What 75 owners told NHTSA about the 2021 Hyundai Tucson Fuel Cell

We were driving and the engine light started flashing and buckling. The vehicle had been properly maintained with oil changes. We have oil changes receipts from our mechanic. Hyundai refuses to cover it under their warranty even though there are documented issues with the make and models of 2021 Hyundai Tuscons.

NHTSA ODI 11699481

Engine started making a knocking sound, then the oil light came on followed by the check engine light. Accelerates and decelerates on its own. Was forced to immediately pull over across three lanes on Interstate 95. It’s been over two weeks and I’ve yet to hear if Hyundai is going to cover a replacement engine. However, what happened is exactly what they have listed on their website ️ What to look out for check-engine Check Engine oil-light Engine Oil Pressure A knocking noise from the engine that increases in frequency as the engine rpm increases. Reduced power and/or hesitation and vibration. Illumination of the “check engine” light in the instrument cluster. Illumination of the “engine oil pressure” warning lamp.

NHTSA ODI 11697532

My family’s safety is at serious risk with my 2021 Hyundai Tucson, which I’ve owned only 55 days. This vehicle has stalled three times while driving, putting me and my two young children in immediate danger. Each time, the car operated normally until a flashing engine light appeared, RPMs spiked, and the vehicle suddenly lost all power—entering “limp mode” and unable to exceed 3,000 RPM or 50 MPH. The first failure occurred 9/14/25 while merging onto the interstate, forcing me to lose power mid-acceleration as surrounding vehicles slammed their brakes to avoid collision. 13 days later, it happened again in stop-and-go traffic, leaving me stranded on the shoulder. Both incidents occurred without warning or prior check-engine lights. The third—and most terrifying—incident was on October 17, 2025, when the engine completely died 300 miles from home on a busy highway. My children, ages 4 and 6, were terrified as cars sped by. We were extremely fortunate not to have been hit. I am urgently requesting assistance for the immediate replacement of this vehicle’s engine. It is covered by Hyundai’s 15-year/150,000-mile extended warranty, clear evidence the company was aware of these issues. Service records from the previous owner-that I was told about by Hyundai show ongoing engine problems and recalls since 2022 further proof this vehicle should have been retired from service As a parent, I’m very alarmed that Hyundai refuses to act until “catastrophic damage” occurs. This policy is irresponsible and endangers entire families. There’s at least 50 NHTSA complaints describing identical issues; stalling, power loss, and bearing failure linked to defective connecting rod bearings. Yet, Hyundai has denied a replacement, insisting on waiting for further damage and failures in operation. I beg you to intervene and prioritize my family’s safety before tragedy inevitably strikes. My children should not be put at risk due to corporate negligence, greed and absence of accountability.

NHTSA ODI 11697088

Engine started making a knocking sound, light came on. Accelerates and decelerates on it's own. Dealership will not provide a diagnosis in any way, but says complete engine replacement is the answer. Car has been at dealership for almost a month.

NHTSA ODI 11694086

I was trying to defrost my windows and my air was on so I clicked the air off so the heat could come on and I started smelling a matalicky smell. I drove to a stop light and when I stopped the back windshield popped and then shattered. I then went to drive again to take the car home and I started to see smoke. Once the light changed I continued to drive to get the car home I happened to look through the rear view mirror and saw fire in the trunk , once I saw the fire I pulled over on a street and stopped the car and then all the sirens in the car started going off so I turned the car off got out and called 911.

NHTSA ODI 11691247

While driving on a major highway, my car went into limp mode topping out at 60 mph then decreasing before going back to 60. My check engine light was also blinking, not solid.

NHTSA ODI 11687118

While driving on the freeway my sunroof suddenly imploded sending glass everywhere. No warning whatsoever it was like a bomb went off out of nowhere. Nothing hit the car and temps were not high and it just imploded This is a serious matter and extremely dangerous. The pain and ringing in my ears is awful, glass went all over this is serious issue that can cause death and injury

NHTSA ODI 11681195

When going through Auburn, AL with speed limit of 70 mph my car engine started blinking on and off then my car dropped down only allowing me to go 60 Mph.

NHTSA ODI 11677461

On [XXX], the vehicle was involved in a complex multi-impact accident. It was struck by a vehicle on the passenger (right) side and, simultaneously, by another vehicle on the driver's (left) side. (Police Report). During this sequence of collisions, and despite the magnitude of the impact, I must express my extreme concern that the left side airbag (driver's side) did not deploy. This failure caused Mr. [XXX] , the undersigned, to suffer a neck injury as a direct consequence of the incident. Even more seriously, the right-side passenger, Ms. [XXX] , sufferedsevere internal injuries, including three small intestine perforations, according to medical reports. These injuries resulted from improper pressure or malfunction of the seatbelt for that seat. These combined failures, the non-deployment of an essential airbag in impact, and the serious internal injuries caused by the seatbelt represent unacceptable deficiencies in the vehicle's safety systems. We believe that these injuries could have been avoided or mitigated if the safety components had functioned properly, as expected in an accident situation of this magnitude. Therefore, I am at a loss to understand: 1. Why the left side airbag did not deploy during the impact. 2. Why the right passenger seatbelt caused such serious internal injuries, including the three diagnosed intestinal perforations. We also require that concrete and immediate action be taken to address and compensate for the serious injuries suffered by the vehicle's occupants, as this has caused psychological and work- related harm. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11675342

There was a recall on this engine which I had updated the knock sensor campaign. While on the highway the engine light started flashing and the speed was reduced to 20 mph on a major highway. I had to almost cause a wreck to get off highway. The vehicle went into limp mode with no prior indication

NHTSA ODI 11673649

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving 35-45 MPH, the vehicle shut off unexpectedly. There was an abnormal rattling sound coming from the vehicle. Additionally, the contact stated that the vehicle failed to accelerate while driving. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed that the rod bearing and the engine needed to be replaced. The vehicle was repaired; however, the failure recurred. The vehicle was taken to another local dealer, Hyundai of Orange Park (7600 Blanding Blvd, Jacksonville, FL 32244); who determined that the coils needed to be replaced. The vehicle was not repaired. The vehicle was taken to an independent mechanic who replaced the coils and determined the failure was due to the engine. The vehicle was repaired, but the failure reoccurred. The manufacturer was contacted, but no additional assistance was provided. The failure mileage was approximately 124,500.

NHTSA ODI 11661259

When sitting at a stop and then accelerating to leave the stop position, the car will go and then all of a sudden it will stall out and I'm pressing the gas pedal, pressing the gas pedal quite a few times before the car even decides to move. This happens when I'm changing lanes on the highway... merging onto the highway... when I'm leaving from a stop sign or a stoplight it happens continuously. It is very dangerous and it can cause a very bad accident....this has been an issue since I had bought the car 3 years ago...it seems to be happening more frequent

NHTSA ODI 11660001

The AC system on my vehicle stopped working with less than 55,000 miles on it. When replacing the compressor, condenser, all AC switches, and lines (the entire AC system besides the ECM), the AC is still not working. The compressor is not kicking on. I have an ECM on order, but myself, and all mechanics (including Hyundai certified mechanics) are all unsure why this would have happened on such a low mileage vehicle. I am EXTREMELY disappointed and frustrated with the experience and not having AC after spending thousands of dollars and time getting it fixed. Please advise ASAP. Attached is the original invoice stating that all that needed to be replaced was the condenser/compressor. I have more files from all of the other replacements provided if needed.

NHTSA ODI 11656391

Vehicle has 36,300 miles. Engine stalled twice when shifting into reverse, MID displayed "BCW On, Check System." Continued driving home, vehicle experiences power loss (rpms drop to ~500) and electrical system sputters and sparking noises can be heard in the cabin momentarily when turning left or steering left for curves at speeds over ~20mph. Checked BCW sensor location in rear bumper for obstructions - vehicle is clean.

NHTSA ODI 11644245

Around November 1, 2024 my 2021 Tucson check engine light came on. I had this checked out and was told by a mechanic that it was the Camshaft Sensor. I had this repaired and then on November 23rd while traveling to Ohio my Check Engine light started flashing and needed immediate attention. I was on the West Virginia Turnpike when this happened and it caused the car to go no more that 45 mph in a zone marked 65mph. We got this immediately checked out and repaired and then 4 days later the same thing happened while in Ohio. It was taken to Deihl Hyundai in Massillon, Ohio and they once again made this repair with video evidence of said repairs. Once again while driving at freeway speed on December 23rd my car experienced this malfunction. The same dealership fixed it once again with direction from Hyundai. I am concerned for this is an ongoing problem and could cause serious injury to myself or others in my vehicle if this would happen once again on a freeway.

NHTSA ODI 11636664

The rear view camera is nonexistent at night, and I can't see a thing when parking.

NHTSA ODI 11628166

The contact owns a 2021 Hyundai Tucson. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed, but the vehicle failed to accelerate as intended. The check engine warning light was illuminated. The contact stated that the vehicle failed to exceed 20 MPH. The contact stated that the failure had occurred while driving on a busy highway. The contact safely pulled over to the shoulder of the roadway. The vehicle was then towed to the dealer, where it was diagnosed with engine knock sensor failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The manufacturer informed the contact that the repair was not covered under an unknown recall due to a lack of maintenance records. The contact was advised to contact the Better Business Bureau. The failure mileage was approximately 60,000.

NHTSA ODI 11627513

My check engine light came on in the vehicle and immediately the acceleration declined and I wasn’t able to go above 50 mph. I brought the vehicle to the dealership to which the code 1326 came up. I was told it is a rod bearing engine failure and I need a new engine for the vehicle. I was also told my vehicle doesn’t qualify for the recall already made for this damage and code number.

NHTSA ODI 11608558

The driver side and center seat belts in the back seat don’t secure. The buckle just slides back out. They’ve apparently been like that since I bought the car in 2020 and just recently had a passenger in one of those seats.

NHTSA ODI 11599840

Crank sensor went bad and engine needs rebuilt

NHTSA ODI 11594989

What component or system failed or malfunctioned, and is it available for inspection upon request? Steering column. How was your safety or the safety of others put at risk? Steering column would not disengage and remained locked up after the vehicle was started and in gear. This have caused me to almost get into a few collisions for the same issue. I have had friends and family, most recently my daughter, in the vehicle when these issues have occurred. I have almost collided with walls, cars, etc due to this issue. Has the problem been reproduced or confirmed by a dealer or independent service center? No. Despite the numerous videos I have presented documenting these incidents, they state they have been unable to reproduce. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Manufacture has not inspected the vehicle and keeps sending me to the local dealership where the vehicle was purchased from. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? Yes. During the issues where the steering column does not unlock or disengage, it displays a yellow light with a car and key symbol in it. During other issues I have experienced with this vehicle (phantom braking, acceleration / power issues, random dash controls turning on, and the electric e-brake failing to properly disengage, there have been no lots on the dash that were noticeable. Restarting the vehicle tends to rectify the issue.

NHTSA ODI 11585434

I was contacted by Hyundai last year about a possible recall on my engine so I brought it in October 2023 to have it checked out. I was told that everything with the car was fine. Fast forward to last week 02-21-2024 and my engine starts shutting off while driving ON THE HIGHWAY? I have it towed to a new dealership in Jacksonville FL Jenkins Hyundai I believe. They inform me that it is indeed the engine and it will be replaced for free under warranty. However, it’s been over a week and the parts for the car are still not available. I have researched online and found I am far from the only one this has happened to. I was not given a loaner car and they did not offer to pay for my rental but I was told they would reimburse me. I was also told that they would just pay every week for a rental car for me but then I was later told that that was a flat out lie. After March 7th when the rental car I have is to be returned I can no longer afford a rental car and will not have access to reliable transportation. This could potentially result in me losing my job. This is unacceptable and Hyundai should be investigated and held accountable for selling cars they know have faulty engines.

NHTSA ODI 11574644

Panoramic sunroof spontaneously exploded when driving on highway. No warning. Sounded like a gunshot. Had to pull over on the highway and clean off as much glass as I could so it did not cause injury or damage to other motorists. Looks like many other Tucson owners are experiencing similar issues. Has not been inspected yet as dealerships and insurance are closed today.

NHTSA ODI 11573848

AIR BAG ON DRIVERS SIDE DID NOT OPEN SAME THING WITH MY 2019 ELANTRA 3 YEARS AGO

NHTSA ODI 11559824

The back trunk latch is failing to unlock. The button can be heard and sometimes it sounds as if the motor is whining. After attempting to unlock the trunk by removing the cover on the safety wire and pulling it, this action was unsuccessful.

NHTSA ODI 11556586