2025 Hyundai Ioniq 5 Speed Control & Cruise Problems

I was driving my vehicle on a freeway with 3 passengers when i heard a muffled pop or thud from behind me. A rear passenger confirmed that it came from beneath the rear seat towards the left side of the car. The vehicle speed immediately dropped to less than 40 mph and a warning message appeared on the dash "Check electric vehicle system". I later noticed a red battery icon appear on the left of the dash. I pulled over after leaving the freeway and attempted to resolve the issue by turning off the car, then restarting it. The notice and red battery icon still appeared. I feel that this sudden reduction in speed is a safety issue because I could have been driving at a higher speed (65-70 vs 45-50). Following cars may not have been able to stop in time, or I cuold have been forced to attempt to get off the road by entering lanes with vehicles travelling at a much faster speed. I was about 5 miles away from home on the start of a 400 mile trip so decided to turn around. Back at home I discovered that a new DTC code had been thrown during or after this event - P1A9096. I transferred to another person's cart to complete the trip, and on return arranged for the car to be transported to a manufacturer recommended dealership to check the issue. The Dealership service department conducted diagnostic tests and determined that the issue was caused by an ICCU failure. The have placed an order for a replacement ICCU unit and fuse. Prior to this event there had been no dash light warnings or trouble codes thrown.

1. Component/System: One-pedal driving / regenerative braking (i-Pedal mode). Vehicle is available for inspecti On three separate occasions since leasing the vehicle in April, 2025, the vehicle failed to decelerate when i-Pedal mode was active and I fully released the accelerator pedal. Instead of slowing immediately as expected, the car continued maintaining speed for a few seconds before eventually reducing speed. In all instances, the accelerator pedal returned fully to its default position, and my foot was completely off the pedal. My foot was hovering over the brake and prepared to brake manually. This unexpected continued acceleration created a safety risk, particularly in situations where I anticipated immediate slowing. Safety Risk: This behavior increases the risk of rear-end collisions or reduced reaction time in traffic. It causes uncertainty in vehicle response and requires sudden manual braking when the system fails to operate correctly. Inspection/Reproduction: The dealership has inspected the vehicle and has denied existence of any issues. Warning Lamps/Messages: No warning lamps or messages appeared before or during the events. ⸻ 2. Component/System: Blind spot monitoring / driver assistance sensors Since acquiring the vehicle, the blind spot monitoring system routinely activates warnings when vehicles are more than one lane away, not in the adjacent lane. This results in frequent false warnings, especially on multi-lane highways. Safety Risk: The false alerts cause distraction and hesitation during lane changes. The system startles the driver and forces additional visual checks beyond normal safe driving practice, increasing cognitive load and reducing confidence in the system’s accuracy. Inspection/Reproduction: This behavior is frequent and occasionally reproducible. Warning Lamps/Messages: System behaves as if detecting vehicles in blind spot even when lanes are clear.

When in cruise control, the driver attention warning message appears regardless of where my eyes might be, whether I am wearing glasses or sunglasses or not, with nothing obstucting the sensor, with the steering wheel adjusted higher or lower. I have since May of 2025 tried to figure out how to get it to work properly to no avail. The warning continues to appear with an alarm ubntil it turns the motor off completely, even at highway speed causing an extremely dangerous situation. Additionally, I depend on the cruise control to help me maintain a safe, legal speed. This malfunction, rather than being a safety feature, is a distraction to safe driving. It CAUSES distraction, rather than provide safety. Hyundai is fully aware of this deficiency, yet has not addressed it I know that Many have experienced this smae problem. It is time for a recall to remedy this problem.