2025 HYUNDAI IONIQ 5 Complaints

With no warning lamps or lights, heard a pop, car stopped generating power, there was no place to pull over so we put on our hazards and kept driving. Car warning light on batter and it was telling us to stop driving as soon as possible, cars were honking and driving around us. We called AAA and they towed to the dealership we bought the car (it's a new car 8,000 miles). The ICCU failed, they replaced it. Reddit Ioniq5 owners report this problem is more frequent than other electric cars and that Hyundai has a recurring issue with this part.

On the afternoon of Saturday, December 12th 2025 I was preparing my car for a trip an hour north and back to drop my daughter off with her grandmother. I was charging my car with my Level 2 charger and preheating my car. Upon leaving for the trip, within a half mile I heard a loud popping sound coming from the rear of the vehicle and immediately had a warning on the vehicle stating "Stop Vehicle and Check Power Supply". The vehicle soon started to lose drive power, and I had to perform a U-turn and then parked at the nearby Quaill Volunteer Fire Department to perform a basic safety check. Knowing that I probably had the Hyundai Ioniq 5 ICCU issue, I knew that my car would soon have no power so I waited for an opportune time to leave the fire station to coast back to my house. After arriving home, I contacted Hyundai Roadside Assistance and my car was soon towed away. I was extremely fortunate to be so close to home when this happened - from what I know of the issue, had we been stranded on the highway with this issue we would likely not have been able to use the HVAC systems in the vehicle for long. At this point, the issue has been diagnosed at the dealership as an ICCU issue which is covered by warranty. I have not been told to modify anything about my charging amperage, and there has been no admission that the ICCU part itself is faulty (though I believe it must be - my vehicle has less than 8,000 miles and the previous model years of Ioniq 5 all had ICCU recalls already.)

I was driving with my family on 12/26/2025 and heard a very loud "pop" and then received a warning of "stop vehicle and check power supply." The car went into turtle mode and then stopped working entirely. It was a terrifying situation because there was no place to pull over immediately and the car was not operating. We were stranded as a storm was approaching, could not get a tow, etc. On 12/30/2025 the dealer told me I needed a new ICCU and fuse.

I leased a 2025 Hyundai Ioniq 5 (VIN: [XXX] ) on September 16, 2025 from Route 1 Hyundai in Monmouth Junction, New Jersey. Since I bought the vehicle, I have had to return it to the dealership a total of one time. My vehicle has been out of service for repairs since November 19, 2025 for a total of 35 calendar days. The current mileage on my vehicle is 3,026 miles. My vehicle has been in service at Route 1 Hyundai on the following days for repair of the following defects: Days: 11/19/2025 - present Defects: DTC P0AA700 Hybrid Battery Voltage Isolation Sensor Circuit fault This is a critical safety mechanism, and when this fault occurs, the high-voltage system will often shut down to prevent electrocution or further damage. DTC P1AA700 DTC P1AA700 on a Hyundai Ioniq indicates a serious issue with the high-voltage (HV) Battery System Assembly (BSA). I am having the following problems with my vehicle at this time: Unable to charge battery past ~30% INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

High voltage battery failure indicated by "check electrical system" error code and P1AD300 diagnostic code.

I was leaving from a friends' house and got a "Check electric vehicle system" error and the car went into "limp" mode while on the road. I drove to a hotel parking lot and dropped off my family then proceeded the next day to drive the car to a local dealership for service and the car maxed out at 12 mph before crawling to 1 mph while going up a hill before I could find a place on the side of the road to stop. While awaiting a tow truck the car's electrical system fully "died" leaving me stranded on the side of the road without even hazard lights to warn surrounding traffic. The problem has not yet been evaluated by a dealership, manufacturer or any other agencies. Several warning lamps and messages appeared, including the "Check electric vehicle system" error message.

Electrical failure while on the highway. Later diagnosed as failed ICCU issue that also destroyed the 12V battery. Very scary during rush hours traffic with passengers.

*I received a notification on my screen of the battery malfunctioning after only owning it for 3 1/2 months. *It was unsafe to drive because it was undependable. *I dropped it off at the dealership and was given a loaner a week lateronly after we insisted they owed us one. It has been over 6 months now and I still am driving a Kona loaner which is a downgrade. *No police or insurance reps involved. Consumer Affairs has little to no information. There wasn’t any prior indication before the notification on the screen.

What happened to me is a common problem with these models. I had an issue with the 12 V battery not being charged by the main battery as it should be. This led to a blowing of the main fuse which took out the ICCU unit. This seems to be fairly prevalent from what I can tell from online forums, and there needs to be a recall from Hyundai.

My car worked to get to an appointment on 22 Nov. It flashed an error 2 minutes into a 20 minute return trip, saying the cars propulsion failure was imminent. Vehicle would not turn back on after the 3 mile drive home. The ICCU failed. If this failed while driving, or while I was in a hot/cold location, my life and those around me would have been at risk. The dealer has been working with Hyundai America for a month to fix the vehicle, and so far has not been able to after trying 2x replacement parts.