What 32 owners told NHTSA about the 2017 Hyundai Sonata Plug-in

On 12/20/25, the car - a Sonata plug-in hybrid - failed to start. When I pushed the "start" button, the dashboard display lit up w many clearly irrelevant error messages. Each time I pressed start, somewhat fewer error messages blasted toward me, and finally, no response at all. On 12/21/2026, the tow driver said it was the 12-volt battery. He gave us a jump start and we drove a few blocks. However, it failed at the turn lane while waiting for the light to turn. We turned it back on, bought a new battery, had it installed. On 12/29/25, my husband was driving. He turned into the intersection with a traffic light. As he was making the turn, the car simply quit. No warning. The car was dead, and blocking traffic! He pressed the start button to turn off the car, then again to turn it on. He was able to complete the turn and parked on the side of the road. By this time it had a "check engine" light on. He then drove slowly the few blocks back to our house. On 12/30/2025, the car was towed to a local mechanic. He said it threw the code PODE7, "almost certainly for a failed High Voltage battery." It was still under warranty, and we had the car towed to the dealership. After keeping it for 2 or 3 weeks, they confirmed the code and that the control panel needed to be replaced. We finally picked up the car (w new control panel) on 2/20/2026. In the meanwhile, we looked up Hyundai control panel repairs on a reddit forum. We found lots of chatter about it. Turns out it's a recognized problem in Sonata and Ioniq EV and PHEV's! Clearly, a car failing in the middle of an intersection, highway, etc is a safety problem and needs to have repair/replacements made BEFORE THEY HAPPEN!

NHTSA ODI 11737182

I am reporting a serious safety issue involving a 2017 Hyundai Sonata Plug-in Hybrid (VIN: [XXX] ), originally purchased in California. While driving at approximately 70 mph on a highway, the vehicle suddenly lost all propulsion without warning and rapidly decelerated. This created a dangerous situation with surrounding traffic and put me and my family at risk. I had to quickly maneuver to the shoulder to avoid a potential collision. The vehicle was towed to an authorized Hyundai dealership in Utah, where it was diagnosed with a failure of the high-voltage battery system. I was informed that the battery requires replacement. This type of sudden loss of propulsion at highway speed is extremely hazardous and could result in a crash, injury, or fatality. There were no prior warnings indicating an imminent failure of this severity. Given the safety risk associated with unexpected loss of propulsion, I am concerned this may represent a broader issue affecting similar vehicles. The vehicle is equipped with an interior camera, and video of the incident can be provided if needed. I respectfully request that this issue be investigated as a potential safety defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11734703

To the National Highway Traffic Safety Administration, I am filing this formal safety complaint regarding a dangerous engine failure incident involving my 2017 Hyundai Sonata Plug-in Hybrid. Description of Incident: While traveling on CA-85 near Mountain View, California, at approximately 65 miles per hour, the engine suddenly and without warning lost all power. The vehicle began to slow down involuntarily in active highway traffic, creating an immediate and serious risk of rear-end collision. The driver had no ability to maintain safe highway speed or accelerate out of danger. The vehicle had to be towed from the scene to the dealership. There was no warning light or prior indication that engine failure was imminent. The failure was sudden, complete, and occurred at highway speed in heavy traffic conditions. Safety Risk to the Public: This incident represents a significant and ongoing public safety hazard. A sudden, unpredictable loss of engine power at highway speed — with no prior warning — places the driver, passengers, and surrounding vehicles at serious risk of collision. This is not an isolated mechanical inconvenience; it is a life-threatening failure mode. Known and Documented Defects: The 2017 Hyundai Sonata Plug-in Hybrid has been the subject of multiple recalls and class action litigation related to engine defects. My incident is consistent with the known failure patterns documented in those proceedings. Despite this history, Hyundai Motor America has denied my warranty claim, citing missed services — a characterization I dispute, as the vehicle was serviced exclusively at an authorized Hyundai dealership whenever the onboard system indicated service was due, and no technician ever identified or disclosed any engine damage during those visits. Request to NHTSA: I respectfully request that NHTSA: 1. Open or expand an investigation into engine failure incidents in the 2018 Hyundai Sonata Plug-in Hybrid 2. Investigate whether a recall is warranted

NHTSA ODI 11725213

While driving car stuttered check engine light and check hybrid system flashed. Check engine lights stayed on until getting home. Next day. I scanned and code p0b68 was set.

NHTSA ODI 11686903

While driving at a high rate of speed propulsion to the vehicle suddenly and without warning ceased, the electric and internal combustion engine were non-responsive (ICE stopped; hybrid motor didn't provide propulsion), the warning light said "Check Hybrid System. Turn off engine" I was put at risk because I was traveling at highway speed and was given no warning before the vehicle shut down. This has occurred nine times, I've reported all to Hyundai, they have had the car in the shop three times, the issue is not fixed. No, despite ODB2 error codes, the car has not shut down while a dealership is driving it. Yes, the vehicle has been inspected multiple times by Hyundai. Yes, always "Check Hybrid System. Turn off engine", in almost all cases the check engine light comes on after that, and in some cases additional lights such as "auto hold". This first occurred in Dec 2023, I was told the car was fixed (it wasn't) and happened again in October 2024. I haven't been able to drive my car since then.

NHTSA ODI 11648675

While driving the 2017 Hyundai Sonata Plug-In Hybrid, the car will begin to stall, a rapid number of audible beeps will start, the "Check Hybrid System" notification will pop up on the dashboard, and the "Check Engine Light" appears.. The car therefore cannot be driven anymore, and I am forced to pull over to the side. In order to fix the issue temporarily, I need to turn the car off and turn it back on again. Once this is completed, both the "Check Hybrid System" and the "Check Engine Light" disappears and the car can be driven again. An OBD Scanner is unable to find exactly what is going on as the "Check Hybrid System" and the "Check Engine Light" no longer appear. This has happened 4 times now within the span of 3 months. The people at risk are me (the driver), my passengers, and potentially everyone else on the road in my nearby vicinity as the problem occurs. This problem has been confirmed by the dealer in their Hybrid vehicles. This vehicle has not been inspected yet but that is an ongoing process.

NHTSA ODI 11579536

I was driving the vehicle with 2 other occupants onboard on [XXX] towards US-101. The EPS warning light already came on after entering [XXX] from [XXX], but initially, I didn't think it was much of an issue. As I merged to the right lane in preparation of entering the highway, the steering began to feel very stiff, so I immediately made a right turn into a local street when there was a little bit of steering left. As soon as I pulled over, the steering locked up completely, and both the EPS warning light and the dash display's lane-departure system warning were activated. Luckily no other vehicle or humans were endangered at the time. I put the car into park and powered it off. When I powered it back on again several minutes later, the issue resolved itself and I was able to continue driving with normal steering, and steering remained normal after several power on/off cycles which included both local and highway driving. Come to think of it, ~3 months before this incident happened, I already noticed occasional stuttering of the steering wheel and humming of the EPS assembly when the car is stationary or at low speed. I took the car to a third-party repair shop on the next day since the Hyundai dealership appointment is a week away at the earliest. They ran diagnosis before telling me that the steering sensor in the EPS motor assembly failed, and this happened very frequently for 2017 Sonata Plug-in hybrids. This happens so often, apparently, that Hyundai issued service bulletin [XXX], but this very much looks like a recall to me, as when the system fails, steering is lost completely, and could cause great harm to myself as well as the occupants onboard, not to mention other vehicles around me. I was lucky that it happened before I entered the highway and also had a place to pull over. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11568255

Vehicle lost power in freeway. Complete power failure. Early crashed into. Vehicle coasted to off ramp and towed away.

NHTSA ODI 11567254

About 3 weeks ago I had just left my house, battery fully charged and gas tank full. I was coming down a hill to a stop sign and started braking. Suddenly the car seemed to lose power and essentially stopped moving. There was an error on the dash saying "hybrid system failure". There was barely able enough power to slowly pull the car over to the side of the road. I turned off the car and checked the battery in the trunk - I didn't see any obvious concerns. My husband got there 10 minutes later and we tried turning the car on again. It came on fine but there was an engine warning light. We were able to drive it without difficulty back to my house. I was unable to get a timely appointment at my local Hyundai dealer, so a couple days later My husband drove it to a local garage to see if they could figure out what the problem was. When he turned the car on again the engine light was no longer on. However, at the garage they were able to pull up a history of the car alerts and it confirmed that it said hybrid system failure. I have done some research online and it sounds like there was a recall on Hyundai sonatas hybrids for 2017 but I did not see a recall for the plug-in version of the hybrid. I searched online, however, and there were many other owners of Hyundai sonata plug-in hybrids that reported the same incident. I am hoping that a recall gets is issued for the plug-in hybrid as well so that more owners don't have the same problem. If I had been driving on the highway at 65 mph in a middle lane and my engine suddenly lost power it could have been fatal. Oh - one other recent problem I had that I'm not sure is related is that my car recently started losing electric miles very quickly. From the time it was purchased until a few months ago, it was losing plug-in miles at about 1 mi per year (i.e. each year a fully charged battery gave me 1 mile less). Then about 6 months ago it started losing electric miles very quickly - about 1/mo. Dealer said it was normal aging.

NHTSA ODI 11563470

Occurrence: This has been a recurring issue for over a year (over a year, might be closer to two years now) for our PHEV Sonata. It has happened approximately 10 times. Problem: Total engine shutdown when driving the car. "Shut down engine" type error message pops up and cannot accelerate. Steering still works, but it can be hard to pull over due to lack of engine power. The car can be restarted after shutting down, but must first come to a complete stop and into Park. Safety Issue: The car stops working. Obviously, this would be quite dangerous on a busy road, a highway, or if you were taking a left turn, etc. Confirmation: The dealer indicates that the hybrid battery is a problem and should be replaced. However, due to supply chain issues, we have been waiting for over a year for the replacement. **** Reproduction Steps: **** We have found that it is most likely to happen with a fully charged battery and a sudden braking action. I suspect the issue happens when trying to charge the battery but due to its condition, it shuts down instead. It tends to happen: 1) Full Charge: Battery is fully charged overnight or "topped up" to full charge 2) Sudden Braking: Having to brake hard, such as being cut off. We have found that adjusting charging and driving habits has reduced but not eliminated the issue. Suggestion: I would suspect that having some electrical component to prevent a sudden overcharge might eliminate this problem (shunting excess current or turning off regenerative braking for sudden stops). Warning Messages: A warning message is seen, but it happens at the same time the engine is shut down and disappears before you could take a picture of it (as you are busy trying to do an emergency pull over).

NHTSA ODI 11520782

My 2017 Hyundai hybrid PHEV vehicle stuttered and failed to accelerate when the gas pedal was depressed and a warning light indicated a problem which was confirmed as a failed battery in January 2023. I was advised by the Hyundai Sonata service center 13 weeks ago that the vehicle was unsafe to drive due to a defective battery. They have not been able to replace the battery or provide an estimate of when the replacement battery will be delivered. The battery has a lifetime warranty but the Hyundai company and dealership is not providing a loaner vehicle or reimbursing me for rental vehicle while the unsafe vehicle sits in the service center for more than 3 months. Please help.

NHTSA ODI 11518172

Problem began Dec. 2021. Has occurred on 16 occasions since then. Warning light "Check Hybrid System; Turn off Engine" comes on while driving. The car then shuts off the engine and there is a 100% loss of motive power. Sometimes is associated with very rough braking with the car "knocking'." On 3 occasions there has been partial/near complete loss of braking power. All incidents have occurred while under power, so far all while under 45 mph. No accidents yet. Two near collisions from the rear. Hyundai was notified of the problem Dec. 2021/Jan. 2022. After a month of testing they stated the car needed a new plug-in hybrid battery. One was not available and due to "supply chain issues" is still not available 15 months later. Dealership provided a loaner vehicle Jan to Sept. 2022. They requested their car back and Hyundai initially agreed to cover the cost of a rental car. I rented a car for 6 weeks in Sept.-Oct. 2022 at which point a new case manager informed me that Hyundai would not pay for a rental vehicle any longer (note: they did reimburse me the cost of those 6 weeks rental). Hyundai is well aware of the safety issues involved in driving this vehicle. However, they have chosen to ignore them. Their attorney, in a letter to the Ohio Attorney General's Office, blamed the lack of a plug in hybrid battery on supply chain issues (letter was Nov. 2022, at which time the battery was supposed to be available March 2023) and only stated that my vehicle was "drivable." Another warning message "High System Temperature; Switching to Hybrid Mode" has been occurring for a couple of years periodically. Since October 2022, the malfunction indicator lamp is always on and 99% of the time the "Check Hybrid System!" warning light also comes on after about a minute after starting the vehicle. On 3 other occasions the vehicle has entered into "limp home mode" instead of complete shutdown.

NHTSA ODI 11516024

The vehicle has stalled in traffic numerous times since I bought it in 2016 creating a traffic safety issue. Without warning the lights on the dash will flash and the car dies. I have worried each time that traffic behind me would collide with my car. #1 1 1/2 years into ownership this occurred. They replaced part of the EV charging system that was overheating on the cars. (RECALL) # 2 1 /2 years into ownership the air-conditioner failed and the car stalled in traffic due the air-conditioner failing. (REPLACED UNDER EXTENDED WARRANTY) # 3 Last year I complained that a Hybrid Overheat Message would come on switching to EV mode and the transmission felt like it was slipping occasionally, and the battery only held 20 miles of charge, rated for 27. They refused to change the battery system under the lifetime warranty. #4 Last summer car stopped charging (REPLACED INVERETER UNDER EXTENDED WARRANTY) This month car stalled on the roadway, lights flashed on dashboard. Could have been rear-ended, Had to coast to a stop and restart the car. Took to dealer the said the replaced an EV computer for 5K (REPLACED COMPUTER UNDER EXTENDED WARRANTY) 3 days later same issue, stalled on busy street without warning. Took to dealer and the replaced the cars main battery, charging me $450.00 3 Days later it stalled again without warning in traffic, It's not back in the shop. THIS VEHICLE HAS MAJOR SAFETY PROBLEM. IT'S EXTREMELY DANGEROUS TO HAVE A CAR STALL IN TRAFFIC WITHOUT ANY PRE-WARNING. THE DESIGN IS DEFECTIVE. THE CARS NEED TO BE RECALLED AND BOUGHT BACK AT FULL PRICE BY THE HYUNDAI.

NHTSA ODI 11506083

The engine started knocking on the freeway and all the lights in the car went off. The engine failed and I barely made it off the freeway. I was almost hit by two cars trying to get to a safe place. The engine has the same issue as the other morsels that have recalled the engine for the same rod failure issue but Hyundai has not extended the recall to the plug in hybrid. This model also bends to be recalled because it is a danger to all owners and other drivers. Hyundai declined to repair the defective engine.

NHTSA ODI 11454311

On cold mornings, during the first start of the day, and while going downhill, the internal combustion engine comes on while running on electrical power from the battery. This is understandably to heat up the engine to ideal temperatures. But within a minute, the car gives a hybrid battery error, fully loses power requiring to be stopped immediately. This is obviously dangerous anywhere but particularly downhill. The car requires to be restarted after pulling over 1-3 times until the engine / battery reach ideal temperatures. Then the car runs as expected. The dealership has been unable to diagnose the issue and chalked it up to an unrelated recall - which has been fixed, but the issue still occurs risking the safety of the people inside the car and around.

NHTSA ODI 11451054

While driving on surface streets (10-15 MPH) about 5 minutes out from our house, the accelerator stopped working properly and a warning popped up along the lines of "Hybrid HEV warning: Please shut off engine and restart." Since there were no other cars behind us, we were able to thankfully pull over without too much trouble. However, if we had been on a highway this would have been incredibly dangerous, as we would have lost speed quickly and had no safe way to pull over. There were no warnings prior to this happening on that day. The car just sudden stopped working and then lights popped on. Using an OBD reader, the issue code was P0DE7: Hybrid/EV Battery - Cell Voltage High. We are going to the dealer at the earliest appointment to have it looked at, and the car is clearly not safe for anything but surface roads with easy pull-offs. Related Items: A week or so ago, we had an incident where the car was a bit sluggish to accelerate after a right hand turn (e.g., needed to take foot off the gas, then put it back on after a moment to accelerate). However, no check engine light came on and the car ran fine after. A second potential related item was that the expected mileage on battery-only had reduced from about 27 to 23 miles on a full charge. This occurred within the last two months before this issue.

NHTSA ODI 11450701

The contact owns a 2017 HYUNDAI Sonata Plug-In Hybrid. The contact stated while driving approximately 35 MPH, the vehicle started making a loud knocking sound. The contact pulled over and noticed an excessive amount of oil underneath the front of the vehicle. The contact took the vehicle to a certified mechanic who diagnosed that there was a hole in the engine block. The mechanic showed the contact a piece of metal that had fractured from the engine. The contact stated that three days later while driving approximately 25 MPH, the vehicle stalled. The vehicle was towed to the dealer who confirmed that the vehicle was not included in NHTSA Campaign Number: 21V727000 (Engine). The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 76,000.

NHTSA ODI 11434553

On August 31st 2021, While driving my 2017 Hyundai Sonata PHEV on interstate 95 the check engine and hybrid system warning lights came on and the car simultaneously lost power for 3-4 seconds, which caused a decrease in speed from 65 to approximately 50 mph. There was a tractor trailer behind me but thankfully it braked to avoid striking my car. The car regained partial power and I was able to drive it home. I took the car to the dealership to have it repaired. The dealer diagnosed a faulty battery management system, and replaced this component after 17 days. On September 25, while driving on a street the car once again lost power for 3-4 seconds, with the check engine and hybrid system lights simultaneously illuminated. There was a recall on my vehicle several years ago to prevent this dangerous problem. I had the car repaired at that time but clearly the problem was not fixed as my car has subsequently lost power on two separate occasions, in a manner that could have easily caused a crash.

NHTSA ODI 11434360

The trunk will not open by any means, at times it can be opened, but the emergency release does not work. If anyone gets in, they cannot get out, especially with the Hybrids which do not have fold down back seats. Federal mandate states the trunk must have an operational emergency release, but with the trunk latch issue, the emergency release does NOT work.

NHTSA ODI 11422230

THE TRUNK LATCH NOT LOCKING. OPENED TRUNK IN DRIVEWAY, TRIED TO CLOSE TRUNK AND IT WOULDN'T LOCK/CLOSE.

NHTSA ODI 11399647

TL* THE CONTACT OWNS A 2017 HYUNDAI SONATA PLUGIN HYBRID. THE CONTACT STATED WHILE DRIVING 50 MPH, SHE HEARD AN ABNORMAL SOUND. THE CONTACT STATED THAT THERE WAS NO WARNING LIGHT ILLUMINATED. THE CONTACT DROVE TO HER RESIDENCE. THE CONTACT STATED SHE HAD THE VEHICLE TOWED TO HARRISONBURG FORD, INC. (3155 S MAIN ST, HARRISONBURG, VA 22801; (540) 434-0700), WHERE IT WAS DIAGNOSED WITH NEEDING THE ENGINE TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER HAD NOT BEEN INFORMED OF FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 75,000.*DT

NHTSA ODI 11377893

I WAS DRIVING MY HYUNDAI 2017 SONATA PLUGIN HYBRID ON THE HIGH WAY IN HEV MODE AND SUDDENLY I FELT SEVERE VIBRATION IN MY CAR. THEN I CHANGED MY ENGINE TO EV MODE AND IT WAS FINE. ENGINE LIGHT CAME ON. EVERY TIME THE GAS ENGINE CAME ON THE CAR STARTED VIBRATING AND NON RESPONSIVE TO GAS. I DROVE ABOUT 10 MORE KM TOWARDS HOME ON ELECTRIC ONLY ENGINE AND THEN GOT IT TOWED TO THE DEALERSHIP. IT FELT LIKE ENGINE LOST ITS POWER. I RECENTLY CHANGED THE VOLTAGE PROTECTION DEVICE ON THE CAR AS A RECALL. ALL SERVICES WERE DONE ON TIME AND CAR HAD ONLY 33000 KM.

NHTSA ODI 11210126

THE SHARK FIN ANTENNA COVER CAME OFF THE VEHICLE. WHEN I PARKED THE CAR, AFTER DRIVING ON THE HIGHWAY, I NOTICED THAT IT WAS GONE. THIS DEFINITELY CAN POSE A DRIVING HAZARD IF IT COMES OFF THE VEHICLE WHILE DRIVING ON THE HIGHWAY. I NOTICED THAT WHAT WAS LEFT OF THE BASE MOUNTS APPEARED TO BE CRACKED WHICH RESULTED IN THE FIN BREAKING FREE. THIS DEFINITELY APPEARS TO BE A MANUFACTURING DEFECT. IT'S APPROXIMATELY A $500 COST AT THE DEALER TO REPAIR. THIS SHOULDN'T HAPPEN AFTER TWO YEARS OF CAR OWNERSHIP. IT WILL GET VERY COSTLY TO REPLACE THIS AT THE DEALER EVERY TWO YEARS. BASED ON OTHERS' EXPERIENCES, THIS APPEARS TO BE A COMMON OCCURRENCE WITH THIS VEHICLE.

NHTSA ODI 11194338

WHILE VEHICLE IS IN MOTION AT VARIOUS SPEEDS WITH CRUISE CONTROL ENGAGED CLIMBING UP ON HILLY OR STEEPER GRADES THE VEHICLE ACCELERATES ON THE DASH AT NEARLY 100 PERCENT POWER ACCORDING TO THE HYBRID TACHOMETER. THIS INCREASE IN POWER SURPASSES WELL OVER THE SET CRUISE SPEED. FROM WHAT I HAVE NOTICED ITS 6-10 MPH CLIMBING PAST MY SET SPEED. THERE IS ALSO A LONG DELAY IN POWER RESTORATION AFTER COASTING DOWN HILLS. I FOUND IT TO BE EXTREMELY DANGEROUS WITH THE VEHICLE AT 100 PERCENT POWER BECAUSE IT COULD CREATE A SITUATION IN WHICH YOU COULD POSSIBLY REAREND ANOTHER DRIVER OR LOSE CONTROL IN NORMAL OR ADVERSE DRIVING CONDITIONS, RESULTING IN INJURY OR LOSS OF LIFE. IN ADDITION THE ISSUE COULD LEAD TO A TRAFFIC INFRACTION. MY STATE HAS A LOT OF SPEED CAMERAS. THIS PROBLEM HAVE RESULTED FROM THE RECENT RECALL WHERE HYUNDAI INSTALLED A NEW BATTERY MANAGEMENT SYSTEM. THE VEHICLE HAS APROXIMENTLY 16400 MILES ON IT.

NHTSA ODI 11192026

THIS IS THE PLUGIN HYBRID MODEL. THE LITHIUM ION BATTERY CANNOT BE CHARGED SOMETIMES DUE TO OVERHEATING CONDITION. IF THIS IS NOT FIXED, IT MIGHT CAUSE A FIRE OR EXPLOSION. SOMETIMES, IT WILL NOT LET YOU CHARGE. IT WILL NOT EVEN LET YOU TURN OFF THE CHARGE SCHEDULE TO CHARGE. SOMETIMES, IT STOPS CHARGING DUE TO THERMAL PROBLEM. HYUNDAI IS NOT TAKING RESPONSIBILITY TO FIX THIS. ATTACHED PHOTO DOCUMENTED THAT IT DID NOT ALLOW ME TO SWITCH OFF THE CHARGE SCHEDULER TO START CHARGING. I HOPE HYUNDAI WILL ADDRESS THIS PROBLEM BEFORE THE CAR BURNS UP OR EXPLODES.

NHTSA ODI 11102589