2020 Hyundai Sonata electrical system problems

“My 2020 Hyundai Sonata has a recurring electronic system malfunction that causes multiple dashboard warning lights to illuminate, including the Forward Collision-Avoidance Assist System warning. When this occurs, the vehicle can suddenly lose the ability to accelerate. Most recently, this happened while driving in rainy conditions, creating a serious safety hazard. The vehicle has undergone multiple unsuccessful repairs at Hyundai dealerships, including an extended four-week repair involving Hyundai's technical specialists in 2025. The same problem has now returned, and I am concerned about the vehicle's safety and reliability.”

“A/C blower motor fan would stop working. Happened twice within less than a year apart. Upon further inspection, multi fuse wiring overheated and melted, ruining fuse and making A/C stop working during 100 temperatures outside. Apparently this is a well known issue with this make and model Sonata. Electrical failure.”

“I am submitting a safety complaint regarding a recurring, unresolved electrical defect in my 2020 Hyundai Sonata SEL. The vehicle fails to recognize when the ignition is switched off, leaving core vehicle systems active and causing severe parasitic battery drain that leaves the car immobilized. ​Description of the Problem: ​False "On" Status: After parking, turning off the engine, and exiting the vehicle, the car continues to register as though the ignition is still active/on (accessories, cluster, or vehicle network remain awake). ​ Severe Parasitic Draw: Because the vehicle fails to shut down its electrical circuits, the 12-volt battery repeatedly discharges overnight or while parked for short durations. ​Battery Replacement Did Not Resolve Issue: The 12-volt battery was replaced with a brand-new unit to eliminate typical wear, yet the drain and false "on" behavior persisted immediately. ​ Frequency: The vehicle frequently fails to start, requiring constant jump-starts or roadside assistance to operate. ​Safety Hazard: This defect creates a direct safety risk by repeatedly stranding the driver without warning in public locations, traffic stops, or remote…”

“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.”

“Blower motor malfunction at night. Smelled something burning. Extremely hot and humid outside. Windows fogged up inside which greatly reduced visibility. Checked the multifuse which controls the ABS, oil pump, cooling fan, & Blower. I discovered a burnt connection on one of the terminals for the blower. This is a huge safety and fire risk and needs to be addressed ASAP!!!! Upon my research, I’m finding several Hyundai Sonata vehicles having this same exact issue. Kia vehicles are being recalled for this same exact issue. Why isn’t the Hyundai Sonata??”

“The AC/heating blower motor circuit on my 2020 Hyundai Sonata failed intermittently due to extreme electrical resistance overheating and melting the terminal pins inside the engine fuse box. I took it to the dealership and they inspected it said it was out of warranty but it needed part number 18980-09910-FFF and wiring kit 91300L1000-FF to repair at a cost of 780.00 including parts, tax, and labor. This matches the severe design defect acknowledged in Hyundai TSB #25-EE-002H or alternative TSB-24-EEOO-1H. I filed case number 43138757 with Hyundai corporate. For now this just affects my air conditioning. However, the root failure is a known design defect that presents a severe vehicle fire hazard and potential loss of windshield defrosting capability, lights, etc. if the whole electrical system should fail. As you should know the engine bay fuse box (which currently has melted parts) is the "brain" for the car's electrical distribution. It doesn't just power my AC fan; it holds the fuses and relays for the cars fuel pump, engine control module (ECM), headlights, and electronic power steering. If left unfixed and over time as the plastic melts, copper wires will…”