2021 HYUNDAI SONATA Electrical System Problems

My 2021 Hyundai Sonata Limited Hybrid 12v battery has started to die randomly. My car is currently with the Hyundai dealer to confirm if this will be a warranty claim. Searching online, I have found other posts of people complaining about a similar issue with their 2021 Hyundai Sonata Hybrid.

Car sits several days at a time. Door locked. 12 volt auxiliary battery goes dead within 60 minutes after driving 60 miles. Happened 6 times in last 6 weeks. Battery is lithium. Dealer looked at car Sept 8. They did cursory check and said my rodent deterrent caused issue. After driving 60 miles. Turned rodent deterrent off. Still have issue. Car resets the 12 volt battery nearly daily. Lithium battery if bad can blow up and cause vehicle fire. Car is parked in car port next to house. If fire, it burns up my house also. This is fire hazard. If the battery is bad, it must be fixed. Car under 10 year 100,000 mile bumper to bumper warranty. I need car fixed. NOT just looked at. This is fire hazard till it is fixed,

2021 Hyundai Sonata with approximately 39,000 miles. On [XXX], the dashboard displayed the following message "Shifter system malfunction! Service immediately" When the warning appeared, the vehicle shifter button would not function, creating a traffic safety risk. History: Dealer service history shows the transmission was replaced on the vehicle under warranty on 08/30/2021 with 2,212 miles with no campaign/recall issued. Dealer states there is no recall campaign on this vehicles specific VIN # and NHTSA currently shows no open recalls for this vehicle. However, Hyundai advertises an 8-Speed DCT Safety Recall for the same year, make and model, and describes this identical issue, but has left this vehicle's VIN# out of scope for this recall, which is continuing to demonstrate the same issues. Current dealer/manufacturer response: On 9/4/2025, the dealer declined warranty or recall repair unless the fault was active on their diagnostic scan at the moment the scan was performed....

The buttons to the door locking and unlocking don't work unless I open and close my door a few times. The same thing with the back windows. But after you do the trick and use the intended button once, it stops working and have to repeat the entire process over again. Which is not safe especially when the car is in motion, I am not able to use those buttons at all.

On 5 separate occasions the car has shut itself off while driving. After the first 2 times the car was taken to the dealership where they found nothing wrong and told us to replace the battery. The battery was replaced by the dealer and within the next two weeks the car shut itself off while driving 3 more times. The car will always start back up again right away. This is a very dangerous situation.

In June 2024, I was driving my vehicle when I started to smell burning from under the dashboard. As I continued to drive, the smell got worse, and on my way to the dealer, my air conditioner stopped working. I took my car back to the dealer for service, and several days later, I was told that my car needed a hardness connected to several components in the engine compartment. I remember while I was dropping off my car at the dealer, one of the service advisors told me that it was good. I drove to the dealer because the car could have gone on fire. It's now six months later, and they have not fixed my car. I was told they're awaiting parts from Korea to complete the fix. My concern is that this part can cause a fire. Why did Hyundai not recall these vehicles? Hyundai knows about...

This car has two problems. 2 weeks I was driving on the highway. All the sudden the shutoff and lost all power on the car. Thank god I pulled to the side of the road safely. Turned the car off and turned it back on. The car started to run normal. I took it to mechanic. They scanned the car with their computer. Said the car has no problems. Tested the battery and all other components. No problems found. This happened again yesterday on the highway driving. Car engine shuts off again. The car has engine problems as well. But Hyundai denies to address it.

2021 Hyundai Sonata 59,850 miles RPM jumps to around 1,300 at zero miles on occasion. If I am stopped, at a red light or behind other stopped autos, the vehicle jumps forward when I take my foot off the brake. Because this happens quite often, I am aware of this and keep my foot on the brake until other vehicles are out of the way to avoid bumping into them. When this happens, I can cruise at 30 miles per hour without having my foot on the accelerator, I can slow down or stop by applying the brakes but the engine RPM stays at 1,300. If I stop and shut off the vehicle and restart, the operation goes back to normal but occurs again later. The Hyundai dealer has had the vehicle back 9 times but the issue continues. The first few times, they could not find an issue, I...

Blower motor on 2021 Hyundai Sonata SEL stopped working. Same issue happened on my 2020 Hyundai SEL and currently waiting on 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.

Fuse box has a defect causing the AC blower motor to intermittently not work. Appears to be the result of loose connections between the fuse box and the fuse itself. The receptacle for the fuse is clearly burnt/melting, and appears to pose as a fire hazard as a result. The car is currently in the shop for repair on this part, but won't likely be fixed for a month+. I do have photos of the damaged parts, should it be requested. The car was taken into a Hyundai dealership for repair work in November 2023, and I was told the fuse had blown but that they fixed it. I was never told about the box appearing damaged/melting at that time, or this being a common problem. It worked again till July 2024. Car was just dropped off 9/3, due to backlog of cars at dealership. The only symptom of issue...

Infotainment center won't switch to Radio. No signal for AM/FM or Satellite. Then HVAC system stopped blowing. No defrost, won't blow heat or AC. Blower motors been tested and works, blower motor resister replaced. Everyone I talk to is saying it's an electrical, connection issue.

So for the past year and half my cars left turn signal has been working intermittently. It just stops working and then it starts again. I have taken it to the dealer many times they changed out signal assembly i have taken many videos show proof. I am told at the dealer if you dont bring it in when it is not working then they cannot do anything even if i have video proof documenting this issue for the past year this is a serious safety issue that must be addressed. My next step is to contact Hyundai directly hopefully you can investigate this issue. This is very dangerous.

After 9 months of ownership, on at least five (5) instances, the car has the following things happen at the same time: 1) all warning lights on the dashboard activate, 2) the battery discharge warning light activates, a loss of power steering, no speedometer, no cameras (rear or front), no AC, and all the safety functions are disabled including but not limited to: Forward Collision Warning, Parking Collision Warning, Automatic Emergency Braking, Lane Departure Warning, Rear Cross Traffic Warning. Yes, the car is available for inspection upon request. Safety is at risk by the loss of power steering and the deactivation of all safety functions. After each instance, the car has gone back to the manufacturer's dealer for inspection, they believed it might be an electrical issue after scanning for fault codes, but after 5 times, the dealer has not yet diagnosed the issue.

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