248 of the
2,124 complaints filed about the Hyundai Ioniq 5
are about the transmission —
12% of everything owners reported.
The worst model year for it is 2022.
248
Complaints
12%
Share of all complaints
4
Crashes
1
Fires
Transmission & Drivetrain complaints by model year
Was driving to vegas, it was 103-107 degrees After fast DC charging drivetrain had issues that when pressing acceleration the car would have almost a loss in power that caused a stuttering movement. If forcefully driven, the error message drivetrain electrical system would pop up. Issue can be resolved but only after letting the car stay in park for 10-15 minutes after finished charging. Issue was repeatable but only if weather was hot enough. This shouldn't happen or at least warn the driver to not drive for a certain period instead of guessing the issue.
NHTSA complaint #11756391 — an unverified report by a vehicle owner.
I started the car and got the warning "check electric vehicle system." The car then lost power. It would only go 27mph with the accelerator pedal pushed all the way to the floor. My safety was at risk because my car was not responding appropriately to driver input. The car is at the dealership as it is undriveable in this condition. This is the second incident with this vehicle within 6 months.
NHTSA complaint #11756602 — an unverified report by a vehicle owner.
I was slowing down, actively pressing the brake pedal to bring the vehicle to a full stop. As the car decelerated to what my senses and perception registered as a full stop, I pressed the “P” (Park) button while keeping my foot on the brake pedal. I felt the physical click of the “P” button under my thumb while still holding the brake, and my mind registered that the vehicle had successfully transitioned into Park. Before turning around, I visually confirmed that the vehicle had come to a complete stop. Believing it was fully secured in Park, I turned my head to check on my child in the back seat and naturally released the brake pedal completely. However, the system had actually rejected my command. I assume that the vehicle likely still had a small amount of speed at the exact millisecond I pressed the button, and the computer automatically blocked the “Park” command and kept the car in gear. Because an electric vehicle operates in almost complete silence, with no engine noise or vibration to indicate that it is still in gear, there was no auditory or physical cue to alert me that the car was moving when I released the brake. While my attention was turned toward the back seat for a few seconds, the car quietly began to creep forward, leading directly to the collision with the car in front of me. Following the accident, I found that the vehicle produces slightly different sounds when Park is rejected and when it is successfully engaged. However, the owner’s manual describes only the dashboard message and does not describe these sounds or explain how to distinguish them, so their meanings may be learned only through the failure. At the time of the incident, I was not familiar with the distinction between these two sounds. Because my brain processed the physical press of the button as a successful action, and I had visually confirmed that we were not moving, my focus immediately shifted to my child. I was entirely misled by the digital interface.
NHTSA complaint #11749766 — an unverified report by a vehicle owner.
During a family road trip, my 2025 Hyundai Ioniq 5 (~9,000 miles, less than one year old) suddenly showed red "Check Electric Vehicle System" and 12V battery warning lights and then completely lost power. The 12V system failed entirely - the vehicle could not be driven or shifted, and the doors and the rear hatch could not be locked or unlocked. It had to be flat-bedded to a Hyundai dealer because it was completely inoperable. The dealer diagnosed a failed ICCU (Integrated Charging Control Unit) and a blown ICCU safety fuse (fault code P1A9096) and is replacing both under warranty; the component is available for inspection. The ICCU converts high-voltage battery power to charge the 12V system; when it fails, the vehicle loses all electrical power and drive capability. The warning lamps appeared immediately before total power loss, with no prior symptoms at the last scheduled service. This is a known, safety-critical failure on this platform: a sudden, complete loss of power can strand occupants and, if it occurs while driving, cause loss of motive power - a serious crash risk. My vehicle was stationary when it failed, but the same failure at speed would be extremely dangerous. I have video evidence of the car completely bricked out.
NHTSA complaint #11749425 — an unverified report by a vehicle owner.
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)
NHTSA complaint #11747025 — an unverified report by a vehicle owner.
Vehicle was parked in closed garage overnight. In the morning I tried to start the car and it was unresponsive. key fobs, digital keys, NFC cards none of them were able to open the car. Used a physical key to open the door, and then tried to turn the car on, nothing worked all screens remained black and car was unresponsive. AAA confirmed that the 12V battery was fully dead. When they jumped the vehicle we heard a pop in the car, which is a known ICCU failure indication. The car still turned on and was drivable. I got it to the dealership safely and they confirmed that the 12V battery was fully dead and car only turns in if jumped. They also confirmed that the ICCU had a failure as well and they are going to need to replace the entire battery pack/ICCU assembly.
NHTSA complaint #11741000 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11739646 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11734215 — an unverified report by a vehicle owner.
2022 Ioniq 5 SE. ICCU failed April 2026 with around 29325 miles. Original owner. Purchased June 2022. I had the original Recall 272 software update performed back in February 2025, but the hardware still failed a year later. **Timeline of Failure:** 1. **Phase 1 (The Trigger):** Level 2 charging stopped unexpectedly before reaching the limit. It tripped my house breaker and unfortunately killed my Level 2 EVSE (Grizzl-E) with a stuck relay. Didn't think too much of it because I had to be somewhere. Car started up normally and I was able to drive throughout the day with no problems. 2. **Phase 2 (The Warning):** The next day, I attempted Level 1 charging. It immediately tripped the breaker. I tried another outlet on a different breaker; the breaker didn't trip, but the car failed to initiate a charge after three attempts. 3. **Phase 3 (Dashboard Error):** After third failed attempt with the L1, I took a peek inside and saw the dashboard had a yellow triangle. With the charger still plugged in, I sat in the driver's seat and turned the car on. The **"Check EV System"** error appeared. I turned off the car and went inside to call the dealer. I called the dealer and they said I can have it towed there. They also scheduled an appointment for the next morning. I went back to car to attempt to position the car to make it easier for the tow truck, but the check ev error was not there when I turned on the car. It said ready and I was able to drive around the block a few times so I figured I'll just try to drive to the dealer. I drove the car to the dealer the next morning. It took **one week** to get my car back. **Diagnostics & Parts Replaced:** The dealer confirmed the following codes and performed a full hardware replacement: * **DTC P1E1300:** AC Power Module Failure * **DTC P1A9096:** DC/DC Converter Fault * **ICCU Part:** `36400-1XAA0-AQQH` * **HV Fuse:** `375F2-GI040-QQH` * **Coolant:** Install of Pink Antifreeze (`00232-19098`)
NHTSA complaint #11734110 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11733953 — an unverified report by a vehicle owner.
The car lost power while driving and an electrical warning was displayed on the screen. The issue was later diagnosed as a failure of the ICCU and blown fuse that had been previously recalled and replaced. Now it needs to be replaced again.
NHTSA complaint #11732961 — an unverified report by a vehicle owner.
As I began a drive cycle, I heard a pop sound and received the “check electric vehicle system” warning associated with ICCU failure. With ICCU failure, if I had continued to drive the 12V battery would have run to zero and the car would have died completely. Vehicle goes to dealer tomorrow for confirmation.
NHTSA complaint #11733152 — an unverified report by a vehicle owner.
Finished charge, low battery indicator on the dashboard. started to drive, within mile "pull over immediatedly" well documented and continued flaw with vechile ICCU component (that I had the software "patches" applied). Car will no longer accept charge (so now has the remaining charge before being a 3 ton brick) and cannot not be driven as if the 12v battery loses charge (which it will) I will lose powersteering and brakes.
NHTSA complaint #11732158 — an unverified report by a vehicle owner.
Car charged as scheduled overnight 3/28/26 but was dead the morning of 3/29/26 and when it was jumped gave error "Battery overheated, please stop and exit vehicle" and "check electrical system" - vehicle has been in shop for 16 days, no diagnosis except that it "probably" needs a HV battery.
NHTSA complaint #11731464 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11730155 — an unverified report by a vehicle owner.
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)
NHTSA complaint #11729574 — an unverified report by a vehicle owner.
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
NHTSA complaint #11729695 — an unverified report by a vehicle owner.
On April 1, 2026, my 2025 Hyundai IONIQ 5 experienced a cascading electrical failure. The vehicle first displayed a warning about a problem with the on-board charger, followed shortly by an alarm and the 'Stop Vehicle and Check Power Supply' warning with a red 12V battery indicator, rendering the vehicle unsafe to drive. Had I been on the freeway this would have been extremely dangerous. My Bluelink diagnostics history confirms three fault codes from that date: P1A9096 (ICCU fault, Electric Vehicle / Air Flap system, still Open as of 4/3/2026), and P056216 (Voltage Regulation fault, Hybrid Control system, reported twice), consistent with a cascading ICCU failure causing 12V system collapse.
NHTSA complaint #11729122 — an unverified report by a vehicle owner.