamps or indications of problems. The windshield has distortion within the glass and is not a clear view. It is as though you are looking through the heat of a jet engine trying to focus on what is on the other side. This is a major distraction while driving, reading the heads up display in the car, reading street signs and general navigation of pedestrian and other vehicle traffic. There is no aftermarket film or materials on the windshield. The door handle on the drivers side has a cover plate over the hole where a manual key could be inserted. As a construction worker I have very strong hands and I have a difficult time removing the cover plate. The last time I removed the plate I cut my hand on the interior part of the handle as the cover plate popped off. That is how hard the plate is to remove. My wife cannot remove the cover plate on her own. This system is in place for the manual use of the hidden key inside the key fob to be able to open the door in the event of a power failure of the vehicle. Which has now happened randomly 5 times.

My car barely has 11,000 miles and just the other day it had about 20miles left of gas but as I was driving on the road it started to feel and seem like it was about to die on me, also the front wipers are not well restrained with the vehicle you can tell by the way it moves when wipers are on. . . . Also most of the signals be it if something is in front of me and the signal goes off but theres nothing there . . . Also when im backing up sometimes the car itself will force stop as if something is in the way . . . But again nothing is there at all . . . It happens every few days . . . . I just purchased this car . . And really thinking it was worst mistake w all these issues already.

Front sunroof panel exploded toward while the car was running, but in the driveway in park. Safety was compromised by the shattered tempered glass falling into the car. Problem was noted at the dealer, who stated they had not seen this happen before and believed it to be from a rock chip. Roof has been inspected by the service department at the dealer, and pictures taken by them and by me. It has been reported to the manufacturer. Problems noted prior to the “explosion”. Sitting in my car on a cold 27f morning, I started the car and turned on the front and rear defrosters and the heater. There was a light dusting of frost on the car. About a minute after I started the car, I heard a loud bang above me. When I opened the sunroof cover to see what the noise was, tempered glass shards fell in on me. When I got out of the car to see what had happened, the roof appeared to be exploded outward in circle about 10” across, although most of the sunroof glass was “crazed”. The car was not moving, had not had time to get warm, inside, there was no tree or other environmental hazard close to drop on the roof.

Recall on my vehicle states there is still no remedy after one month.

2021 Sonata n line not equipped with auto wipers wipers intermittently come on by itself while driving. It has come on multiple times when using my turn signal. Wipes once then goes off. Has also come on once without the use of the turn signal. Swiped 3 to 4 times and then went off.

Panoramic sunroof explosion. Happened on open highway road with no car in near vicinity or sign of any kind of debris hitting the vehicle.