Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2020 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2020 Hyundai Sonata. The contact stated that while her husband was driving 75 MPH, the brake warning light appeared on the instrument panel as the vehicle began to hesitate upon depression of the accelerator pedal. The contact stated that the vehicle decelerated to 20 MPH as her husband pulled to the side of the highway and turned off the vehicle. The contact called the dealer and was given suggestions on how to correct the failure; however, none of the options worked. After some time, her husband restarted the vehicle and the vehicle resumed normal operation. The next day, the contact stated that the brake light returned upon start of the vehicle. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 19,000.
While stopping at a major highway intersection on [redacted] for a red light vehicle stalls and will not start back up while everyone else continues at a 55 mph mile an hour passing me on each side! This happened more than 6 times . While you're stuck in intersection,you have to keep trying to start the car eventually it will start . Apparently it is EGR valve and is a very common problem. IT IS NOTED IN THE common problem for this year making model and the repair cost is in the range of $1600 even the dealership said it is a very common problem. They have been experiencing it.
The contact owns a 2020 Hyundai Sonata. The contact stated that while the vehicle was parked, the vehicle failed to start as intended. The contact stated that several unknown warning lights were illuminated. The contact stated that the vehicle eventually started and drove normally. The vehicle was then taken to an independent mechanic, where it was diagnosed and determined that the starter needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 27,000.
Parking malfunction. Parked, running car moved itself to reverse and backed up a driveway crossing a dirt road and hitting a fence and post. This car could have hit and severely injured anyone who was in the path while it was reversing on its own. Car was in reverse and all parking sensors were blaring when the car was found minutes later.
I was driving on the interstate when I heard a click from the back of the car. The gas gauge started to move downward as if I was losing gasoline. It eventually stopped and started moving back up, past where it was when it started decreasing. A little bit later the check engine light came on and the car started driving very sluggishly. I took the car into the Hyundai dealer and they found that the backseat was clicked out of place and a sensor was unplugged. This issue has since occurred multiple times. The back seat will pop out of place, the gas gauge will move beyond the gas that is in the tank, and finally the check engine light will come on and reduce the performance of the vehicle. The gas tank appears to be swelling and pushing up against the back seat which is causing it to pop. …
My 2020 Hyundai Sonata SE (82931 miles at the time) has experienced repeated issues with the front passenger window. The window would get stuck while attempting to operate it, accompanied by a loud, crushing noise. Upon visiting the dealership, I was informed that the issue stemmed from the window regulator, which had failed internally and required replacement. Additionally, my girlfriend, who owns a 2020 Hyundai Sonata SEL with approximately 31,000 miles, is now facing the exact same problem with her vehicle's front passenger window. After conducting research on online forums, I discovered that several other 2020 Hyundai Sonata owners are reporting similar issues with their window regulators. This suggests that the problem may not be isolated to just one or two vehicles but could point to a potential widespread defect. …
I believe the transmission malfunctioned as I reached 60 MPH / 4000 RPMs on the highway when it suddenly did not want to accelerate past that. The more I stepped on the gas pedal, the more it slowed down. I attempted to use the paddle shifters to shift up or down, but I was unable to shift up and shifting down did not allow me to accelerate past 4000 RPMs. The flow of traffic was faster than I could keep up with, and not being able to accelerate made it unsafe to be on the highway. I had to pull over, and get off of the highway. I found that others have reported this same issue online with the same make/model/trim, but I have not had time to take it in to be looked at. No warning lamps, messages, or other symptoms prior to failure. I only noticed when I got on the highway and needed to reach speeds greater than 60 MPH. …
Without warning, symptoms of the A/C blower not working first occurred a little over a month ago. The fan just stopped blowing altogether (no cold or hot air). After turning the car and the A/C system on and off several times, it began working again and that was it. This past week, the same issue occurred intermittently over 3-4 days. The A/C blower did not come on for a day, the next morning it was functioning, that evening it stopped blowing again, and this went on for several days. Research of the symptoms via YouTube and many online forums, and most importantly confirmation through visual inspection of the fuse box, confirmed that the BLOWER fuse is burning so bad it has melted the connecting port in the fuse box. Whatever the electrical malfunction, the fuse burning and melting is disrupting the connection and ultimately the A/C blower itself. …
Driving, car started making a weird sound followed by a warning light on dashboard with dinging sound to correlate... car became difficult to gas, vehicle motion was lagging where I just knew I had to pull over Bc this car was going to literally stop began to slowly (Bc that's all car would allow) to proceed forward and I was forced to come to a haunt as I pulled onto side of highway. I then could no longer move it. Turned car off for minute then returned to try to start again, car would not accelerate at all nor turn on fully.. I was forced to wait hour to get a tow... took to shop, no problem such was found , car started & ran again ... this is 3 days later the car again continued the same exact pattern & I was unable to drive any further and forced to once again to get tow. …
Wiring harness under fuse box is not making a consistent connection and is causing the blower amp to overheat and disconnect. When this happen, cabin air doesn't blow and the front and rear defrost stops working. The only way to make the blower engage is by removing the fuse box cover and tapping the 30 amp fuse things. I've taken my car to the dealership for this specific problem 5 separate times, and it was supposed to be corrected. Due to this poor connection, I am now about $1200 into repairs / replacing parts that aren't the root cause. I am not taking my car back to the dealership for a 6th time to have it "fixed" but the service guy looked me in the face and said "you should trade it. We see this issue all the time in sonatas and elantras. It won't be fixed". …
Related recalls
Electrical system › Software
Hyundai Motor America (Hyundai) is recalling certain 2020 Nexo and Sonata vehicles. The Remote Smart Parking Assist (RSPA) software may fail to prevent vehicle movement upon detection of an RSPA system malfunction.
Remedy: Hyundai will notify owners, and dealers will reprogram the RSPA software, free of charge. The recall began June 3, 2020. Owners may contact Hyundai customer service at 1-855-371-9460.
Electrical complaints in other Sonata years
Frequently asked questions
How common are electrical problems on the 2020 Hyundai Sonata?
NHTSA has 40 complaints about the electrical system of the 2020 Hyundai Sonata, 22% of the model year's 181 complaints. The component named most often is starter assembly (1 mentions).
Is there a recall for 2020 Hyundai Sonata electrical problems?
Yes — NHTSA recall 20V-213 (software, Apr 9, 2020). Recall repairs are free at authorized dealers.
At what mileage do 2020 Hyundai Sonata electrical problems start?
Half of the complaints with a recorded mileage happened before about 19,000 miles, and 83% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 0 injuries to electrical system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.