While driving on the highway in foggy conditions, the smart cruise control system and forward safety system suddenly shut off while I was going 70 miles an hour. This almost resulted in a car rear ending me due to the sudden deceleration. The following day, with clear weather, the same issue happened again despite nothing appearing to have caused this issue while I was driving. This is a very serious concern to suddenly stop on a highway.

- Allentown, PA, USA

On the morning of February 3rd, 2025, while driving, I heard a pop. A few seconds later, as I approached an intersection, a yellow warning appeared that instructed me to "Check the Electric Vehicle System". It minimized to a small caution light. I attempted to continue driving, pulling through the intersection; however, the vehicle had an abrupt loss of power; I was unable to proceed over 20-25 mph. In total no more than 2-3 mins passed from hearing the pop to loss of power. I pulled into a neighborhood, stopped the car, and consulted the owner's manual for direction on the warning light. While parked, and an estimated 8-10 minutes after hearing the first pop, I received a second warning, this time in red. It said "Turn power off immediately. Check power supply." I turned car off/contacted roadside, as advised in my manual, for a tow. After review at the dealership, I was originally told I needed a new 12V that it had died while I was driving. I authorized the replacement, though I also indicated to the service department that if that CAN happen, it really does not make sense AND there should be a different warning indicator for a failed 12v that could be replaced roadside versus instructing for a tow.However, after replacing my 12v the service advisor indicated that the car pulled codes and that the ICCU and its fuse seemed to have failed, which likely caused the damage to the 12v battery. After a few days of testing, my car was cleared for replacement of the failed ICCU by Hyundai's techline on February 10th. The dealer then provided a vehicle for my use while I await repairs. I was told a part could arrive the 18th or the 25th and the repair could take 3-4 days once the parts are received. It is still in shop with no updates. On 2/13/25 I filed a complaint to Hyundai; I have not received a response to date. All recalls for these issues had been performed on my vehicle in November 2024; we can no longer, in good conscience, use this vehicle. It is unsafe.

- Canton, GA, USA

While driving, the 'check EV system' light comes on, intermittently what will happen is that when stopped the car will put itself in park, when it is in park I can not get it out of park, thus unable to move forward, it has also happened while reversing (and not stopped). I need to cycle the car on and off a bunch of times in order for it to finally turn back on. This is very dangerous while on the road stopped in a busy intersection and has potential for a crash. I have brought it to a dealer 4 times and they do not know what is wrong and cannot fix it. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Charlotte, NC, USA

I was driving 75mph on the freeway and I heard a pop and then the electrical warning system on the car lit up. I lost power to the car and was only able to accelerate minimally. There was a warning of low battery and the vehicle was going to lose power. I turned on my hazard lights and was able to get to the exit and was able to exit the freeway safely. Once the vehicle lost power I was unable to open the charger door, start the vehicle, use any of the key fob functions and had to jump the 12V battery, only to die immediately after. There is no pre-warning to this happening, it just shows the alert and the car loses all power. There are also problems with the vehicle after being plugged in to charge and it says "Charging Unsuccessful", or stops charging after a short period of time. It also will not charge to full capacity at home or the charging station. I receive no warning lights or messages about why the charge is not working. It took weeks to get the vehicle into the dealer, making it extremely unsafe to drive and the error has almost caused a major crash. My vehicle has been at the dealer and has not been diagnosed with any issues yet. The dealer has provided me with a rental vehicle...in which now I'm paying for gas. Reading through these other comments...who knows how long it will be to get my vehicle back, yet I'm still making my payments...this isn't

- Chandler, AZ, USA

My vehicle was fully charged. About 1 mile after leaving my house, I received a warning message on my display (vehicle electrical system error or similar). Shortly after I received another message that power was reduced, then finally, "stop driving". I pulled into the nearest driveway and called roadside assistance. At that point, the vehicle was COMPLETELY dead. No lights or power whatsoever. I could not activate the car to shift into neutral. I had my vehicle towed to the dealership. They said it was due to a faulty ICCU and fuse. After about a week they were able to replace the ICCU, fuse and update the software.

- Belmont, VT, USA

I have a Hyundai Ioniq 5. I purchased it in July 2022 and have been driving it with no major issues except for a couple recall updates. On Monday, [XXX] I was driving home on the Highway when a warning light came on telling me to check EV Connection, it was an orange message. Then the light and message switched to red and displayed a battery symbol. The message said to stop vehicle and check power supply. My acceleration slowed down and I couldn't go above 25 mph despite attempts to speed up. There were many cars on the road when this happened, and I automatically turned on my emergency blinkers. There was a large 16-wheeler behind me that noted something was wrong and slowed down with his emergency lights blinking as well to support me. I panicked and found the nearest exit to come off the highway and before I could make it to the traffic light, the car shut off unexpectedly and completely stopped with no warning. Attempts to restart the vehicle did not yield positive results. After 2 hours of waiting for a tow truck in the middle of the road blocking traffic and waving people around my car, I was able to tow my vehicle to a dealership in NJ close by my house. As it was evening time, I left it at the dealership service center and dropped keys in drop box. I spent several days on the phone with Hyundai Service Center arguing to get my car checked as they told me that appointments were all booked, despite this being an emergency. I had no idea what was happening, but it was clearly inoperable, and I made that very clear. Finally, today, Thursday, [XXX] they confirmed that diagnostic testing showed ICCU failure. They advised that the part is on back-order, and they issued me a loaner for the time being. I have no idea how long this will take to fix. Luckily, I didn't have an accident, although very well could have with how quickly the issue escalated. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Sicklerville, NJ, USA

A warning popped up "Check electric vehicle system", then a few minutes later an error popup appeared "stop vehicle and check power supply" and the car would no longer go above 27 mph.

- Boulder, CO, USA

ICCU failed and Fuse failed, causing car to go into turtle mode, barely made it hope to have it towed to dealer

- Austin, TX, USA

Every so often when I am driving on the highway, the car just looses power and I may catch a message that flashes on my display, "Emergency Braking". The event last no longer than about a second. When this phantom braking happens, so far, it has not been so severe to feel dangerous just unsettling!

- Washington, DC, USA

Check electric charge error displayed, alarm sounding, loss of power to the vehicle while driving (limp mode).

- Longmont, CO, USA

When driving for a distance at higher speeds, power will suddenly drop to the zero point btw acceleration and regeneration. You can feel the car start to drag as the power drops. If you press hard on the accelerator to stop it from slowing, it will suddenly jump forward. This has happened now on several long trips where I am constatly fighting with the car to keep it powered and not slipping into the zero zone. When it leaps forward the lane assist will also grab control and make it difficult to control the car. The car also stops slowing consistently when I take my foot off the accelerator and will move/ jump forward more than is typical for an EV instead of slowing the way an EV should as it regenerates. This all happened twice previously on a long trip and today constantly during a three hour drive. Does not feel safe!

- Spring Valley, NY, USA

Was driving the vehicle in a local road and felt sudden drop in vehicle speed. Had to press hard the acceleration pedal to avoid any collision from behind. The vehicle could not gain enough speed in a ~45~60mile speed zone and driven ~2miles slowly to work place. The vehicle had to be towed to a local delearship as they suggested. The warning message was 'Stop vehicle and check Power supply' immediately after and changed to 'Check EV System' when started ~1hr later at the time of towing. The local dealership diagnosed it to be needing a new ICCU board, integrated charge control unit, which is in back order for ~2weeks (vehicle is still at dealership). In hindsight (after hearing recent news on ICCU failure of Ioniq5), the vehicle had a related issue in Feb 2023. At that time, the vehicle electrical system got blacked-out in my garage (it didn't respond to any button pressing with completely dark dashboard screen). It was towed to a local dealership since jump jump start could not fix it. They replaced a 12V battery for which local dealership could not give me convencing reason for the dead 12V battery.

- Newport Coast, CA, USA

Hyundai's connected car service (bluelink) suffered an outage that resulted in driver profiles on many Hyundai vehicles being deleted/reset. No notice was provided and the profiles were not recovered. As a result, the vehicles did not funtion as expected. Driver assist settings were set to default (steering, braking, and acceleration functions included). Hyundai provided instructions on how to set up a new profile in response rather than restoring the customer data to their personally owned hardware (car).

- Waverly Hall, GA, USA

Driving the car about at 45mph then I heard a pop sound from the rear of the car. Car displayed warning "Check Electrical Vehicle System." I pull over, shut it off, then restarted it. The "check Electrical Vehicle System" light stills on then an emergency message displayed 'Stop Vehicle and Check Power Supply.' When I tried to drive to a safe place I noticed the car would not drive faster than 25mph. If this would have happened in a highway this could have been a safety issue. Dealership confirmed that the Integrated Charge Circuit Unit (ICCU) needs to be replaced.

- Manvel, TX, USA

Accelerator failed to engage on two occasions. 5/18/2023: First while driving on highway at 70MPH. Car slowed down gradually and I pulled onto shoulder. 5/19/2023: Again the next day driving 35 MPH. Pulled off road onto private driveway. On both occasions I turned car off and back on and it resumed normally. Fortunately no accident or traffic problem. I brought car to the dealer (Country Hyundai Northampton) to be checked and they could not find a problem.

- Northampton, MA, USA

While driving on highway I got below messages -??Safety Functions are limited radar block warning message-?? Warning message went away after 15 minutes but then -??Stop Vehicle Check Power Supply-?? warning message appeared and vehicle slowed on highway and stopped after 2 miles. Dealer replaced ICCU and Fuse that controls high voltage (charges 12v battery from main battery).

- Portland, CT, USA

Hi! My vehicle went under a recall repair last month. Once completed, the acceleration significantly decreased in the ECO drive train mode. The other modes are working as before. I have been advised that this recall service was required by the NTSB. There are reports of this occurring on credible websites as well. I did report it to Hyundai, they didn't believe me. So, I am reporting this to you. Please fix my car!

- Littleton, CO, USA

The ioniq 5 has a one pedal driving mode, where the car will come to a complete stop without needing to press the brake pedal, similar to other EV's. In this mode, the gas pedal operates differently then in a conventional car - pressing the pedal approximately 1/3 of the way down represents neutral, where the car coasts. Pressing the pedal less then that - between 1/3 and not pressing it at all, applies braking power to the car, either through regenerative braking or the application of the physical brakes. The issue is, the brake lights on the rear of the vehicle do not light up when the gas pedal is depressed any amount. If you press the gas pedal as lightly as possible, the car will brake a fair amount but there is no warning to driver's behind that you are decelerating. I have twice been almost rear-ended, both times while slowing down in one pedal mode. I suspect the lack of brake lights until you take your foot fully off the gas pedal is a contributing factor. Other Ioniq 5 users have experienced the same issue.

- Manchester, NH, USA

I was driving on the highway using advanced highway assist and the car became completely unresponsive. I was traveling 75mph on a major highway with a semi behind me and one to my right in the slow lane. The car stopped accelerating and I was unable to resume driving. I was forced to coast to a stop on the side of the highway. I had my daughter with me and were I not able to safely maneuver between the semi trucks, we could have been killed or seriosuly injured in a high speed crash.

- Fishers , IN, USA

Vehicle parked and unattended. Shifter control unit failed and vehicle rolled away. Vehicle front damage.

- San Diego, CA, USA