Hyundai Ioniq 5 Acceleration Problems

Acceleration complaints by model year

What owners report

While driving at highway speeds (approximately 70 MPH) with the vehicle's Assistive Driving functions engaged, the Driver Monitoring System (DMS) malfunctioned. Despite maintaining constant visual attention on the road ahead, the system issued repeated, erroneous audio warnings claiming driver inattention. I attempted to adjust my head and eye position to satisfy the sensors, but the system failed to register my compliance and continued to cycle through warnings. Consequently, the vehicle initiated an unwarranted "fail-safe" maneuver and suddenly applied the brakes while traveling in the flow of traffic. This uncommanded, rapid deceleration created an immediate and severe risk of a high-speed rear-end collision with following vehicles. The failure appears to be a false-positive defect in the eye-tracking software logic and its integration with the braking system. …

I am reporting a suspected safety defect involving inconsistent deceleration behavior in my 2026 Hyundai IONIQ 5. I regularly use Hyundai's i-PEDAL one-pedal-driving mode. In this mode, releasing the accelerator produces strong regenerative deceleration and can bring the vehicle to a stop. However, the vehicle does not retain this selected driving behavior after it is turned off and restarted. It reverts to a mode requiring substantially more use of the brake pedal. The behavior also changes in connection with shifting into reverse. In a Costco parking lot in [redacted], I stopped near the customer pickup area while using i-PEDAL. I briefly turned off the vehicle while a passenger loaded groceries. When I restarted and began moving, I expected the strong accelerator-release deceleration the vehicle had provided immediately before shutdown. …

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. …

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. …

The vehicle is less than 1 years old. Had 91% charge left. Turned in the car as usual. Turned in heated seats and heated steering wheel as the outside temp was 34 degrees. A pop noise occurred and my entire dashboard flashed like a Christmas tree saying electrical system failure. Pull over safety. The cars speed was reduced to 20 mph. This was extremely scary as this happened on a main road where the speed limit was 55. The ICCU failed according to the dealer. This has been a common issue among Ioniq5 cars and the manufacturer has failed to fixed this issue. This car presents a high failure rate of the ICCU computer that controls the entire car. Once this chip fails, the car can not be driven and it must be towed back to the dealership. This is not a one off. Hyundai also quietly remove the remote start feature to activate the heated seats. …

On March 22, 2025, our 2022 Hyundai Ioniq 5 suffered a sudden, complete loss of power while driving at night, after receiving Hyundai's recall service in January. While driving on city roads, the car displayed "Check Battery" errors despite the main EV battery showing ~75% charge. After stopping, we had AAA install a new 12V battery, which did not resolve the issue. Minutes later, while crossing a Y-shaped highway interchange, the car lost the ability to accelerate, leaving us stranded in a dangerous area. Hyundai Roadside Assistance gave an 89-minute ETA and failed to dispatch a tow capable of transporting our family of three. We were forced to call our insurance to tow the vehicle to safety. The car is now inoperable at a dealership. Hyundai has not followed up. This is a major safety concern - involving either the 12V system or software post-recall - and could impact other vehicles. …

When parking in a supermarket parking lot I slowly approached the space while braking. As I turned left into the space and released the brake pedal to allow the car to slowly roll into the space as I always do, the car surged as if someone floored the accelerator. I veered left to avoid a head on collision with the parked car facing me and went diagonally between the right front fender of that car and the left front fender of the car parked in the space to my left. I sideswiped both sides of my car and damaged the front fenders of both cars before I was able to apply the brake and bring the car to a stop. There was a mother with her two young children loading groceries into the car in front of me. Fortunately I avoided hitting anyone, but the witnessed the accident. I was in shock. My car suffered $25 in damages. …

Vehicle was involved in a double fatal. After viewing of dashcam video I suspect a malfunction of the vehicle may have occurred. The video appears to show the vehicle continuously accelerating despite the sound of what may be the driver attempting to repeatedly mash on the brakes. EDR records do not coincide with the dashcam video.