NHTSA Owner Complaint Log
This page lists owner-reported complaints filed with NHTSA for the 2021 Hyundai Sonata. Complaints are unverified consumer reports submitted to NHTSA and do not by themselves prove a defect or defect rate.
Data synced from NHTSA on May 4, 2026
The contact owns a 2021 Hyundai Sonata. The contact stated that while the vehicle was at an independent mechanic for an oil change, the mechanic diagnosed the vehicle with transmission fluid leaking from the engine. The mechanic informed the contact that the transmission fluid leakage was flammable. The dealer was made aware of the failure but informed the contact that they were backed up with other vehicles and could not diagnose the vehicle for approximately three weeks. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was 5,600.
We received a letter back in Dec 2021 about a recall for our windshield that Hyundai was aware of but there was no fix available. It states that if in a crash it could be real bad because the adhesive on the windshield. However i don't think it should take almost 5 months for a serious recall like this.
The contact owns a 2021 Hyundai Sonata. The contact stated that while traveling at highway speeds, a tiny pebble hit his windshield which caused a minor ding on the middle of the driver’s side windshield. Over time, the ding spread from the driver’s side to the lane assist sensor located in the middle of the windshield. The contact stated that the crack spread vertically and horizontally across his windshield. He stated that the crack had obstructed his vision while driving at various speeds. The dealer was initially notified of the failure and informed him that he had to have the vehicle repaired by a recommended third party. The manufacturer had yet to be notified of the failure. The vehicle had yet to be repaired. The failure mileage was 23,000.
2021 Sonata N LINE NOT EQUIPPED WITH AUTO WIPERS WIPERS INTERMITTENTLY COME ON BY ITSELF WHILE DRIVING. IT HAS COME ON MULTIPLE TIMES WHEN USING MY TURN SIGNAL. WIPES ONCE THEN GOES OFF. HAS ALSO COME ON ONCE WITHOUT THE USE OF THE TURN SIGNAL. SWIPED 3 TO 4 TIMES AND THEN WENT OFF
The contact owns a 2021 Hyundai Sonata. The contact stated while driving 65 MPH and attempting to accelerate, the vehicle failed to respond with the check engine warning light illuminated. The contact also heard a knocking sound coming from the vehicle. The contact pulled over on the side of the road and turn off and restarted the vehicle and the vehicle started operating as designed. The vehicle was taken to the dealer and the contact was informed that the transmission and engine needed to be replaced. The manufacturer was contacted but offered no assistance. A case was filed. The failure mileage was 2,700.
On August 23rd, 2021, I was on a business trip between High Point, NC and Greenville, SC. I was operating my own vehicle as the mode of transport. Upon arrival in Greenville, the car began behaving strangely. The transmission was not shifting at typical intervals, at times racing the engine at low speeds. After restarting the vehicle, there was a brief return to normal. Then the vehicle reported a "Check Engine" light and the transmission stopped functioning entirely. Due to capacity issues, I was unable to utilize a local dealership. I used AAA to tow the vehicle to Fort Mill Hyundai in Fort Mill, SC, where it remains to this day. The vehicle threw a P0868 code, which is supposedly a generic error relating to an electrical problem in the transmission.
My transmission went bad on my new car. Didn’t have my car for 4 month August 12 2021
I leased a 2021 Sonata, and the Car has been a nightmare. My Car has been serviced by the dealership twice for a steering wheel that will not stop making noises. I am very concerned for my safety in this Car. The Wheel becomes hard to move. Also, last year, the Car was in the shop for four months while the forward collision sign needed to be fixed. The Car stopped twice. I am terrified to drive this car; it only has 9,200 miles.
WE LEASE A 2021 SONATA SEL EQUIPPED WITH AIR BAG SYSTEM FEATURING AN OCS IN THE RIGHT FRONT SEAT. THE PURPOSE OF THE OCS IS TO DISABLE RIGHT PASSENGER SEAT FRONT AIR BAG WHEN IT DETECTS TA CHILD RESTRAINT SYSTEM OR SMALL CHILD IN THE RIGHT FRONT SEAT. RIGHT FRONT AIR BAG IS DISABLED TO PREVENT INJURIES TO A CHILD FROM A RIGHT FRONT AIR BAG INFLATION DURING A CRASH. MY WIFE IS ABOUT 4'10" TALL AND WEIGHS 135#. WHEN SEATED IN PASSENGER SEAT, SHE REQUIRES A CUSHION TO RAISE HER SO SHE CAN SEE OVER DASHBOARD AND OUT SIDE WINDOW. OUR SONATA IS EQUIPPED WITH MANUAL PASSENGER SEAT THAT IS RAISED TO HIGHEST POSITION. PROBLEM IS THAT WHEN SHE USES CUSHION, THE OCS LIGHT STAYS ON INDICATING THAT AIR BAGS ARE DEACTIVATED AND WOULD NOT DEPLOY IN AN ACCIDENT WHICH COULD CAUSE AN EXTREME SAFETY HAZARD TO MY WIFE. WE TOOK CAR TO DEALER SERVICE CENTER TWICE, AND WE CALLED HYUNDAI USA CUSTOMER SERVICE - BOTH SAID NOTHING COULD BE DONE. SMALL ADULTS LIKE MY WIFE SHOULD BE ABLE TO BYPASS THE OCS USING A SHUNT OR BYPASS SWITCH. WE FEED THIS IS A SERIOUS SAFETY HAZARD. EARLIER SONATA MODELS WERE RECALLED FOR THIS ISSUE.
The contact owns a 2021 Hyundai Sonata. The contact stated that after driving out of the garage and parking in the driveway with the engine idling and remote smart parking assist feature activated, 6 minutes later the vehicle suddenly began to slowly roll forward into the garage area making contact with a second vehicle that was parked in the garage before crashing into the back of the garage wall and stopping. During the incident, no injuries were reported, and no police report was filed. The vehicle was taken to the local dealer who was unable the duplicate the failure. The manufacturer was also notified of the failure. The approximate failure mileage was 1,400.
Excessive wind noise is coming from the driver side window when speeds are over 55mph+. A lot of other owners on the forums are experiencing the same problem.
PANORAMIC SUNROOF EXPLOSION. HAPPENED ON OPEN HIGHWAY ROAD WITH NO CAR IN NEAR VICINITY OR SIGN OF ANY KIND OF DEBRIS HITTING THE VEHICLE.
SEEMS TO BE AN ISSUE WITH THE WIRELESS APPLE CAR PLAY. REGARDLESS IF THE VEHICLE IS IN MOTION OR NOT IT LOSES CONNECTIVITY. WHILE DRIVING THIS CAUSE YOU TO TAKE YOUR EYES OFF THE ROAD AS MESSAGES APPEAR ON THEIR INFOTAINMENT SYSTEM. CALLS ARE DROPPED, NAVIGATION STOPS SO WHILE YOU ARE LOOKING AT THE MESSAGES YOU'RE NOT PAYING ATTENTION TO THE ROAD. APPLE IS AWARE BUT HAS NOT RESOLVED IT. HYUNDAI IS AWARE BUT HAVE NOT RESOLVED IT. THE INTERNET IS LOADED WITH ISSUES FOR THIS SITUATION. NOT SURE IF THIS IS SOMETHING YOU CAN ASSIST WITH BUT I'M ASSUMING AT SOME POINT THEIR WILL BE ACCIDENTS BECAUSE WHEN THIS HAPPENS YOU CAN'T USE THE HANDS FREE OPTION AS IT ALSO STOPS WORKING.