2023 Hyundai Ioniq 5 transmission problems

Filed Jun 28, 2026 · Electrical, Transmission · VA

I have a 2023 Hyundai Ioniq 5 Limited and had the ICCU "popped" (failed) which took about two weeks to replace. This time we were lucky that in happened at our home but had we been driving the car would it would have completed died. We regularly drive from from [XXX] to [XXX] were there are large section of [XXX] with no cell service. Meaning potentially walking for miles in extreme heat or cold. Hyundai right now seems only interested in continuously replacing the part rather than actually fixing the route cause, making it so the car is not trustworthy or safe to drive long distances. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed May 22, 2026 · Electrical, Fuel system · WA

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.

Filed May 17, 2026 · Electrical, Transmission · PA

The ICCU died a second time

Filed Apr 28, 2026 · Electrical, Transmission · NJ

ICCU failed at 20,000 miles, 2 years after I first got the vehicle. Blue link showed the P1a9096 ICCU code failure. Car could not be driven for more than a few minutes then the message to stop safely came about and car would die. It took the dealer 2 months to replace the ICCU with the SAME defective part. It is only a matter of time before it fails again.

Filed Apr 27, 2026 · Electrical, Transmission · NC

My Hyundai IONIQ 5 has repeatedly lost 12V power and shut down. The vehicle had to be jumped by AAA multiple times. After being restarted, it died again, and after two days of use it was dead again. I am concerned this is related to the known ICCU / 12V battery charging issue affecting IONIQ 5 vehicles, which can cause loss of motive power or make the vehicle undrivable. The vehicle is currently at Hyundai Southern States in Raleigh, NC for diagnosis and repair.

Filed Apr 9, 2026 · Electrical, Transmission · AZ

There was sudden power reduced and turn to the limp mode(Turtle symbol popped up). After pull over my vehicle to highway shoulder, the vehicle became total power loss. Unable to drive anywhere. It was a dangerous situation for my family. We waited tow car and took my vehicle to Hyundai dealership which located close to my house. They diagnosed my car and after a day. They told me it needs to be replaced a ICCU assembly and Fuse. There was no ETA for the parts. They provided me a loaner’s car. After about 15 days, they fixed and I was able to take my car.

Filed Apr 7, 2026 · Electrical, Fuel system · MT · crash · 1 injury

7 incidents of electrical drive problem incidents 1-3car would not start despite full battery Incident 4 same thing and car went to dealer, they said know problem and they would fix it overnight by downloading new software and charge about $400 for new 12V battery Incident 5 While on freeway using cruise control card speed varied wildly I disabled cruise control and with manual throttle same problem Incident. 6 In middle of traffic car went blank no lights or anything. I tried to restart 3 times and nothing, so I sat back and was in process of calling for tow. I did nothing and car violently accelerated and turned into steel pole. Only injury I had was bump on head that went away. As soon as the ghost mode engaged I hit the brake which likely prevented more damage to me, but front end of car was damage Incident 7 While I was detained someone else drove car to dealer and driver reported felt like driving on ice with rapid direction and speed changes Currently at dealer where neither dealer or Hyundai will take of problem and I get run arround from Hyundai and dealer. Dealer claim the don’t know is the problem. Dealer has had car for approximately 65 days Bottom line, the car is totally unsafe to drive and very dangerous

Filed Apr 7, 2026 · Electrical, Fuel system · CA

On 11/7/25 , we were driving my 2023 Hyundai Ioniq 5 to a friend's home in rural [XXX] , a trip of approximately 160 miles. At around 5:00 PM, we stopped about halfway to our destination to charge the battery. The car would not charge above 47%. While we continued to attempt to charge the battery, the console displayed a Check Electrical System Warning message, and we received the DTC P1AA700 via BlueLink. We were concerned about our safety on the drive up to the mountains. We were afraid the car would stop running on the highway and cause an accident. We were also concerned the car would die in a remote area and we would be stranded. However, the dealership was closed for the weekend. We drove carefully to our friend's home. I contacted Stevens Creek Hyundai on 11/10/25 and arranged to bring the car in on 11/11/25. It had 13,652 miles on it at that time. Eventually, the dealer confirmed the DTC P1AA700 and said they would need to order a new EGMP battery. The car was in the shop for 128 days, waiting for Hyundai to "build a battery" in [XXX] . Eventually, Stevens Creek Hyundai replaced the EV battery and I picked up the car. Given the delay in repairing my car and the growing evidence of Hyundai battery failures, we wanted to report this problem to the authorities. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 5, 2026 · Electrical, Transmission · GA

While driving the vehicle, the ICCU failed. The vehicle shut down in the middle of traffic without any warnings.

Filed Mar 20, 2026 · Electrical, Transmission · ME

ICCU failure, left stranded for a tow