2025 HYUNDAI IONIQ 5 Safety Overview

Component: POWER TRAIN,ELECTRICAL SYSTEM

"I am writing to document my case regarding my leased 2025 Hyundai Ioniq 5 XRT. Vehicle: 2025 Ioniq 5 XRT, VIN [XXX] Lease start / delivery date: Odometer: 4,368 miles Servicing dealer: Stevinson Hyundai, [XXX] Case number: XXX What happened: On Saturday, XXX, while I was driving, the vehicle displayed "Stop vehicle and check power supply" with the red 12V battery warning and the master warning light, and power was limited to approximately 25 mph. The high-voltage battery was at 66 percent. I was able to get the vehicle home at reduced speed, and Hyundai Roadside Assistance towed it to the dealer the same day. The symptoms are consistent with an ICCU failure, pending the dealer's diagnosis. Photos of the instrument cluster are attached. I consider a sudden loss of drive power at 4,368 miles to be a safety-related defect, and I have reported it to NHTSA. My situation: This is one of two vehicles in our household, and both of us need to get to work. The dealer is about 30 miles from my home. I am without transportation as of September 19. What I am requesting: 1. Written authorization for a rental vehicle starting immediately and continuing until my vehicle is repaired and returned, including the approved daily rate and how billing or reimbursement will work. 2. A parts availability check and estimated repair date as soon as the dealer confirms the diagnosis. 3. If the vehicle is out of service for an extended period, reimbursement of my lease payments for the time I cannot use it. 4. Confirmation of the warranty coverage that applies to the ICCU on this VIN, including any extended ICCU coverage. I am keeping a record of the days the vehicle is out of service, starting XXX. Please reply in writing so I have everything documented. Thank you for your help, [XXX] [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)"

Component: ELECTRICAL SYSTEM,ENGINE

"Full electrical power system failure. Heard a loud pop noise emanating from under the rear seats of the car. The power. Failure lights came on and the car lost power. We were able to get the car to slowly drive back to the garage where it completely shut down and was inoperable from that point on. Car has been towed to the local dealer for diagnostics and repair."

Component: ELECTRICAL SYSTEM,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM

"On 8/30 my vehicle experienced a power loss on a highway (reported here separately). I took the car to the dealership and they could not replicate the error and gave the vehicle back to me on 9/4. Later that day I had to drive 2 hours north to a wedding in the mountains. At 9:30pm my vehicle experienced a full drive power loss on an unlighted, curving, rural 2-lane mountain road in an area with minimal cell phone service. I tried to restart the vehicle several times and could not get any power. I called roadside assistance and had to wait over 2 hours in the dark on a winding mountain road for the tow truck to find us and then be towed 40 minutes away to the nearest dealership where my car is still sitting waiting to be looked at (2 hours away from where I live)"

Component: VEHICLE SPEED CONTROL,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM

"Driving home near my apartment, I had to join a busy highway from a full stop. I found a small gap and tried to accelerate to quickly merge into traffic, when my car made a high pitched alert noise and noticably did not accelerate beyond about 25 miles per hour on a 45-50mph highway with heavy traffic. I turned on my hazards and still ended up with a line up of cars honking behind me. Flooring the accelerator did absolutely nothing to increase my speed. On slight downhills I could get up to about 40mph but as soon as it leveled off my speed went back down to limping along. I was able to exit the highway at slow speed and tried to parallel park in an avaialble spot but could not reverse. I tried to drive on toward my house but the car could not make it up the hill even with the full accelerator pedal down. People were stuck behind me on my street so I turned the car off and back on again and the car appeared to resume normal operation and I was able to drive up the hill. I took the car to the dealer and they were "not able to replicate the error". They did fix a seat belt recall and updated the software for my ECU and said to come back if it happened again..."

Component: ELECTRICAL SYSTEM,VEHICLE SPEED CONTROL,FUEL/PROPULSION SYSTEM

"While driving this EV with cruise control on, the dashboard suddenly showed a message that “Smart Cruise Control conditions not met”. Attempting to re-engage the cruise control did not work and then the vehicle suddenly lost all propulsion (pressing the accelerator did nothing). The car quickly slowed to about 20 mph before we could maneuver it to the shoulder and turn it off. After a couple minutes, we restarted the car and drove it to the dealer. There were no other messages or warning lights or indicators. The dealer could not find anything wrong and asked us to pick up the car and resume using it. We use both a home charger (Emporia) and roadside (Tesla) chargers."

Component: ELECTRICAL SYSTEM,ENGINE

"I heard a loud popped sound from the back of my car while driving home. The car lost power and eventually died on the street. The war displacy came on to tell em to check electrical system. I originally bought th car from Capitol Huyndai in San Jose on September 2025 and it has 5992 miles. I towed the car to Dublin Hyundai for repair and confirmed the DTCP1A9096 for ICCU computer failing to charge the 12 v battery. It was a well known recall . I do not have any update on the repair since 8/25/26. I worry about my safety because the car can lose power while driving"

Component: ELECTRICAL SYSTEM

"In June 2025, I started a lease on a new Hyundai Ioniq 5 SEL. On August 16, 2026, I attempted to start the car, but it immediately beeped and flashed a warning about the 12V battery (I didn't manage to take a picture). It then showed signs of an electrical issue, like flickering interior and exterior lights. It was undrivable. A short time later, there was no power at all. I took out the old 12V battery and measured the voltage with a multimeter, and observed 3.7V. After putting in a new battery, the car operated normally."

Component: FORWARD COLLISION AVOIDANCE,LANE DEPARTURE

"When I use the adaptive cruise control and use the lane keeping assistance the system keeps giving me an error message that I'm not looking at the road. I believe this is a known problem and Hyundai pushed an software fix TSB 25-G1-16H in November 2025. My car appears to have the update but still repeatedly gives me the same error message. It's very distracting and since the error message flashes on dash where you usually see the camera monitoring right side of car that feature is impaired. I have had at dealership twice and while the technician knows its an issue there's nothing they can do without Hyundai's decision to correctly fix with software update. I am over 6' tall and where glasses, two things I can't change."

Component: POWER TRAIN,ELECTRICAL SYSTEM

"I started the car and got the warning "check electric vehicle system." The car then lost power. It would only go 27mph with the accelerator pedal pushed all the way to the floor. My safety was at risk because my car was not responding appropriately to driver input. The car is at the dealership as it is undriveable in this condition. This is the second incident with this vehicle within 6 months."

Component: ELECTRICAL SYSTEM

"ICCU failure. Failure happened while merging onto the road from driveway. Upon failure, 12 V battery was drained and car was immobilized. Prior to car mobilization dash read “Check electrical vehicle system” then many different failures appeared on the dash, then the car shut down. This event left us stranded on the road, unable to move to a safer location. Issue was confirmed with dealer and part had to be replaced. Part was original to the car and issue is known by the manufacturer but not being dealt with publicly."

Component: WHEELS

"While driving on normal paved roads, a small vibration was heard from the rear of the vehicle. A person near the car when leaving the origin that morning heard a minor clicking sound at low speed from the rear of the vehicle. The vibration at that point seemed to be related to the rural mountain road that had some rutting. Continuing to drive, but onto better roads, the vibration became louder and louder, and appeared related to speed. Nothing appeared loose when stopping to charge. Vibration became loud (above conversation), stopped to inspect. Removed aerodynamic cover from lug nuts on right rear, and found two lugnuts completely sheared off (fell out when cover removed), with a third hanging on at less-than-finger tight. Vehicle driven slowly to safe location where it was towed to dealer. Dealer reported that the rim was bent in addition to sheared lug nuts as well as a damaged wheel bearing."

Component: ELECTRICAL SYSTEM

"The vehicle was released to me as repaired by an authorized Hyundai dealer earlier the same day. While driving home, the vehicle entered reduced-power/turtle mode and lost propulsion capability. This is the third failure of the electrical/propulsion system in under three months on a vehicle less than one year old, and it occurred within hours of a warranty repair."

Component: ELECTRICAL SYSTEM

"While driving at 65–70 mph in rain, the vehicle emitted a repeated audible alarm from beneath the rear seat, then suffered a complete loss of motive power at highway speed. No warning light, message, or indicator appeared on the instrument cluster at any point. The vehicle was taken to an authorized Hyundai dealer the following day."

Component: ELECTRICAL SYSTEM,UNKNOWN OR OTHER

"Check electric system popped up. DTC: P1AD300 Critical hybrid/ev battery system fault involving abnormal cell voltage deviation 9,902 miles"

Component: ELECTRICAL SYSTEM,UNKNOWN OR OTHER,FUEL/PROPULSION SYSTEM

"My 2025 Hyundai Ioniq 5 experienced a complete and sudden loss of drive power at high speed, generating open fault code DTC P1A9096 (Internal ICCU Failure) [24V-204]. This failure completely matches the component and safety hazard profile under active Federal Safety Recalls 24V-204 and 24V-868 [24V-204].The vehicle was repaired at an authorized retail facility, Hyundai of El Cajon. The facility's un-finalized pre-invoice explicitly verified the ICCU failure code but deliberately omitted the federal safety recall context, routing the mechanical intervention under an internal manufacturer 'TSB 24-EV-004H' to hide the defect from consumer safety databases [24V-204].This represents a deceptive administrative effort to under-report active federal safety recall failures on newer model inventories across the E-GMP platform architecture [24V-204]. I am requesting a formal safety defect enforcement review into the manufacturer's regional reporting data."

Component: ELECTRICAL SYSTEM

"My car starting throwing a “check electric vehicle system” warning intermittently beginning on July 7, 2026 which went away when I restarted the car. This happened again on July 27, 2026 three to four times while I was driving. The car did not lose power. As I was going to dealer the warning cleared and no code showed up in my diagnostic history. On August 12, 2026, the car once again showed "check electric vehicle system” and would initially clear when I restarted the car. I then began having intermittent power. Floored, the car would only go 27 mph. Then it would speed up again, then slow again. I was not in “turtle mode.” Luckily, I was able to safely get the car to the dealership without having an accident. DTC P1A8D13 did show in my diagnostics. The technician found that the 12v battery input had melted at the ICCU. This is very dangerous and could have led to a vehicle fire. My 2025 is on its 2nd ICCU (now 3rd) and has not had any recalls, so this is very troubling."

Component: FUEL/PROPULSION SYSTEM

"SAFETY DEFECT REPORT: 2025 HYUNDAI IONIQ 5 HIGH-VOLTAGE BATTERY FAILURE On Sunday, July 5, 2026, at approximately 24,000 miles, the vehicle suddenly displayed a critical dashboard safety alert notifying me of an electrical propulsion failure and explicitly instructing me not to drive the vehicle. The sudden failure entirely disabled the vehicle's driving power and compromised its operational safety. The vehicle was removed from my possession via a flatbed tow on Wednesday, July 8, 2026, and delivered to Southern States Hyundai. On July 11, 2026, the dealership service technicians diagnosed a total high-voltage traction battery pack failure. The dealer opened Repair Order 9651579, and Hyundai Corporate approved a full warranty replacement of the $28,000 battery system. The vehicle remained out of service due to this safety defect for 21 cumulative days until the component replacement was completed on July 29, 2026."

Component: TIRES

"Two tires failed dramatically, (on two separate days, but separated by only 121 miles of driving), causing extensive damage the first time and causing a total loss the second time. The first tire has been disposed of, but the second is available still. Each was on the highway and luckily there was not much traffic so I was able to pull safely onto the shoulder each time. However, if I had not been able to get over, our safety and that of others was at risk if we had been involved in a collision. My safety and my that of my elderly, handicapped brother was at risk the first time especially, because this is an EV and at one point on July 4, 100 degree temperatures in the early afternoon in South Carolina, the electrical system had been damaged and we could not, for a few minutes, get doors or windows open. The components (tires) have only been inspected by repair shops. There was no warning either time. The tires are 235/55 R 19."

Component: ELECTRICAL SYSTEM

"While operating the vehicle, the instrument cluster displayed a “Check electric vehicle system” warning with a red vehicle-with-exclamation icon. The vehicle failed to charge when plugged in; state of charge was 90%. The vehicle was towed via Bluelink to an authorized Hyundai dealer. No prior issues and no damage history."

Component: STEERING

"Driving at highway speeds, the front end feels unstable. It feels as if the tires are jumping around and will move the car to the right or left. It is difficult to maintain control. I had it into the dealer shortly after I bought the car to complain about what I thought was a front end alignment problem. They didn't think there was an issue until they got it into the shop. They said afterwords that it WAS OUT OF LINE. But their fix did not hold, so I went in again for the one year maintenace and mentioned the problem, but they said it was not out of line. Well, The problem still exists. Something serious is wrong and needs to be fixed."