FaultScore

FaultScore report

2021 Hyundai Sonata problems

Owners have filed 180 complaints about the 2021 Hyundai Sonata with NHTSA between 2021 and 2026. The largest single group is the engine & cooling. Across this model's run it ranks 24 of 32 worst.

B

FaultScore 37/100

Higher is worse. Measured against the other years of the Hyundai Sonata.

How this is worked out

The numbers

180

Complaints

11

Crashes reported

0

Fires reported

4

Injuries reported

35,000 mi

Median mileage at failure

Half of reported failures happened before this

52%

Failed under 36,000 miles

Inside a typical bumper-to-bumper warranty

What kind of bad

The letter says how bad. This says what kind — whether this year drew an unusual number of complaints, unusually dangerous ones, or failures that arrived unusually early.

Complaint volume 13 vs 50 Severity 43 vs 50 Early failure 88 vs 50
The dashed ring is 50 — the national norm. Further out is worse.
Complaint volume — 13
Against the median year of the Hyundai Sonata. 50 means typical for this model; 100 means roughly double.
Severity — 43
8.3% of these complaints involved a crash, fire, injury or death, against a national rate of 9.7%.
Early failure — 88
52% of failures with a mileage on record happened under 36,000 miles, against a national rate of 29%.

How 2021 compares with every other Hyundai Sonata

Click any bar to open that year's report.

Complaints filed with NHTSA, by model year. Bar colour is the FaultScore grade: A B C D F ungraded

What breaks on a 2021 Hyundai Sonata

Every complaint is filed against a part. Follow any row for the complaints about that part alone.

Engine & Cooling 35 19.4%

1 crashes, 0 fires · median 45,500 mi

3 crashes, 0 fires · median 1,400 mi

1 crashes, 0 fires · median 75,242 mi

Median failure at 21,500 miles

Median failure at 13,300 miles

2 crashes, 0 fires

Body & Structure 4 2.2%
Brakes 4 2.2%

2 crashes, 0 fires · median 21,700 mi

Airbags 4 2.2%

2 crashes, 0 fires

Seats 2 1.1%
Seat Belts 2 1.1%

Median failure at 26,450 miles

Acceleration & Cruise Control 2 1.1%
Steering 2 1.1%
Suspension 1 0.6%

When it fails

Odometer readings owners gave when they filed. About half of all complaints include one.

1,000 – 9,999 miles 6 22.2%
10,000 – 24,999 miles 5 18.5%
25,000 – 49,999 miles 8 29.6%
50,000 – 74,999 miles 2 7.4%
75,000 – 99,999 miles 3 11.1%
100,000 – 149,999 miles 3 11.1%

When owners complained

A spike years after the car went on sale usually means a part wearing out on schedule across the whole fleet — the kind of pattern no single owner can see from inside their own car.

Mar 2021 peak 12 Aug 2026

NHTSA investigations into the 2021 Hyundai Sonata

An investigation is the step before a recall: the agency has seen enough complaints to look into a pattern itself. An open one means it thinks something may be wrong and nothing has been fixed yet.

DP22003 Opened 12 Sep 2022 Closed 12 Dec 2023 ENGINE

Loss of Motive Power

The National Highway Traffic Safety Administration (NHTSA) received a letter dated July 13, 2022, petitioning the Agency to initiate a safety defect investigation into loss of motive power allegations attributed to oil drain pan assembly failures on certain Hyundai Motor America, Inc. and Kia America, Inc. vehicles spanning Model Years (MY) 2005-2021. The Petitioners cited examples of complaints indicating that the subject vehicles were experiencing rapid loss of engine oil due to oil drain plug back outs, resulting in loss of motive power and/or catastrophic engine damage. Additional complain...

Recalls on the 2021 Hyundai Sonata

A complaint is one owner's allegation. A recall is the point at which the manufacturer or a regulator agreed the defect is real and dangerous enough to fix for free — however old the car is.

United States — NHTSA

25V796000

FUEL SYSTEM, GASOLINE

Hyundai Motor America (Hyundai) is recalling certain 2020-2023 Sonata vehicles. A damaged check valve can allow air to enter the fuel tank, causing it to expand and contact hot exhaust components, melting the tank.

Risk: A melted fuel tank can leak, increasing the risk of a fire.

22V746000

POWER TRAIN:AUTOMATIC TRANSMISSION

Hyundai Motor Company (Hyundai) is recalling certain 2021-2022 Santa Fe, Sonata, Veloster N, 2022 Santa Cruz, Elantra N, and Kona N vehicles. The vehicle's "fail-safe" limited-mobility drive mode may be impaired, when prompted by a transmission oil pump malfunction, which can result in a complete loss of drive power.

Risk: Loss of drive power increases the risk of a crash.

21V00M000

VISIBILITY:WINDSHIELD

Hyundai Motor America (Hyundai) is recalling certain 2020-2021 Santa Fe, 2021 Sonata, and Elantra vehicles. During manufacturing, the windshield may not have been properly bonded to the vehicle, allowing it to detach in a crash.

Risk: A windshield that detaches from a vehicle during a crash can increase the risk of injury.

21V524000

FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS

Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Santa Fe and Sonata vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.

Risk: A fuel leak increases the risk of a fire.

Canada — Transport Canada

Canada runs its own recall programme, and its campaigns do not always mirror the American ones.

Recall 2025637 5,616 units in Canada

Fuel System

Issue: On certain vehicles, the check valve for the purge control system could wear and cause the fuel tank to expand. As a result, the fuel tank could contact hot components and fuel could leak. Note: This recall only affects certain vehicles equipped with a 1.6 L turbocharged engine. This safety recall replaces emissions recall no. ECR-H0003-24-005 (Hyundai recall no. C0566). Vehicles that were repaired under that recall also require this repair. Safety Risk: A fuel leak can create the risk of a fire. Corrective Actions: Hyundai will notify owners by mail and advise you to take your vehicle to a dealership to inspect and, if necessary, replace the check valve and update the electronic control unit (ECU) software. The dealer will also inspect the fuel tank and surrounding components and repair them, as necessary.

Recall 2022568 9,427 units in Canada

Powertrain

Issue: On certain vehicles, a fault in the transmission oil pump can cause the vehicle to enter "fail-safe mode". When this happens, a programming error can cause a sudden loss of power to the wheels after 20-30 seconds. Note: This recall only affects certain vehicles equipped with an 8-speed dual-clutch transmission (DCT). Safety Risk: A sudden loss of power to the wheels could increase the risk of a crash. Corrective Actions: Hyundai will notify owners by mail and instruct you to take your vehicle to a dealership to inspect and, if necessary, replace the transmission. The dealer will also update the transmission control unit software.

Recall 2021791 1,893 units in Canada

Structure

Issue: On certain vehicles, the windshield may not be properly attached. As a result, the glass can become loose and could separate from the vehicle in a crash. Safety Risk: A windshield that detaches in a crash could create an increased risk of injury. Corrective Action: Hyundai will notify owners by mail and instruct you to take your vehicle to a dealer to remove and reinstall the windshield.

Recall 2021426 2,285 units in Canada

Fuel System

Issue: On certain vehicles, the connection between the high-pressure fuel pipe and fuel pump may not be properly sealed. As a result, a fuel leak could occur. Safety Risk: A fuel leak can create the risk of a fire. Corrective Action: Hyundai will notify owners by mail and instruct you to bring your vehicle to a dealer to inspect and replace the high-pressure fuel pipe, as required.

Recalls cover specific build ranges, so check your own vehicle by VIN at nhtsa.gov/recalls or, in Canada, Transport Canada.

Complaints that involved harm

Reports where the owner recorded a crash, a fire, an injury or a death.

Woodway, TX Crash 7 injured

AIR BAGS

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.

NHTSA complaint #11679381 — an unverified report by a vehicle owner.

Woodway, TX Crash 7 injured

FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING

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.

NHTSA complaint #11679381 — an unverified report by a vehicle owner.

Sacramento, CA 5 injured

UNKNOWN OR OTHER

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

NHTSA complaint #11668446 — an unverified report by a vehicle owner.

Sacramento, CA 5 injured

FUEL/PROPULSION SYSTEM

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

NHTSA complaint #11668446 — an unverified report by a vehicle owner.

Vancouver, WA Crash

ENGINE

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)

NHTSA complaint #11615509 — an unverified report by a vehicle owner.

Ponce Inlet, FL Crash

UNKNOWN OR OTHER

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)

NHTSA complaint #11576439 — an unverified report by a vehicle owner.

The most recent complaints

In the owners' own words, exactly as filed with NHTSA.

Rosedale, MD

FUEL/PROPULSION SYSTEM

I took my vehicle in for the safety recall due to an expanding fuel tank on 08/03/2026. I received my vehicle back on 8/12/2026. Hyundai performed an improper repair on the vehicle that will not correct the fuel tank expansion. They replaced the same check valve that was replaced last time I brought the vehicle in for recall on 11/20/2024 repair order # 107221 at Jones Hyundai of Belair. This valve did not and will not correct the fuel tank expansion issue. The expansion issue is caused by fuel getting past the check valve and entering the purge control system. The correct repair is to replace the fuel tank and the purge control system, as the check valve has already allowed fuel to bypass it and enter the system causing the expansion issue. . Replacing the valve that failed & allowed fuel into the system & caused the tank to expand will not correct the issue caused by the failed valve. My fuel tank has not decompressed. I still have the same problem I brought the vehicle in for because the repair Hyundai advised NHTSA on was NOT performed.

NHTSA complaint #11757244 — an unverified report by a vehicle owner.

Columbus, OH

ELECTRICAL SYSTEM

The Left blinker switch keeps going in and out, working about 50% of the time. Both the light and the blinker sound do not turn on. When getting it checked out at an auto repair shop, the maintenance tech said this was more and more common for 2021 sonatas and it was not due to anything I did. It was a multifunction switch problem.

NHTSA complaint #11755451 — an unverified report by a vehicle owner.

Dallas, TX

FUEL/PROPULSION SYSTEM

Gas tank expansion and pcv melted. Car smells like gas when I was driving earlier, and my garage was flooded with the fumes of gasoline.

NHTSA complaint #11755570 — an unverified report by a vehicle owner.

at 50,200 miles Jamaica, NY

FUEL SYSTEM, GASOLINE

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the fuel gauge indicated that the tank was half full. The contact stated that the gauge erroneously indicated that the tank was empty, and the check engine warning light was illuminated. The vehicle was driven to the gas station, and while attempting to refuel the vehicle, the fuel did not go into the tank. The vehicle was towed to the residence. The vehicle was later towed to the dealer, where it was diagnosed with a failed fuel system and a failed fuel tank. The contact was informed that the fuel system and fuel tank needed to be replaced. The vehicle was not repaired. The contact was informed that the failure was associated with the unrepaired recall. The contact was informed that the vehicle was a fire risk. In addition, the contact was informed that there was a hole in the fuel tank that caused the fuel to leak out of the fuel tank. The contact was informed that the parts were ordered to repair the vehicle. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline). The manufacturer was not made aware of the failure. The failure mileage was approximately 50,200.

NHTSA complaint #11754791 — an unverified report by a vehicle owner.

Lake Charles, LA

POWER TRAIN

Going down the road driving the car lost power and went in limp mode with no warnings on the dash at all!

NHTSA complaint #11754136 — an unverified report by a vehicle owner.

Lake Charles, LA

ENGINE

Going down the road driving the car lost power and went in limp mode with no warnings on the dash at all!

NHTSA complaint #11754136 — an unverified report by a vehicle owner.

Kaysville, UT

UNKNOWN OR OTHER

1. Component Failed: Panoramic Sunroof Glass Assembly (Structure / Visibility / Glass). Details: While traveling at highway speed on the freeway, the panoramic sunroof glass spontaneously exploded outward without warning or impact from any foreign object. Inspection: I have not had the vehicle repaired yet so it is currently available. I also took a picture of it. 2. Safety Risk: The sudden, loud explosion (sounding like a gunshot) at freeway speeds caused immediate driver distraction and severe disorientation. Shattered tempered glass was mostly restricted from the cabin by the curtain barrier but some rained down into the passenger cabin. Most blew backward onto the highway, posing a major hazard to occupants as well as trailing motorists. Furthermore, this is a recurring defect in our household: my wife experienced an identical spontaneous sunroof explosion on her 2024 Hyundai Palisade, demonstrating a pattern of hazardous glass failures across multiple late-model Hyundai vehicles. 3. Reproduced or confirmed: I have not had it inspected by anyone. I am awaiting quotes for repairs. I have taken a picture of the vehicle that has not been driven since the incident. 4. Inspection: No one else has inspected it. I have a picture and can take more as needed. Hoping to not have to drive it until I take it to a shop for repairs. It has been reported to a dealership, but they did not seem too concerned or interested in helping. They insisted that they would not give a repair quote until I drove it the 20 miles for them to inspect. 5. Any Warning: No warning. There were no warning lights, abnormal noises, visible cracks, or previous symptoms prior to the sudden explosion. The failure occurred completely spontaneously under normal highway driving conditions.

NHTSA complaint #11753241 — an unverified report by a vehicle owner.

at 80,484 miles Rosedale, MD

FUEL SYSTEM, GASOLINE

The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (FUEL SYSTEM, GASOLINE); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The vehicle was taken to the local dealer, and the contact was informed that the fuel tank was swollen and needed to be replaced. The vehicle was not yet repaired. The failure mileage was 80,484.

NHTSA complaint #11753027 — an unverified report by a vehicle owner.

Plainfield, IL

FUEL/PROPULSION SYSTEM

Engine revving at a complete stop. Surging engine while braking. I was forced to put into neutral when stopping. I had check engine prior that read P049D85. It went away. The Hyundai dealer said to be the EGR valve. Nick Hayes at D'Arcy Hyundai and Hyundai Motor America (HMA) agreeing to a 75% goodwill split of cost to repair.

NHTSA complaint #11753130 — an unverified report by a vehicle owner.

Centreville, VA

UNKNOWN OR OTHER

The panoramic sunroof spontaneously exploded while driving without any external impact

NHTSA complaint #11752333 — an unverified report by a vehicle owner.

at 42,000 miles Boynton Beach, FL

SERVICE BRAKES

The contact owns a 2021 Hyundai Sonata. The contact stated that while driving 10 MPH and attempting to make a right turn, the brakes independently activated. Neither the dealer nor an independent mechanic was contacted. The check engine warning light was illuminated. The contact stated that the failure had occurred on several occasions. The vehicle was taken to the dealer and an independent mechanic to be diagnosed. The manufacturer was not notified of the failure. The approximate failure mileage was 42,000.

NHTSA complaint #11747445 — an unverified report by a vehicle owner.

Lexington, SC

ENGINE

At approximately 130,000 miles, vehicle developed and internal coolant leak caused by a failed Exhaust Heat Recovery System (EHRS) in the center muffler assembly, matching TSB 23-EM-009H - a known manufacturing defect documented by Hyundai. Coolant has been slowly leaking internally into the exhaust system. The authorized Hyundai dealership initially failed to diagnose the internal leak and told me there was no leak and wanted to send me home. After pushing back, the internal leak was confirmed. If not caught, this defect could result in engine overheating or complete engine failure without warning. Hyundai Motor America has denied goodwill coverage despite this being a documented manufacturing defect.

NHTSA complaint #11746137 — an unverified report by a vehicle owner.

Lexington, SC

FUEL/PROPULSION SYSTEM

At approximately 130,000 miles, vehicle developed and internal coolant leak caused by a failed Exhaust Heat Recovery System (EHRS) in the center muffler assembly, matching TSB 23-EM-009H - a known manufacturing defect documented by Hyundai. Coolant has been slowly leaking internally into the exhaust system. The authorized Hyundai dealership initially failed to diagnose the internal leak and told me there was no leak and wanted to send me home. After pushing back, the internal leak was confirmed. If not caught, this defect could result in engine overheating or complete engine failure without warning. Hyundai Motor America has denied goodwill coverage despite this being a documented manufacturing defect.

NHTSA complaint #11746137 — an unverified report by a vehicle owner.

Cumming, GA

POWER TRAIN

The vehicle has experienced repeated transmission and Electronic Oil Pump (EOP) failures resulting in loss of propulsion, loss of acceleration, and transmission-related malfunctions. The vehicle currently has approximately 69,000 miles. On September 3, 2022, the vehicle lost propulsion while traveling approximately 31 MPH in traffic and would not respond normally to accelerator input. This created a dangerous situation and increased the risk of a collision. On the same date, while backing out of a parking space, the vehicle displayed a "Shifter System Malfunction" warning message and unexpectedly stopped while in reverse. The vehicle had to be powered off before it would operate again. Following these incidents, the vehicle was towed to a Hyundai dealership and the transmission was replaced in September 2022. Despite the transmission replacement, the vehicle continued experiencing issues involving the same system. The Electronic Oil Pump (EOP) was replaced in 2023 and again in 2024 due to recurring transmission-related concerns and diagnostic codes. In 2026, the check engine light returned and the vehicle was again diagnosed with a transmission-related failure. The dealership determined that the transmission requires replacement for a second time despite the previous transmission replacement and two separate EOP replacements. Internally, Hyundai has since revised its repair guidance for this condition, suggesting that prior repair procedures may not have fully addressed the underlying defect. The repeated failures of the transmission and EOP system despite multiple repairs suggest an underlying defect that has not been corrected. These failures create a significant safety risk because the vehicle can unexpectedly lose propulsion or fail to accelerate while operating in traffic. The vehicle is available for inspection upon request.

NHTSA complaint #11741226 — an unverified report by a vehicle owner.

Clarksville, TN

ELECTRICAL SYSTEM

The car will idle high around 1200 rpms. The car will most of the times fix the issue when you turn the car off and back on but it will start again after driving. This is a known issue with the car. I have had the egr valve replaced since it will pop up the codes P240F and P049 for egr slow response and control position exceeded learning limit but the problem came back within two days. I did find a forum that deals with the joint connector repair but this needs to be a recall as I have come across many people who have this problem and paying out of pocket to fix it.

NHTSA complaint #11741201 — an unverified report by a vehicle owner.

Clarksville, TN

ENGINE

The car will idle high around 1200 rpms. The car will most of the times fix the issue when you turn the car off and back on but it will start again after driving. This is a known issue with the car. I have had the egr valve replaced since it will pop up the codes P240F and P049 for egr slow response and control position exceeded learning limit but the problem came back within two days. I did find a forum that deals with the joint connector repair but this needs to be a recall as I have come across many people who have this problem and paying out of pocket to fix it.

NHTSA complaint #11741201 — an unverified report by a vehicle owner.

Lynchburg, VA

FUEL/PROPULSION SYSTEM

I took my car to dealer to repair recall. Dealer told me if it failed they would keep car and report stolen if I tried to take it. They failed it. I didn't trust them based on their report it stolen statement. I had the police get my car back. I took it to another dealer where it passed recall easily. I believe they wanted my car for a customer, and tried to get away with this ruse.

NHTSA complaint #11739443 — an unverified report by a vehicle owner.

at 140,000 miles Daytona Beach, FL

FUEL SYSTEM, GASOLINE

The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the engine shuddered and the engine stalled. In addition, the engine seized. No warning lights were illuminated. The contact stated that the vehicle was seized in the middle of the road. The contact stated that while attempting to start the vehicle, the vehicle started. The failure reoccurred. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 140,000.

NHTSA complaint #11738864 — an unverified report by a vehicle owner.

at 140,000 miles Daytona Beach, FL

ENGINE

The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the engine shuddered and the engine stalled. In addition, the engine seized. No warning lights were illuminated. The contact stated that the vehicle was seized in the middle of the road. The contact stated that while attempting to start the vehicle, the vehicle started. The failure reoccurred. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 140,000.

NHTSA complaint #11738864 — an unverified report by a vehicle owner.

Dothan, AL

ENGINE

The Exhaust Heat Recovery System (EHRS) has failed for the second time on this vehicle. The first failure occurred at approximately 35,000 miles and was repaired under Hyundai Technical Service Bulletin 23-EM-009H, which Hyundai issued to address this exact defect across 2020-2023 Sonata Hybrid models. The vehicle has now reached 71,000 miles and is experiencing the identical symptoms: coolant loss, overheating, and white exhaust smoke. The EHRS shares a coolant loop with the hybrid battery thermal management system. Coolant loss from this failure puts the hybrid battery and power electronics at risk of overheating, creating a potential fire and safety hazard. The recurring nature of this failure following an official TSB repair suggests the root cause has not been adequately addressed by Hyundai's current repair protocol.

NHTSA complaint #11730992 — an unverified report by a vehicle owner.

Baton Rouge, LA

UNKNOWN OR OTHER

• I experienced trouble with my splash guard being damaged from hanging and scraping the ground about a month after purchasing the vehicle. Also, my hood paint started chipping after a recent cold front experienced in my state earlier this year. Yes it is available for inspection upon request. Regarding the splash guard, not applicable. • It’s was very inconvenient to drive with a portion of my car scraping the ground. I had to be more mindful of my driving in the higher speed limit areas incase the splash guard detached. I had it re-attached multiple times. Regarding the chipped paint, not applicable. • It it counts, for my splash guard, during a servicing, I asked Hyundai to re-attach it. For the chipped paint, no. • The splash guard has during a past servicing. The chipped paint is more recent so it hasn’t • No. Splash guard, a month after purchasing vehicle. The chipped paint, earlier this year, January-February 2026.

NHTSA complaint #11730039 — an unverified report by a vehicle owner.

Baton Rouge, LA

STRUCTURE:BODY

• I experienced trouble with my splash guard being damaged from hanging and scraping the ground about a month after purchasing the vehicle. Also, my hood paint started chipping after a recent cold front experienced in my state earlier this year. Yes it is available for inspection upon request. Regarding the splash guard, not applicable. • It’s was very inconvenient to drive with a portion of my car scraping the ground. I had to be more mindful of my driving in the higher speed limit areas incase the splash guard detached. I had it re-attached multiple times. Regarding the chipped paint, not applicable. • It it counts, for my splash guard, during a servicing, I asked Hyundai to re-attach it. For the chipped paint, no. • The splash guard has during a past servicing. The chipped paint is more recent so it hasn’t • No. Splash guard, a month after purchasing vehicle. The chipped paint, earlier this year, January-February 2026.

NHTSA complaint #11730039 — an unverified report by a vehicle owner.

Troy, MO

UNKNOWN OR OTHER

I was notified of a recall on my from vehicle by Hyundai via email some time in March of 2026. The message said mentioned my vehicle may have a defective/worn purge control check valve that would cause the fuel tank to deform. Potentially leading to a release of fuel over time, which then could ignite. NHTSA Recall #25V796000 My car showed now signs of problems, but I brought it into a Hyundai dealership on March 13th where they confirmed my vehicle had the issue. They said the situation required I not drive my vehicle and gave me a rental in the meantime. I assumed it would be a simple swap of the fuel tank and everything would be fine. I was offered a buyback from my Hyundai claims manager over the situation, but I figured since its a simple fix, I'd keep my car and have it fixed. Two weeks went by with no update from the dealership, so I walked in for answers. Turns out, the subframe of my car has been damaged by the expanding fuel tank and they are still waiting for updates from Hyundai on how to proceed as they themselves don't know how to fix my vehicle. My Hyundai claims manager did not mention this when we talked over the phone and he offered a buyback. None of their recall notices mention structural damage anywhere or even as a possibility. I asked the dealership again on April 1, 2026, and they are still waiting on guidance on how to proceed. Neither does my Hyundai claims manager handling this situation on their end.

NHTSA complaint #11729119 — an unverified report by a vehicle owner.

Troy, MO

FUEL/PROPULSION SYSTEM

I was notified of a recall on my from vehicle by Hyundai via email some time in March of 2026. The message said mentioned my vehicle may have a defective/worn purge control check valve that would cause the fuel tank to deform. Potentially leading to a release of fuel over time, which then could ignite. NHTSA Recall #25V796000 My car showed now signs of problems, but I brought it into a Hyundai dealership on March 13th where they confirmed my vehicle had the issue. They said the situation required I not drive my vehicle and gave me a rental in the meantime. I assumed it would be a simple swap of the fuel tank and everything would be fine. I was offered a buyback from my Hyundai claims manager over the situation, but I figured since its a simple fix, I'd keep my car and have it fixed. Two weeks went by with no update from the dealership, so I walked in for answers. Turns out, the subframe of my car has been damaged by the expanding fuel tank and they are still waiting for updates from Hyundai on how to proceed as they themselves don't know how to fix my vehicle. My Hyundai claims manager did not mention this when we talked over the phone and he offered a buyback. None of their recall notices mention structural damage anywhere or even as a possibility. I asked the dealership again on April 1, 2026, and they are still waiting on guidance on how to proceed. Neither does my Hyundai claims manager handling this situation on their end.

NHTSA complaint #11729119 — an unverified report by a vehicle owner.

Brownsville, PA

ENGINE

The internal core of the Exhaust Heat Recovery System (EHRS), part of the center muffler/front pipe assembly (#28600-L5210), suffered a catastrophic failure. This allowed approximately 9 gallons of engine coolant to leak directly into the hot exhaust stream. Safety Risk: This failure creates a severe visibility hazard. During acceleration from stop lights and stop signs, the vehicle emits massive, thick clouds of white glycol smoke. The smoke is so dense that it completely obscures the driver's view of trailing vehicles and prevents following drivers from seeing the roadway or my vehicle's brake lights, creating a high risk of rear-end collisions. Additionally, the rapid loss of coolant caused the engine to overheat and lose power while in motion, nearly causing a stall in active traffic. Confirmation: The failure was confirmed by the service department at Washington Hyundai (Invoice #174281). This is the second failure of this specific component (previously failed in Jan 2025). The manufacturer issued TSB 23-EM-009H for this defect, acknowledging it affects 2020-2023 Sonata Hybrids, but no safety recall has been issued. Symptoms: The issue was preceded by a "sweet" burning smell and a sudden "Engine Overheating" warning on the dashboard. The failed component has been replaced by the dealer, but the manufacturer refused to replace the coolant-poisoned Oxygen (O2) sensors, leaving the vehicle in a technically compromised state. The failed unit is likely held by the dealer for warranty parts return.

NHTSA complaint #11727380 — an unverified report by a vehicle owner.