How many problems does the 2021 HYUNDAI Sonata have?

The 2021 HYUNDAI Sonata currently has 89 owner-reported complaints according to NHTSA database. These complaints are organized by component to help identify common issues.

What are the most common problems with 2021 HYUNDAI Sonata?

The most common problems reported for the 2021 HYUNDAI Sonata are organized by component above. Each component section shows owner-reported issues, crash reports, and fire incidents to help identify patterns and problem areas.

Where does this 2021 HYUNDAI Sonata problem data come from?

All problem and complaint data for the 2021 HYUNDAI Sonata comes directly from the National Highway Traffic Safety Administration (NHTSA) database. These are real complaints submitted by actual vehicle owners.

2021 HYUNDAI Sonata Problems

UNKNOWN OR OTHER

18 complaints

The parking assistant camera on the front of the car is loose, which means that the bracket is broke. I took my car into Hyundai and they could not explain to me how it got broke or came loose and this is a safety issue because this helps you park and see what’s in front of you when parking.

Sep 05, 2025

I am writing to formally file a complaint regarding Hyundai’s Recall Campaign 216, which involves a safety defect related to the windshield assemblies of certain Hyundai vehicles. Despite the recall being issued to address the risk of inadequate windshield adhesion due to non-conforming clear coat paint, I have been unable to get my vehicle repaired. I contacted my local Hyundai dealership promptly after learning about the recall; however, they informed me that they were unable to perform the repair at the time due to not having a glass technician on staff/on site. I made multiple phone calls after anticipating the service manager’s follow up, as she promised, with dates a glass technician could be on site. I never heard back after leaving various voicemails or being put through to the wrong departments. This delay is concerning because the recall notice specifically outlines the increased risk of injury in a crash if the windshield is not adequately retained. As a concerned vehicle owner, I am left driving a potentially unsafe vehicle without any clarity on when a proper remedy will be available. I urge the NHTSA to investigate this matter and ensure that Hyundai and its dealerships are prepared and properly equipped to carry out the necessary recall repairs in a timely manner, in alignment with their safety responsibilities. I have attached the email received 7/31 from Hyundai following my customer service complaint I submitted 7/9. Please let me know if any additional documentation or vehicle information is required.

Aug 06, 2025

The moon roof made a very loud noise as I was driving down the interstate. It sounded like a loud bang. The safety risk was that I could have jerked the wheel from the scare of the loud sound. My moon roof then shattered and began to fly off.

Jun 23, 2025

Rearview camera fails to display an image. It does work sometimes but then most of the times the rearview camera does not display any image as seen in the images attached. This issue started occurring recently, that is when I reverse the car, the rearview camera image is not displayed at all. Earlier the rearview camera was working with out any issue when I reverse the car. Issue seems to be same as campaign number: 24V879000

Jun 18, 2025

P0741 code tcc solenoid

May 25, 2025

+ 13 more complaints for this component

POWER TRAIN

12 complaints

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at 30 MPH and depressing the accelerator pedal, the vehicle failed to respond and lost power. The vehicle was coasted over to the right side of the road, turned off, restarted, and returned to normal functionality. An independent mechanic was contacted. The vehicle was taken to an independent mechanic to be diagnosed; however, the diagnosis was unknown. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 22V746000 (POWER TRAIN); however, the VIN was not included in the recall. The manufacturer was not notified of the failure. The failure mileage was 35,000.

Oct 27, 2025

My transmission on my 21 Hyundai sonata n line has failed. It began when the car needed to emergency brake when someone jump into my lane on the road. There’s grinding, and whining in the transmission along with delayed shifts, jerking and a burning smell that comes through the vents of my car upon start up. The recall on this transmission is because it may become defective. I bought the vehicle from a Honda not a Hyundai dealer in March of 2023 the recall campaign closed out Jan of 2023. According to Hyundai records show that the TCU update remedy was performed Jan of 23. However, even though that TCU update was performed, 2 years later my transmission began to fail. I brought it to my local dealer for a transmission drain and refill not a flush. Per the service manual it’s a drain and refill however they flushed it which caused the transmission to worsen. I took it back to have it diagnosed and I was told I needed my transmission replaced. Didn’t even explain why or go into further detail what was wrong with the transmission. I brought up the recall on the transmission and they did nothing to honor it. Now I’m stuck with a car with a broken transmission i can’t afford to fix and I’m gonna be forced to hand the car over to the bank. If this recall can still be honored please help.

Mar 11, 2025

2 years after purchasing a new vehicle, the transmission began to pop and cause the car to jerk upon a cold start, RPM would increase but the speedometer would not go over 20mph. There were no error messages or alerts. I reported it several times, and the dealership technicians could not duplicate the issue and stated that the car was driving as it was designed even after providing video proof. They were later able to partially replicate the issue when the car popped and jerked after a cold start and then replaced the transmission, however, it did not resolve the issue. 1 month after the repair the car started having the same issues. After several trips to the service department, they have still been unable to duplicate the issue even with recent video proof. Based on how the technicians enter notes, the manufacturer refuses to pursue any alternative method for figuring out what is going on. This is risky because my car, upon starting cannot be safely driven and the car will shutter upon stopping at lights sometimes.

Jan 05, 2025

Issue with DCT transmission. Unknown remedy

Aug 09, 2024

I took off from the house about 1 mile the car stop in the middle of the road with no warning, lights or anything. Thank God I didn’t get an accident we took the car to the dealer and the dealer telling us it’s not covered by warranty. This is 2021 Hyundai sonata lease with only 44,000 miles my wife is so scared to driving Hyundai anymore. We talk to the dealer they don’t give us loaner car still one week from now they are telling us to pay $13,000 for the repair.

Sep 23, 2023

+ 7 more complaints for this component

ELECTRICAL SYSTEM

9 complaints

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.

Nov 18, 2025

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,

Oct 21, 2025

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.

Apr 30, 2025

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 the problem. I was told that I'm not the only one waiting; supposedly, there are 100's more customers waiting for this part.

Dec 23, 2024

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.

Sep 07, 2024

+ 4 more complaints for this component

ENGINE

8 complaints

I purchased this vehicle brand new. It is still under factory warranty. It has approximately 14k miles on it. I have followed all recommended maintenance procedures. During a routine maintenance appointment at the dealership (Vancouver Hyundai 6802 NE 40th Street, Vancouver WA 98661) they identified a catastrophic engine failure due to internal component deterioration and the engine needs to be replaced. They have had my vehicle in their possession since [XXX] of this year for a total of 134 days. I have a case number at Hyundai # [XXX]. They have not been helpful in providing any information and as of now, I do not know when they even expect to receive a new engine. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Sep 19, 2024

Crash: 1

faulty engine thermostat

Mar 22, 2024

I was on the highway going 60 mph then all of a sudden my vehicles rpm's jumped way up to 8 and completely lost power was on I-45 in Conroe thankfully I was in the slow lane. I have attached pictures of my dash so I could get proof this time. I had to wait 7 minutes for the car to do anything. It also burned all of my engine oil. So had to buy oil for my vehicle. I just had my oil change 3 weeks ago. This has happened before on on the frontage road a few months ago. I have claims open with Hyundai Customer Care. I have been stating that my engine makes a clicking noise, it hesitates, and seizes all the time. I have had this problem since March of 2021 and I bought the car in January 2021. I know I am not a part of the engine recall but I should be. I am scared to drive it. Hyundai doesn't care one bit. Well enough is enough I will be getting rid of this death trap. If you are looking at Hyundai's don't waste your time or money.

Dec 09, 2023

I have a 2021 Hyundai Sonata SEL with a Smartstream 2.5L engine w/ GDI & MPI. I have have always heard a loud knocking noise coming from my engine since I got the vehicle when in park. When you are accelerating it hesitates and you can hear a knocking noise. I have taken it to the dealership multiple times and they were able to feel and hear what I was talking about but ensured me it was fine. Recently it has been a lot worse. On 10/18/2023 I was getting on to the highway from the feeder. I tried to accelerate to about 50 mph and I heard the same knocking noise and my rpms jumped all the way to the top. Then my car suddenly stopped getting on to the highway. It took it about a minute before I could start driving again. Luckily there was no one behind me because it could've been really bad. I got home and looked under the hood and it looked like oil had sprayed out of the engine. You could to see oil splatter on the fender. No one was hurt thankfully. I have been complaining about the knocking and hesitation while accelerating for almost 2yrs.

Oct 23, 2023

The contact owns a 2021 Hyundai Sonata. The contact stated while driving 45 MPH, the vehicle inadvertently lost motive power in the middle of the roadway and failed to restart. The vehicle was pushed to the shoulder of the roadway, where the failure persisted. No warning lights were illuminated. The vehicle was towed to the dealer, who determined that there was no oil in the engine, causing the engine to seize. The vehicle was then towed to another dealer, who confirmed the diagnostic results. The contact stated that an oil change was performed three days prior to the failure. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 44,000.

Sep 25, 2023

+ 3 more complaints for this component

VISIBILITY/WIPER

4 complaints

*The front sunroof panel exploded toward while the car was running, but in the driveway in park. *Our safety was compromised by the shattered tempered glass falling into the car. *The problem was noted at the dealer, who stated they had not seen this happen before and believed it to be from a rock chip. *The roof has been inspected by the service department at the dealer, and pictures taken by them and by me. It has been reported to the manufacturer. *No problems noted prior to the “explosion”. Sitting in my car on a cold 27F morning, I started the car and turned on the front and rear defrosters and the heater. There was a light dusting of frost on the car. About a minute after I started the car, I heard a loud bang above me. When I opened the sunroof cover to see what the noise was, tempered glass shards fell in on me. When I got out of the car to see what had happened, the roof appeared to be exploded outward in circle about 10” across, although most of the sunroof glass was “crazed”. The car was not moving, had not had time to get warm, inside, there was no tree or other environmental hazard close to drop on the roof.

Dec 28, 2022

Recall on my vehicle states there is still no remedy after one month.

Jan 30, 2022

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

Oct 29, 2021

PANORAMIC SUNROOF EXPLOSION. HAPPENED ON OPEN HIGHWAY ROAD WITH NO CAR IN NEAR VICINITY OR SIGN OF ANY KIND OF DEBRIS HITTING THE VEHICLE.

Mar 26, 2021

ELECTRICAL SYSTEM,ENGINE

3 complaints

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.

Feb 12, 2025

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.

Dec 04, 2024

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 returned to the shop when this was happening and the service manager and a technician observed this condition, the EGR valve was replaced. Was OK for a bit but condition returned, the computer was then replaced. Condition continued. Brought the vehicle back and a scan was done and system “re-learned. After a short time the condition returned. Went back to the service center and they did another scan and another re-learn. Condition returned 4-5 days later. Problem still not resolved. Have 59,850 miles on the vehicle, warranty expires at 60,00 miles. This started around July 1, Now October 5. Waiting for a loaner so the service center can drive it around until the situation occurs and they can bring it in immediately for diagnosis. This is the same issue as reported for the same year vehicle in July 2022.

Oct 06, 2024

VISIBILITY

3 complaints

The contact owned a 2021 Hyundai Sonata. The contact stated that while driving approximately 70 MPH, the sunroof suddenly fractured. The contact stated that there was no external cause to the failure. The vehicle was taken to the dealer. The vehicle was not diagnosed nor repaired. The contact decided to trade the vehicle. The manufacturer was not made aware of the failure. The approximate failure mileage was 13,300.

Mar 22, 2023

The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 21V00M000 (Visibility) however, the part to do the recall repair was unavailable. The dealer was made aware of the issue and confirmed that parts were not yet available. The manufacturer was made aware of the issue. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact had not experienced a failure. VIN tool confirms parts not available.

May 10, 2022

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.

Dec 28, 2021

POWER TRAIN,ENGINE

2 complaints

After initial startup and drive for a short time, I come to a stop. Then after vehicle doesn’t want to accelerate as it normally would. Vehicle struggles to gain speed but, the engine revs excessively. I pull off the road and come to a stop and try to accelerate again and the same thing happens. I shut the vehicle off and wait a few minutes,then restart and the vehicle accelerates normally again. There were no check engine lights the when this has happened.

Jul 27, 2025

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.

Nov 04, 2022

UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM

2 complaints

I bought this car in June 2013 for its safety and its Amazing warranty and all the features that it has Hyundai manufacture had an obligation as a consumer service and failed to send notification of any recalled to us in regards to a recall High pressure, fuel pump, and fuel rail Fuel system engine, gas tank This is a product of liability and negligence on time but they failed to take responsibility and comply with federal laws. I was driving with my family in the car when this car was a ticking Time bomb not even being aware of the Death trap on wheels. We ended having towed our home and then to then had to make a call next day and have it towed to Hyundai service center While we were driving this happen, where we heard two loud pops the gas gauge went down from 200 something to 80 engine lights came right up the backseats were heating up under my son seat in the back stated he felt waves as the backseat was getting hotter, we pulled over to a gas station and that’s when we had to call called O’Reillys and then we called a mechanic friend which stated that he ended up looking up the car and stated please pull over and get out car and called the Hyundai manufacture that there was a recall that’s the only way we found out other than that no prior incidents, then called the service technician of Hyundai i called amd complaint with the Honda manufacture corporate. They have failed to take the responsibility for this and they should be ashamed and take their accountability for this we could’ve died and anyone else around us on road as we drive this car daily The car was a higher risk of a ticking time bomb stated by the Hyundai service center technicians. this is an nere to miss accident narrowly avoid catastrophe

Jun 22, 2025

Injuries: 5

WAS PARKED IN BANK PARKING LOT. STARTED ENGINE, PLACED CAR IN REVERSE AND CAR ACCELERATED AT A VERY HIGH RATE OF SPEED. (LIKE I WAS IN A DRAG RACE!!) APPLIED BRAKES, WHICH DID NOT SLOW THE VEHICLE DOWN. DID NOT STOP UNTIL I RAN INTO A PARKED CAR. WHOLE INCIDENT TOOK JUST SECONDS. CAR HAD BEEN IN FOR REGULAR SERVICE AT THE DEALERS ON [XXX]. NOW HAS 16,597 MILES ON VEHICLE. CAR TO BE SERVICED AT RACHELS COLLISION, 720 S NOVA ROAD, DAYTONA BEACH, FL ON MONDAY [XXX]. IF I HAD NOT RAN INTO A PARKED CAR, I WOULD HAVE ENTERED [XXX] IN DAYTONA BEACH SHORES, FL WHICH WAS CROWDED WITH MOTORCYCLES.... FRIDAY NOON DURING BIKE WEEK. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Mar 10, 2024

Crash: 1

STRUCTURE

2 complaints

Sunroof exploded on the highway with no one in-front of me to kick up any rocks or debris.

Feb 10, 2025

I was driving down the highway with my mom, no cracks in any of my windows before any of this by the way. And my sunroof exploded. Huge huge explosion sound. I thought something fell but there was nothing above us.

Jun 11, 2023

SERVICE BRAKES,FORWARD COLLISION AVOIDANCE

2 complaints

Was driving in reverse out of garage and ABS brakes were applied like I hit a patch of ice stopping the car. Released when applied pressure to brake. Then while on highway going 60 miles an hour the emergency brake system went on for no reason applying pressure and red light came on the dash with a left facing arrow. System released within a few seconds but scared me and I still have to drive this car on highway.

Jan 29, 2025

Vehicle in front of me stopped. Six car lengths between us. I applied brakes, nothing, I even put my left foot on top of my right foot. There was plenty of time to stop but brake peddle wouldn’t go down, Felt like it was locked. Automatic Brake Sensor didn’t work either. Still waiting for inspection from manufacturer , 3 weeks. Never had any problems prior to this, After accident my warning came on about front collision failure .

May 05, 2023

Crash: 1

ENGINE,FUEL/PROPULSION SYSTEM

2 complaints

When attempting to pass other vehicles or under quick acceleration such as an on ramp to the highway, the vehicle will experience a sudden loss of power and oil pressure resulting in a fail safe mode which limits your acceleration and causes a sudden decrease in speed and velocity. The issue results in the oil pressure light illuminating and requires the vehicle to be stopped and completely turned off to reset then once turned back on, the problem is “gone” until a sudden acceleration occurs again, which results in the same issue happening. There is a current recall out for similar models but my vin is not listed. I have approximately 50k miles on the car, and am the first owner.

Jun 08, 2023

Oct 12: Engine stalled exiting I95 in Kittery Maine. Engine light flashed but did not stay on. Was able to get to safe place but car would not go more than 15mph. Hampton Huyndai reported mis-fire but stated it cleared on its own. Oct 17th: Engine stalled on highway ramp to I495, nearly causing me to be rear ended by other vehicles. Car would not go more than 15 mph. Engine light stayed on. Towed car to Key Salem Hyundai, defective injectors, warrantee repair. Oct 23rd: Car stalls on I93, was able to take immediate exit and turn engine off. Engine light flashed but did not stay on. Took car in to Salem dealership on Oct 24th, no code found. Oct 25th: Car stalls again on city street. Light stays on, Salem dealership replaces cat. convrtr between Oct 26th through Nov 4th. Nov 9th: Car stalls again on city street. Light stays on, currently in Salem dealership. This is a safety issue, in two cases already this car has nearly gotten me in an accident on the highway. I am seeking arbitration for replacement. I am scared to drive this vehicle. I will have a third invoice pending this next repair.

Nov 10, 2022

SEATS

1 complaint

The driver seat motor malfunctioned when pennies got jammed iin the unprotected/exposed seat tracks. Hyundai would not cover the warranty and charged me $2000.00 for repair. After complaining to the Hyundai National customer service they would not consider my point of contention that the unproteted/exposed tracks contributed to the failure. A professional mechanic stated that a fuse should have failed before the motor malfunctioned.

Nov 16, 2025

UNKNOWN OR OTHER,ENGINE,VISIBILITY/WIPER

1 complaint

The vehicle's HVAC (heating) system failed. It stopped producing heat on one side of the vehicle. My mechanic/dealer diagnosed the issue as a broken component within the HVAC case under the dashboard, requiring full dashboard removal and a repair estimated at over $3,000. This failure prevents the defroster from working properly, which is a major safety hazard as it cannot clear fog or frost from the windshield. A search of online forums and owner communities shows this is a widespread complaint from many other Hyundai owners, often identified as a failed blend door or blend door actuator, which requires the same expensive dashboard removal to repair.

Nov 08, 2025

POWER TRAIN,ELECTRICAL SYSTEM

1 complaint

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. A photo was provided to the mechanics of the dashboard showing the transmission service warning, with current mileage. The dealer advised there were no diagnostic log history showing the transmission error code even with photographic proof and attempted to return the vehicle to me. I have rejected the return of the vehicle and advised that this needs to be escalated, because if logs are not appearing, this is even a bigger cause for concern and that the vehicle is a safety hazard. Concern: Because this vehicle required an early transmission replacement and is now exhibiting new transmission/shifter warnings, I am concerned the failure relates to the known transmission/shifter recall on this model and that the recall scope and/or remedy is incomplete for the affected vehicles including my vin #. It is also possible the dealership is attempting to run out the warranty which expires in 3 months. Vehicle, photo of the warning, and service records are available for inspection. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Sep 05, 2025

AIR BAGS,FORWARD COLLISION AVOIDANCE

1 complaint

During a front end collision the car did not auto brake and the air bags did not deploy. The car has been totaled and is currently at a dealership for insurance appraisal.

Aug 08, 2025

Crash: 1

Injuries: 7

FUEL/PROPULSION SYSTEM

1 complaint

The car would excelerate while in park. While I was pressing the brakes the car would jerk forward, it would not just quietly idle. While driving the car would randomly speed up or slow down. Sometime it would sound like it was going to shut off and start vibrating.

Apr 23, 2025

FUEL SYSTEM, GASOLINE,ENGINE

1 complaint

The contact owns a 2021 Hyundai Sonata. The contact stated while pulling out of a parking lot, the vehicle failed to accelerate as intended and started shaking abnormally. The check engine warning light was illuminated. The vehicle was taken to the residence. The vehicle was towed to an independent mechanic where it was diagnosed that the fuel injector needed to be replaced. The vehicle was towed to a dealer where it was diagnosed that all four fuel injectors needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 47,000.

Mar 03, 2025

ENGINE,FORWARD COLLISION AVOIDANCE

1 complaint

The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the vehicle lost motive power. Additionally, the Forward Collision Avoidance failed to function as intended. The contact stated that the sensor was braking prematurely. The vehicle was taken to the dealer; however, the failure was not duplicated. The contact stated while driving out of the driveway, the vehicle lost motive power. The vehicle failed to restart. The dealer was contacted and made aware of the failure. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was unknown.

Sep 19, 2024

POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM

1 complaint

I have been to the dealership on three separate occasions due to the engine misfiring. Two ignition coils have been replaced so far and I recently returned to the dealership for the same issue. This time however, not only did the engine light come on but I went from a full tank to less than a quarter of a tank and the engine is making backfiring sounds. At that time the dealership said that they could not recreate the issue, I got my oil changed and went home. That was a week ago, I am back at the dealership today for the same thing; fuel dumping and backfiring sounds. While at the dealership today it turns out those backfiring noises were the fuel tank expanding so much so that it kept popping the seat up. They deemed the car unsafe to drive and it is currently at the dealership.

Jul 19, 2024

ENGINE AND ENGINE COOLING

1 complaint

The contact owns a 2021 Hyundai Sonata. The contact stated while driving 15 MPH, the contact noticed that the passenger’s side rear seat level had become elevated. The contact stated that his daughter who was seated in the child seat head had started touching the top of the sunroof. The contact became aware of a gasoline odor coming from the engine. The contact also became aware that the vehicle was consuming an abnormal amount of gasoline. There was no warning light illuminated. The vehicle was taken to the dealer however, the diagnostic test result was undisclosed. The dealer was unsure of how to service the vehicle. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 87,000. The VIN was not included.

May 23, 2024

POWER TRAIN,VEHICLE SPEED CONTROL

1 complaint

Vehicle began to lose power while on highway. The loss of power occurred for a few seconds, then came back. Shortly after, the RPM began changing uncontrollably. Tried shifting to manual control using paddle shifters and was able to maintain steady RPM until vehicle software switched back to automatic and RPM swung crazy again. Endangered other vehicles on road due to loss of power and fluctuations of transmission. Once parked, vehicle did not change to neutral, drive, reverse. Both manufacturer and insurance are/have reviewed vehicle and are working on a fix. No warning lights. Only indication was minor loss of power prior to incident. Loss of power was not considerable nor for a prolonged period of time.

Apr 25, 2024

SEAT BELTS

1 complaint

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, his son complained that the seat belt had tightened and locked and that he was unable to adjust the seat belt. Upon arriving at his destination, the contact stated that attempts to remove the seat belt had failed and the contact decided to cut the seat belt. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 26,450.

Aug 02, 2023

STEERING,ELECTRICAL SYSTEM

1 complaint

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.

Mar 14, 2023

FUEL/PROPULSION SYSTEM,VISIBILITY/WIPER,FORWARD COLLISION AVOIDANCE

1 complaint

My car barely has 11,000 miles and just the other day it had about 20miles left of gas but as I was driving on the road it started to feel and seem like it was about to die on me, Also the front Wipers are not well restrained with the vehicle you can tell by the way it moves when Wipers are on....Also most of the Signals be It if something is in front of me and the signal goes off BUT THERES NOTHING THERE ...ALSO WHEN IM BACKING UP SOMETIMES the car itself will Force stop as if something is in the way ...BUT AGAIN NOTHING IS THERE AT ALL ...IT HAPPENS EVERY FEW DAYS ....I JUST PURCHASED THIS CAR ..AND REALLY THINKING IT WAS WORST MISTAKE W ALL THESE ISSUES ALREADY

Feb 27, 2023

STRUCTURE,VISIBILITY

1 complaint

As I was driving down the road I heard what sounded like a gunshot and glass shattering. Upon getting to my destination I found that my panoramic sunroof had shattered outward.

Jan 25, 2023

STEERING,FORWARD COLLISION AVOIDANCE

1 complaint

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.

Dec 08, 2022

ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM

1 complaint

UNKNOWN

Oct 08, 2022

VEHICLE SPEED CONTROL,ENGINE

1 complaint

Since we purchased this brand new vehicle, we have had in the dealership service department at a minimum of 5 times for same issue. The vehicle accelerates while stopped at a light so we have to put it in neutral to keep it from accelerating. Once we take out of Neutral and release the break, the vehicle accelerates rapidly without stepping on the gas pedal. The computer system always comes on warning that we need to take to dealership because there are engine problems. Then it goes off and comes on again. We have contacted Hyundai to file a complaint and it has gone no where. We have taken it to Hyundai dealership in Tucson and they keep replacing parts per Hyundai manufacturer service tech reps. per same Egr codes. We are taking the vehicle to the dealership again today 9/22/22 because it started again around 9/1/22 and we have been waiting for a loaner car again from Dealership for same problems. Meawhile, being forced to drive it due to only owning 1vehicle. Hyundai Manufacturer has continued to have dealership change out parts and this keeps happening. The vehicle has just over 25K miles on it to date. The first time we had it in the dealership for this problem was on 4/6/22. We have almost rearended several vehicles and are scared to death to drive this vehicle. It is a safety hazard. We purchased the 2021 Sonata vehicle brand new on 11/24/21 along with the lifetime parts and labor warranty. It had 15 miles on it. We also traded our 2018 Hyundai ELantra. We paid off the 2021 Sonata completely in 2021. The total cost of this transaction was $34,294.74.We have also followed all the Maintenance requirements. It is urgent that this complaint is investigated as soon as possible and Hyundai Manufacturer take responsibility now before someone gets killed. The vehicle is obviously a dangerous manufactured vehicle.

Sep 22, 2022

FUEL SYSTEM, GASOLINE

1 complaint

The contact owns a 2021 Hyundai Sonata. The contact stated while driving at various speeds, he smelled an abnormally strong fuel odor inside the vehicle. There were no warning lights illuminated. The vehicle was taken to the dealer who informed the contact that they could duplicate the failure. The vehicle was then taken to a second dealer, Wayne Hyundai Parts and Service (1244 NJ-23, Wayne, NJ 07470) who could not duplicate the failure. The failure persisted. The contact stated that after driving the vehicle, his entire body had a strong fuel odor. The manufacturer was notified of the failure and referred the contact to another dealer. The vehicle was not diagnosed or repaired. The failure mileage was approximately 21,000.

Sep 14, 2022

AIR BAGS,FORWARD COLLISION AVOIDANCE,LANE DEPARTURE

1 complaint

Unknown

Jul 15, 2022

AIR BAGS

1 complaint

I turned on a highway and had gotten my car up to 45 mph when a deer came out of nowhere and I slammed into it hard back on January 12th. The car only suffered cosmetic damage thankfully, but the air bags did not deploy. I have since then found out that the front air bag crash sensors are in a spot where they are practically useless unless you hit something pretty high up and destroy the headlights in the process. In my opinion, this is a serious safety issue, and when I contacted Hyundai about it, all they told me was to go to the dealership for inspection. I have pictures showing that the crash sensors are located at and not where they should be, and if you open the hood, the wiring for the sensors is right in your face. I still have high anxiety knowing that if I get into another accident, they may not deploy due to their location. At least the car is still drivable and no structural damage or alignment issues are there. As you can see in the pictures the sensors are close to where the hood closes at the top support bar.

Mar 11, 2022

Crash: 1

AIR BAGS,SEATS

1 complaint

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.

Oct 07, 2021

PARKING BRAKE,UNKNOWN OR OTHER

1 complaint

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.

Jul 22, 2021

Crash: 1

2021 HYUNDAI Sonata Problems & Complaints

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