Home · 2021 Hyundai Tucson Fuel Cell · Complaints

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

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (75)Crash / fire / injury (8)Engine (36)Brakes (12)Electrical system (11)Fuel system (8)Transmission & drivetrain (7)Driver assistance (6)Airbags (2)Body & structure (2)Engine & cooling (2)Lane Departure (2)

Newest first · 75 complaints · page 1 of 3

Jul 22, 2026

This vehicle burns oil at an alarming rate. I am getting oil changes every 3K miles, and when I take it in, the dipstick is dry. I receive no oil lights to tell me it is low. I just had to get spark plugs and the mechanic at the garage told me this was due to the oil consumption issue in these vehicles. I am at 71,000 miles.

NHTSA ODI 11752252

Jul 18, 2026Engine

I was driving down [XXX] from my house.My engine light started to flash.I tried to accelerate my car barely went 10 miles an hour.I got Home 2 minutes later.There was major knocking.I had the car towed to [XXX], Hyundai, the only code that is showing up on the diagnostics, is P1326 there is an open class action lawsuit for this exact code. For the rod bearing failure, Hyundai is denying the claim, saying there's a gap in maintenance history on a car. I didn't own yet when I bought the vehicle. It passed a 190 point inspection. There's no way there was anything wrong with this vehicle.I am under fifty thousand miles , and if I was on the highway , it could've been deadly i could not accelerate. No other lights were on in the vehicle, except for the flashing engine light.I have already reported to the better business bureau and they have sent it to arbitration. I have contacted the escalation department for Hyundai.They opened up to separate cases.The agent that was assigned to me didn't even get the code from [XXX], they just denied the claim without it.I have the emails to prove that I had to give it to her. I have.\n All my maintenance history, but as you can see from the text message from XXX Hyundai, they are requesting maintenance for a car that wasn't in my possession yet. They're asking for dates from a year before I had the car, I bought it through EchoPark. I have everyone on my side including fFdelity , as I tried to go through Fidelity and they said they couldn't approve the warranty because of the class action lawsuit against Hyundai for that exact manufacturer malfunction. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11751238

Jul 10, 2026Engine

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The check engine warning light was illuminated. The vehicle was driven to the shoulder of the road before being driven to the residence. The contact’s neighbor checked the oil level and informed the contact that the oil pan was empty. The oil level was topped off. The contact stated that the vehicle was not due for an oil change for another 200 miles. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact was informed that there was no oil in the oil pan. The contact was informed to provide the vehicle service records. The contact stated that the failure was a manufacturer's failure. The manufacturer was made aware of the failure, and two cases were filed. The failure mileage was approximately 44,807.

NHTSA ODI 11749638

Jul 1, 2026Driver assistance

Forward Collision Avoidance Assist is on and will not go off. Only has 16,900 miles and is newly out of warranty except for 5yr 50,000 bumper warranty. Dealer at Allen Turner says noat way they will cover this because my Vin is not listed in the latest recall. This vehicle was purchased new and has been maintained as required by manufacture . So, I am [XXX] and have purchased new Hyandais before. I do not at this time in my life have the means to fix this issue. Is there any help on this from Manufacture since this is so newly out of warranty and low mileage. I do not know what to expect as to causing a road accident and hurting myself or someone else. My phone is [XXX] and address is [XXX] Email is [XXX]. Kind regards. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11747598

Jun 25, 2026Driver assistance

Forward crash avoidance system keeps activating causing the car to brake on it's own. This was previously fixed on my car once back in 2022 and now in 2026 it is happening again. I have been trying to communicate with Hyundai regarding additional years to current recall but their not going to even though they have known for years this was an issue and included older models than their current recall. This is not a one time issue this is the second time and until fixed it continously caused the vechile to randomly brake, it's going to get someone seriously injured or killed if they don't address it.

NHTSA ODI 11746359

Jun 17, 2026Visibility & wipers

My back windshield shattered unexpectedly

NHTSA ODI 11744687

Jun 11, 2026Driver assistance

The contact owns a 2021 Hyundai Tucson. The contact stated that upon starting the vehicle on several occasions, the message "Check the Forward Collison System" was displayed, and a collision warning light illuminated. The vehicle was taken to a dealer, where it was diagnosed that the forward-looking camera had experienced an open circuit, and unknown parts needed to be replaced. The contact stated that the failure was associated with NHTSA Campaign Number: 26V316000 (Forward Collison Avoidance). The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 69,493.

NHTSA ODI 11743425

Jun 9, 2026EngineFuel system

My car is burning oil. I have returned multiple times to have it serviced and checked for leaks, but no leaks have been found. Before reaching the recommended 3,000-mile oil change interval, the oil level drops below the minimum mark on the dipstick. In addition, my engine has started making a knocking noise, which is very concerning.

NHTSA ODI 11743079

May 12, 2026Electrical systemEngine

Vehicle stalled approximately 15 times between April 17 and May 4, 2026, including once on Interstate XXX at approximately 50mph with minor children ages [XXX] and [XXX] in the vehicle. The oil and battery lights illuminated simultaneously at each stall. Diagnosed as ABS module failure first, then left front wheel speed sensor failure on the 2nd occasion, both confirmed by a Hyundai dealership. Multiple warning lights illuminated, including check blind spot and anti lock brake system messages on the dashboard BUT no error codes following the 2nd repair. The vehicle has been inspected and repaired twice by the manufacturer’s dealership with a 3rd repair currently pending as of May 11, 2026. An open case has been filed with Hyundai Motor America regarding this issue. Issue remains unresolved and the vehicle is still at the dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11737345

May 7, 2026Engine

2 years ago I had the engine replaced. Now on this new engine which has approximately 29k. The mechanic is telling me that I need a new engine. I called Hyundai and their telling me that is not under warranty anymore. What can be done?

NHTSA ODI 11736406

May 4, 2026Engine

My 2021 Hyundai Tucson has experienced repeated engine-related failures associated with a knock sensor (P1326) fault that causes the vehicle to enter limp mode and lose power while driving. This issue has occurred multiple times at approximately 15,000, 17,000, 41,000, and 90,000 miles and has resulted in four separate incidents requiring towing. During these events, the vehicle suddenly loses power and cannot maintain normal driving speed, creating a hazardous condition while in traffic. The vehicle has undergone multiple repair attempts, including an ECM update and three knock sensor replacements. Despite these repairs, the issue continues to recur and no root cause has been identified. Hyundai has not provided a permanent fix and has advised continued operation of the vehicle unless the issue occurs again. This ongoing condition presents a safety concern due to the risk of sudden loss of power while driving.

NHTSA ODI 11735611

Apr 29, 2026Electrical system

In October 2025, while the vehicle was still under Hyundai’s 5-year warranty, an authorized Hyundai dealership diagnosed a significant electrical failure affecting the ABS/ESC system on my 2021 Hyundai Tucson. The vehicle was experiencing multiple dashboard warning lights, intermittent key fob malfunction, alarm system failure, and progressive electrical instability affecting safe operation. Dealer diagnostic trouble codes included C120001, C167581, and C164202, with technician notes stating “ABS sensor wiring harness fault found.” The dealership recommended replacement of the wiring harness, estimated at approximately $12,000, but no warranty repair was performed. Since the initial diagnosis, the condition has continued to worsen with additional warning lights and ongoing ABS/electrical system instability. The issue remains unresolved and continues to affect vehicle safety.

NHTSA ODI 11734552

Apr 3, 2026Fuel system

I just got an oil change and the oil was completely gone although there was no leak found. Not even a week later my oil is low again. There is smoke coming from the back pipes and the gas is burning out quickly. I just purchased the car last year

NHTSA ODI 11728957

Mar 26, 2026Engine

I already replaced 3 catalytic converters and I am at 31000 miles. They finally decided to do an oil consumption test but it passed. The other day my car started shaking and my ignition coil and spark plugs were also bad which somehow is related to my engine issues.

NHTSA ODI 11727243

Mar 23, 2026Engine & cooling

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at various speeds, the check engine warning light was frequently illuminated on the instrument panel. The contact had taken the vehicle to various independent mechanics and was informed that the engine was consuming an excessive amount of engine oil. The contact had taken the vehicle to a dealer for service, and upon inspection, the contact was informed that the engine needed to be replaced. The contact was provided with an estimate for the engine replacement. The manufacturer was notified of the failure but offered no assistance. The contact was initially informed that the vehicle was covered under warranty; however, the contact was later informed that there was no warranty on the vehicle. The vehicle was not yet repaired. The failure mileage was approximately 89,000.

NHTSA ODI 11726305

Mar 13, 2026Engine

While driving on the freeway, my 2021 Hyundai Tucson SE (72,021 miles) suddenly and without warning lost power and entered limp mode. I was able to safely maneuver to the shoulder and exit the freeway. The check engine light came on and is currently flashing. I took the vehicle to AutoZone where code P1326 was retrieved. I then took it to Pep Boys for a full diagnostic where P1326 was the only code present. The Pep Boys report states the vehicle requires immediate attention. The vehicle remains in limp mode and the check engine light is flashing. The vehicle is not being driven as it cannot safely reach freeway speeds. I contacted Hyundai Customer Care and was assigned Case # XXX. I also contacted a Hyundai dealership who attempted to charge a 225 diagnostic fee despite P1326 being a known Hyundai defect covered under recall/service campaign. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11724214

Feb 9, 2026Transmission & drivetrainEngineFuel system

The vehicle experienced a catalytic converter efficiency failure that was confirmed by an authorized dealership in January 2025. The dealer indicated the catalytic converter required replacement; however, the replacement was not performed, and the vehicle was returned to service with an unresolved emissions defect. Less than one year later, the vehicle developed recurring emissions system failure, loss of power, drivability issues, and repeated warning indicators. The vehicle is currently out of service while additional components, including oxygen sensors and spark plugs, are reported to be affected. The manufacturer is declining to replace the catalytic converter and is attributing the condition to oil consumption despite the prior unresolved emissions failure. The issue has been confirmed by dealership diagnostics and has resulted in prolonged loss of use of the vehicle. This appears to be a continuing engine and exhaust/emissions system defect that was not properly remedied when first identified and may affect safe operation of the vehicle.

NHTSA ODI 11716729

Feb 5, 2026EngineFire

The contact owned a 2021 Hyundai Tucson. The contact stated that while driving at 10 MPH, an abnormal clicking sound was coming from under the hood. No warning lights illuminated. In addition, the contact managed to pull over to the shoulder of the road, where white smoke was noticed leaking from under the hood, and the intensity was increasing while the smoke turned black. The local fire department arrived on scene to extinguish the fire. The source of the fire was not identified. It was unknown if a Fire report was filed. A police report was filed. No injuries were sustained, and medical attention was not sought. The vehicle was towed to the contact's residence. The vehicle was deemed a total loss as it was majoily consumed by the fire. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000.

NHTSA ODI 11715856

Jan 22, 2026Engine & cooling

The contact owned a 2021 Hyundai Tucson. The contact stated that immediately after purchasing the certified vehicle, the vehicle went into LIMP Mode while her grandson was driving approximately 65 MPH, and the vehicle decelerated to 7 MPH. The vehicle was towed to the local dealer who diagnosed that the NOX sensor had failed and needed to be replaced. The vehicle was repaired but while leaving the dealer, the failure reoccurred. The vehicle was towed back to the dealer who replaced a second NOX sensor and the catalytic converter. The contact stated that days after retrieving the vehicle, the failure reoccurred, and the vehicle was towed back to the dealer who diagnosed that the NOX sensor had failed for a third time, within several days of owning the vehicle. The vehicle was traded in. The manufacturer was notified of the failure. The failure mileage was 28,944.

NHTSA ODI 11712627

Jan 22, 2026Engine

I have been adding oil to this engine excessively for more than 3 years..I have had appointments with the dealer where they flat out told me bring it back when the engine fails.i finally got N appointment and was told the engine needed to be replaced.that was 2 weeks ago..they are now denying the claim...have had my car for 2 weeks..no loaner..and decided to deny what they told me

NHTSA ODI 11712752

Jan 19, 2026

I left my house this am in below zero temperatures. I drove to my daughter's apartment complex 41 miles away. I pulled into her underground parking garage and then heard a loud pop, followed by the rear hatch window imploding into thousands of pieces.

NHTSA ODI 11711943

Jan 9, 2026Engine

Oil Consumption problems

NHTSA ODI 11709979

Jan 9, 2026Engine

I am the original owner of this car and in June 2025 I brought my car to Hyundai from noises and they told me it had no oil despite me being up to date with oil changes on the vehicle. They told me they were going to do an oil consumption test and once they did that the engine was denied. 6 months later 3 days after an oil change and no check engine light on, the engine fails while I’m on the side of the highway. This car is not safe. Check engine light was not on and I am always up to date with my cars maintenance.

NHTSA ODI 11709985

Dec 23, 2025Engine

Oil light comes on between changes at about 1500 miles before needing one, oil does not show on dipstick and have to repeatedly put on in engine. Chance of engine seizing or jumping time.

NHTSA ODI 11706731

Nov 17, 2025Brakes

The issue started just before my vehicle had 60,000 miles on it and only occurred every once and a while but, now it happens more often. When braking at low speeds my car makes a hissing/buzzing noise and the pedal goes soft. We got to a dealership when it had 60,420 miles on it. The dealership had it for two weeks saying they have never experienced anything like this issue before. They even contacted Hyundai Tech to help them. No warning lights ever came on and that was my concern. Finally after two weeks they said my tone ring on my driver's front side was bad and causing a false 0 reading. When I asked why the warning lights didn't come on they told me everything was working like should. Then after I pointed out that they said it was reading a false zero they were like no that must have been a typo its reading four miles under the rest and that's causing the abs system to activate. I'm from Ohio so I know what my abs sounds and feels like when it activates. It's a pulsating feeling not a soft pedal. When my abs truly activates my traction control light comes on. As I stated no lights have ever come on. This issue causes longer stopping times. There hasn't been any accidents because my wife and I try not to drive it. It's going to a third shop to try and figure out the issue. Yes the vehicle is available for inspection.

NHTSA ODI 11699883

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Working with the data? Download all 75 complaints as CSV · fetched from NHTSA July 25, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2021 Hyundai Tucson Fuel Cell verdict →