2020 Hyundai Sonata problems

Filed Nov 2, 2026 · Driver assistance, Electrical · UT

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.

Filed Oct 23, 2026 · OH

My car is showing the same issues as the recall 271 campaign 24V‑879 but my VIN is not included in the recall. My reverse camera is showing a black screen with the guidelines when the vehicle is put into reverse

Filed Oct 19, 2026 · Fuel system · NJ

The car has strong fuel smell in the cabin when tank is full, It is especially strong after car sits. I have taken to hyundai several times for this problem. They say the computer says nothing is wrong. They refuse to investigate as they dont smell the odor.

Filed Oct 16, 2026 · Body · FL

Upon arriving home I noticed that the paint was missing from the back passenger side & when I left the parking lot before heading home there was no paint missing.

Filed Oct 15, 2026 · Brakes, Engine · KY

Vehicle experienced intermittent, severe powertrain defect resulting in a critical safety hazard. Between 30K and 36K miles, the vehicle underwent 3 violent highway deceleration episodes. During these events, the engine began shaking, escalating to violent shaking; with deceleration and coming to a stop, it would shake, then sputter as if it would die. Coming to a complete stop, a total stall was prevented only by the ECM forcing a limp mode lock at 1200 RPMs. When Auto Hold was engaged at this point and my foot was removed from the brake pedal, the mechanical surge caused the vehicle to unexpectedly lurch forward, fighting against and nearly overriding the factory Auto Hold braking safety feature before finally holding. Luckily, no pedestrian was walking in front of my car when this occurred. No check engine light (CEL) or dashboard warning ever illuminated. This safety compromise is directly tied to an ineffective or adjacent remedy involving Service Campaign 9B1 (Opcode 40D219R0) and Safety Recall 286. Under this Opcode, a factory software flash deleted the standard OBD-II trouble code P0451and substituted it with a manufacturer-specific shadow code P14EE00. This software manipulation suppressed universal emission/pressure sensor faults, masking a volatile physical defect within the high pressure fuel delivery and ignition systems. Dealer diagnostics on a running, compromised engine flagged an improper fuel injector pulse and subsequently a failing Cylinder 3 ignition coil. All four injectors were replaced but only one coil, leaving 3 non-updated , factory defective coils in the engine. The vehicle remains an ongoing highway stalling and brake-override hazard due to an incomplete field remedy of a recall-adjacent system. I've filed a Hyundai Complaint with assigned case number 43394228 regarding Safety Recall 286. (Two episodes of the attempted Auto Hold override occurred - first 09/09/2026 and second 09/29/2026.)

Filed Sep 7, 2026 · Electrical · AR

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.

Filed Sep 3, 2026 · Engine · NC

The A/C evaporator core and the core seal needs replacing on 2020 Hyundai Sonata. Car is 6 years old. I already have a confirmed diagnosis with a PPM refrigerant leak tester at the condensate drain line The diagnosis is 100% confirmed. The evaporator is leaking heavily—we pulled 274 PPM at the drain tube and 177 PPM inside the cabin behind the glove box so refrigerent has been leaking out of the vents. My wife and I were getting headaches for no reason. Our AC has failed and this problem was discovered as the issue and I am paying out of pocket to fix something that should not have failed and has leaked out refrigerent.

Filed Sep 3, 2026 · Electrical, Transmission · TX

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 areas. In addition, an electrical system that fails to enter a sleep state creates a potential hazard for component overheating, failure of electronic security and locking systems, or total electrical failure while attempting to restart or operate auxiliary safety equipment. Other Hyundai owners have reported identical issues where the body control modules or ignition logic fail to power down. ​Corrective Action Requested: I request that the federal safety agency investigate this electrical shutdown defect across the 2020 Hyundai Sonata model year to identify whether a faulty Body Control Module (BCM), smart key receiver, or ignition switch relay requires a safety recall and software or hardware remediation. Battery replaced on 09/04/2026 Car inspected/diagnosed by Hyundai Dealership on 09/03/2026

Filed Aug 26, 2026 · Brakes, Driver assistance · NC · crash

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.

Filed Aug 23, 2026 · Driver assistance · AZ

The reverse camera only shows a black screen and will put drivers in danger while not being able to see behind them while reversing. This needs to be recalled and repaired. Especially in situations where a person is reversing out of a driveway onto a major/busy road. Sometimes it works, but a lot of the time it is just a black screen with the green, yellow, and red lines to indicate how far your wheel is turned. But it doesn’t allow you to actually SEE where you’re backing up into or the cars coming from either side of you while trying to back out. It’s very dangerous and it seems to a be manufacturer’s defect that needs to be addressed by the company itself, since they’re the ones who made and installed the product incorrectly.