All symptoms of a 2nd iccu failure. Pop noise heard. Warning lights came on 12v drained, vehicle towed to nearest dealer.

Car indicated 12v battery was critically low and that I should stop safely. I was just starting it in a parking lot. This is a classic ICCU failure and the car is up to date on all recall updates. The car requires manual key unlocking for outside access at this point, and the rear hatch is only unlockable using the manual release mechanism which is recessed into the rear hatch and needs the key. The back two doors cannot be opened at all, from either direction and the handles don't work when the electrical system has failed and the child lock was engaged accidentally when it happened. This legitimately terrifies me for anyone traveling with back seat passengers who need quick exit. There isn't one.

My 2023 Ioniq 6 is not charging as it has for 3 years. When charging to 100% my app States 347 and 382 miles. It should be 361 as stated by Hyundai. What happens if I drive under 45 mph after 5 miles the miles goes down to 303. It is not working as stated. It is not holding miles properly.

The ICCU died a second time

The Integrated Charging Control Unit (ICCU) failed on my 2023 Hyundai Ioniq 5. The vehicle stopped charging prematurely overnight via AC Level 2 charging and then refused to charge again at all. The ICCU is responsible for maintaining the 12V battery by topping it up during normal operation. No warning or check engine light came on, I was only made aware when I attempted L2 charging and the car would refuse to take the charge. I understand that with a failed ICCU, if I'm unaware of the failure (e.g., relies solely on DC fast charging which bypasses the ICCU), the 12V battery can deplete without warning while the vehicle is in motion, potentially causing sudden loss of vehicle systems including power steering, brakes, and other safety-critical electronics. The vehicle was parked at the time charging failure was discovered. No injuries occurred.