2025 Hyundai Ioniq 5 acceleration problems

Filed Sep 4, 2026 · Acceleration, Fuel system · NY

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...

Filed Sep 2, 2026 · Acceleration, Electrical · VA

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.

Filed Jul 7, 2026 · Acceleration, Brakes · CA

1. Sudden Unintended Acceleration On two (2) separate occasions, after coming to a complete stop at a red light with foot on the brake pedal, the vehicle suddenly lurched forward on its own. 2. Brake Pedal Malfunction On more than ten (10) occasions, when attempting to stop at a light, the brake pedal briefly behaves like the accelerator for approximately 1–2 seconds. Driver has to release the brake and press it again to restore normal braking function. 3. Doors Unlocking/Opening on Their Own On more than one hundred (100) occasions, approximately 10 minutes after parking — with no key fob or phone nearby — a door opens on its own. Confirmed via mobile app notification and visual confirmation from a distance each time. 4. Apple CarPlay Connectivity Issues CarPlay frequently fails to connect. During phone calls specifically, the connection drops in and out intermittently. 5. Sticky Residue on Door Handles A sticky, adhesive-like residue is present on the interior passenger door grab handle and rear door handles. Residue does not clean off and transfers to hands on every use.

Filed Jul 7, 2026 · Acceleration, Brakes · CA

1. Sudden Unintended Acceleration On two (2) separate occasions, after coming to a complete stop at a red light with foot on the brake pedal, the vehicle suddenly lurched forward on its own. 2. Brake Pedal Malfunction On more than ten (10) occasions, when attempting to stop at a light, the brake pedal briefly behaves like the accelerator for approximately 1–2 seconds. Driver has to release the brake and press it again to restore normal braking function. 3. Doors Unlocking/Opening on Their Own On more than one hundred (100) occasions, approximately 10 minutes after parking — with no key fob or phone nearby — a door opens on its own. Confirmed via mobile app notification and visual confirmation from a distance each time. 4. Apple CarPlay Connectivity Issues CarPlay frequently fails to connect. During phone calls specifically, the connection drops in and out intermittently. 5. Sticky Residue on Door Handles A sticky, adhesive-like residue is present on the interior passenger door grab handle and rear door handles. Residue does not clean off and transfers to hands on every use.

Filed May 23, 2026 · Acceleration, Electrical · TX

I was driving on a busy highway at a high but legal speed. For a few seconds the vehicle appeared to reset. I lost control and the screen went blank. It was a miracle I did not hit another vehicle. I contacted the dealer and they stated unless it was happening frequently - there is nothing they could do. I spent hours on the phone with the dealer attempting to schedule an appointment, they stated their EV person was not available. I contacted Hyundai customer service. They ignored me for months. They assigned me a contact person - but she would never return my calls. I called the main support number and started over after several months. This representative collected all my info - title, purchase receipt, etc - but then closed my case after a couple calls. They totally ignored the concern.

Filed Apr 16, 2026 · Acceleration, Fuel system · WA

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.

Filed Mar 20, 2026 · Acceleration, Electrical · NJ

ICCU unit of the car short circuited right in middle of driving and caused the car to go in "limp mode". Sudden pop noise and slowdown created situation where car could be rear-ended. The part has already caused recall for prior model years, but model year for my car is not included in the recall. Based on internet search it is a continued and widely prevalent issue, manufacture has not done enough to fix this and a recall needs to add new model years. Additionally, the parts are backordered and there is no immediate fix.

Filed Feb 28, 2026 · Acceleration, Electrical · PA

On [XXX] while driving the car on a city street in Northhampton, MA, I heard a loud "pop" and there were multiple warning lights, beeps and messages indicating there was a problem with the electrical system. The car slowed dramatically and I was unable to drive at a safe speed to keep up with traffic. The car slowly lost power and I was able to pull over to the side of the road. The temperature was 15 degrees F - very cold, no heat and I had to stay with the car in freezing cold temperatures to await transport via tow to the local dealer. The tow service required that someone be with the vehicle in order to receive a tow. The dealer diagnosed the car with a failed ICCU - a well-known, increasingly common issue with these cars - and said there were already 10 Ioniqs on the lot awaiting replacement ICCUs. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 23, 2026 · Acceleration, Driver assistance · FL

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.

Filed Feb 9, 2026 · Acceleration, Electrical · CO

My new 2025 Ioniq 5 that has 8,700 miles on it suddenly popped up the message "check electric vehicle system" warning as we were driving in our neighborhood. My husband then realized that he could not drive over 30 mph just as he was merging onto our local Highway in a 65 mph zone. We limped along until the next turnoff and turned around. We decided to take the chance to get back onto the highway for a the short distance back to our house at 30 mph and returned the car to the garage. It was towed this morning to the dealership and declared to have a failed ICCU unit. All parts are back ordered indefinitely.