2020 Hyundai Sonata Electrical System Problems

The back up camera sometimes is only a black screen, it is random and has done it in all sorts of weather. Usually is corrected when vehicle is started next.

I have taken my vehicle to a certified Hyundai dealership multiple times due to intermittent starting issues. The car will unlock remotely, and the lights and electrical components will turn on, but the engine will not start. When this happens, I press the ignition button to turn the vehicle off and then try again. Sometimes it eventually starts, but there have been several occasions when it would not start at all, forcing me to call for a tow or have the battery jumped. This issue occurs most often in cool or cold weather. I had a brand new battery installed at the dealership in July 2025, yet the problem has continued. I have been dealing with this for over a year and have even been stranded out of state in below-freezing temperatures. Each time I bring the vehicle in, the dealership states they are unable to replicate the issue while it is in their service department.

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.

While stopping at a major highway intersection on [XXX] 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. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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. In the dead of such a hot and humid summer, it has been insufferable having to ride around with such inconsistent and intermittent air conditioning.

The HVAC blower motor and related electrical components (including the fuse box, wiring harness, or control module) have malfunctioned. The system either fails to operate entirely or works only on low, with unpredictable surging airflow. These components are still installed in the vehicle and available for inspection upon request. For the past five days, my family has been driving without a functioning air conditioner in extreme Oklahoma summer heat. This is not only uncomfortable but unsafe, especially for my young child who regularly rides in the vehicle. In addition, without reliable airflow, we are unable to defog the windshield in humid conditions, which significantly reduces visibility and increases the risk of a crash. The inability to regulate cabin temperature and airflow poses a serious safety hazard. Yes, the issue has been observed by the dealership during service visits. However, Hyundai has denied goodwill repair assistance and has not formally acknowledged the defect, despite Technical Service Bulletins and numerous similar reports from other owners. Yes, the vehicle has been inspected by an authorized Hyundai dealership as part of a multi-point inspection. No warning lamps or dashboard messages appeared. However, symptoms began nearly a month ago and have persisted, including intermittent blower operation, limited airflow regardless of settings, and occasional surging. While I have not personally noticed a burning smell, I’ve found numerous reports from other 2020–2021 Sonata owners describing complete blower failure and smoke smells, often tied to fuse box or electrical issues.

The ac blower keeps going out I looked it up and a lot of people are having the same problem my ac keep having to buy blowers and they last 1 week before they stop working and they are not cheap my blower keeps going out and my electric in my car keeps messing up when I try to put the ac up it goes up then goes down I don’t know what’s wrong but I looked it up and a lot of people have the same problem

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”. I’ve replaced the blower motor, had the Freon charged, this is one of the vehicles with the exploding gas tank, and I’ve already paid to replace gaskets.

My Passenger window fell down and will not go up, It is available for inspection upon request. Safety Risk is that the window is being help up by tape and if it falls all of a sudden while driving could break the glass and spread inside as well as cause object to fly out of the vehicle. This has not been inspected by the manufacturer or anyone No warning lamps or messages. I put my window down and then it never went back up and motor was just running and probably made it worse

Multi fuse controlling the A/C blower has burned out 3 times in the past year.

Blower motor stopped working. Same issue has now happened on my 2021 Hyundai Sonata Limited. I have been waiting now three months to have my 2020 Sonata to be fixed. Hyundai technician said the wiring harness had a crack and it’s why my 2020 Sonata’s Blower motor stopped working. It’s now three months since they diagnosed and ordered the wiring harness but supposedly it’s still on back order and I’m left with a hot car this entire summer and possibly a cold car come this winter. Now it looks like I will have the same issue with my 2021 Hyundai Sonta Limited leaving me with two cars without A/C or Heat.

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. I had my girlfriend drive the car while I sat in the backseat and I could actually feeling something moving underneath the backseat. I have since gotten in contact with other sonata owners who have had the same thing happen with their vehicles. In other cases the backseat has exploded and flown completely off of the gas tank. I am very nervous to drive my car and think Hyundai should recall these vehicles before someone gets hurt.

Improperly seated strip fuse High Resistance Connection on the IG-2 40amp blower motor fuse receptacle causing melting of plastic fuse box components and ultimately failure of blower motor circuit and potentially loss of other circuits. Loss of blower motor leads to loss of cabin HVAC as well as loss of front windshield defrost ability during adverse driving conditions. Not only does this pose a potential electrical fire hazard, but a safety hazard due to inability to clear windshield from loss of defrost feature. Brief research finds this to be a very common problem with these vehicles. Manufacturer's recommendation is complete replacement of engine bay wiring harness. Problem begins as intermittent, but leads to total circuit failure over time if not identified.

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. Although this issue primarily affects the operation of the window, it could lead to safety risks if the window gets stuck in an open position, exposing occupants to potential theft, weather elements, or other hazards. I am requesting the NHTSA investigate this matter to determine if the window regulator failure in 2020 Hyundai Sonata models is a systemic defect that warrants further action, such as a recall or manufacturer response. I am happy to provide additional information or documentation, such as repair invoices, dealership statements, or records of the issue. Thank you for addressing this concern.

Defrost doesn’t work because harness melted and blew a fuse

While driving my cars a light starting blinking and my engine light came on and the car lost power This has happened on at least 3 occasions and I had to pull over upon starting the car after a few hours all returned to normal I reported this to dealer and they could not find a problem

The AC Fan in my car quit working. Took it to a repair shop where I was told that the AC Blower Motor went bad. The blower motor was drawing too much amps and caused the blower motor fuse to melt into the wiring harness for the blower motor along with melting several other fuses nearby including the fuse box. The cost to repair this correctly fixing and addressing all parts damaged was $5000. Because my vehicle is out of warranty due to mileage I contacted Hyundai who stated that I had to go and pay another diagnostic fee at a Hyundai Dealership to have them look at it. They continued to tell me that the vehicle was out of warranty but would not assist in providing information to get the issue resolved at no cost to me.

I first begin having an issue with the idle speed. It would jump up to 1,500 RPM, which is twice the normal 750 RPM level It started almost from the very beginning when I purchased this car new in early 2020. I mentioned it at first oil change at dealer at 3,500 miles. I was told it was normal. In the beginning it would come and go. Sometimes not happening for weeks in-between episodes. Then it started to have the check engine light come on after it would happen and stay on. I took it back while light was still on and they kept the car for several days. Said it was the EPV valve and replaced it. Car operated fine for a few days then started up again. It also started to idle up and down from 1500 down to 500 in a rapid succession. I was able to get it to stop sometimes by turning engine off and them back on. Again I contacted dealership and took car back in. They gave me a loaner car and kept my car for over a month. This time they replaced the computer they told me. I did not have car for more than a week before it started doing it again. It has gradually gotten worse and happens more often now. It has also started to have the Forward Collision Avoidance warning come on in addition to check engine light as well. Just this week it actually just died on me while driving and forced me to pull to side of road. Turn off the engine and restart the engine. This happen 3 times in succession. Dealership does not seem to have any idea on what is going on and have been not very helpful. 3 week wait to get an appointment to bring in and no loaner cars available. This problem with the 2020 vehicle is very dangerous. It can idle up at anytime and car will lurch, requiring forceful brakeing . Car dying while driving and losing power as well.

I took my vehicle into the dealership when it was under 12,000 miles for another issue and mentioned a problem with the headlight on the right fogging up with moisture. I was immediately told that this had to be seen with their eyes because light cost more than $1,000. It has continued for over 1 1/2 years. Early this month, I took a picture at night and in the morning. The service manager wanted to add another hoop; can you get a picture of the water in it? The water is droplets on the light, decreasing visibility on the road. Pictures are attached. There is one picture that shows the left headlight with no issue.

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. This has to be something of bearings with engine, this car mode is not on list but IT certainly is an issue that I believe is related & should be rectified by Hyundai.