There are 5 owner-reported powertrain & transmission complaints for the 2024 Hyundai Ioniq 6in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
ICCU failed. The car suddenly decelerated from 40mph to 25mph or less with no warning. The ICCU is confirmed to be an issue for Hyundai. I had the software update to fix the problem in 2025. It is currently at the dealership in Fort Mill, SC. DTC error code shows it as an ICCU failure. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There were no warning lamps to until the failure occurred.
I was driving on the highway, 65mph when I had a sudden loss of power, check electrical system warning and a battery picture came on. I was reduced to approx 10mph suddenly in rush hour traffic, in the left lane, with no shoulder to pull over to. I was able, with the kindness of other drivers slowing down, able to move to the right lane, then to the shoulder. Called AAA for tow to dealership. 12v battery and ICCU damage.
The morning after a successful level 2 charge (from 35% to 80%), the ICCU fuse blew, resulting in no power to the car. I had to have it towed to have it fixed (both the fuse and ICCU were replaced under warranty). The car had 20,013 miles when the fuse blew and I had both safety recalls (software updates) addressed when they came out. I thought the updates were to prevent this from happening. Fortunately I was in my garage and not on the road; however, just the evening before, I was on I-95 for over an hour and glad it did not occur then. So now I'm fearful that it could happen again when far from home.
When driving recently, the car suddenly began showing a warning message “check electrical system” and would not go beyond 25mph. I was on the way home but still far, and had to turn on my hazard lights to alert other drivers. Eventually the car escalated the warning to “pull the vehicle over” and implied that the main battery was having an issue. I had to have th car towed to a dealer (closest is 10 miles) who eventually diagnosed the issue as a blown ICCU. My understanding is this is a critical component to the charging infrastructure and must be fully operational for the car to safely drive. Hyundai repaired the part and I had the car back in a few days, but I could get no assurances on what happened or whether or not it would occur again. The car has 14,000 Miles in the Washington DC area. It seems incredibly unsafe that this component could blow at any time. I also understand there are many other owners with this exact issue.
ICCU failure DTC P1A9096 12 volt battery depleted charge and would not charge off of traction battery shutting down all systems. Vehicle stopped on the middle of highway creating a safety issue. Vehicle was in previously and had all recalls performed related this possible issue. Vehicle has been at dealers without a resolution for weeks.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on May 4, 2026