2026 Hyundai Ioniq 9

The vehicle was plugged in overnight. To the set 80% limit. When I got up to leave for work and take family out. The vehicle check electrical system warning ⚠️ came on and the then the vehicle would not drive past 41mph. Then in a few minutes dropped down to 28mph and would not go any further. Took the car to dealership which was miles away and 18 miles per hour was my top speed when I pulled in to the dealership lot. This was one day after I had dropped the car off for a route 7K mile tire rotation and filter change. They claimed they topped off fluids. I keep reading that the ICCU is failing on the Ioniqs and this symptoms seem to match. I am now waiting on diagnosis to be done Tuesday or Wednesday this week of the 5th.

While driving on the freeway utilizing Highway Drive Assist, I suddenly received a warning on the heads up display stating that assisted systems were unavailable, at which point the Adaptive Cruise Control & Lake Keep Assist both deactivated. I pressed the button on the steering wheel to reactive the system and received "conditions not met" error. At this point, I placed my foot on the accelerator and it was completely unresponsive. I stabbed at hte accelerator as well as held it down without issue. Regenerative breaking also did not reactive. Fortunately, I had enough momentum to change lanes safely to the shoulder and power cycle the car. I took the car to my local dealership who did a brief test drive and could not recreate, returning the car to me without contacting Hyundai proper, and recommending I call them directly myself.

Occasionally while driving my IONIQ 9 in sunny conditions with glasses on while utilizing Lane Keep Assist and the Adaptive Cruise Control system the car flashes a Warning about keeping your attention on the road, and then continues on beeping and chiming before ultimately completely stopping in the middle of the road unless you disengage the Lane Keeping Assist and Adaptive Cruise Control. I believe the sensors on top of the Steering Wheel aren’t calibrated that great for people who wear glasses, as this issue does not occur when I take my glasses off. I am not in any way obstructing the sensors, and in all cases when this has occurred, my attention is on driving and the fact that the vehicle begins to decelerate into a complete stop while in the middle of traffic is terrifying. This has happened to me about 3 times now since getting the car and all 3 times it was while I was wearing my regular glasses. When I have my sunglasses on I haven’t experienced the issue.

My ICCU failed, which caused a fuse to blow and some electrical wiring in the car to melt. This caused the car to completely deplete the 12V battery, which left the car completely inoperable. The vehicle was towed to a Hyundai dealership, where they ordered the relevant parts and changed them under warranty. I was without the car for roughly two weeks.