2025 Hyundai Ioniq 5 Engine Problems

The diagnostic trouble code (DTC) P1A9096 in a Hyundai Ioniq 5 indicates a "DC/DC Converter Input Voltage Sensor Fault" within the Integrated Charging Control Unit (ICCU). No recall has been issued yet but this is a known problem.

I was driving on the CA 405 SB, Long Beach, at about 6 PM 9/19/25. All of a sudden this loud screeching noise started. It was so loud that I pulled off on the left shoulder instead of driving to the first exit. I assumed I was going to find something wrapped around an axle or wheel or dragging from the ground. There was nothing hanging from the car, so I got back onto the freeway and parking the car ASAP did a more thorough inspection of the car. I got on my hands and knees looked with a the flashlight And saw nothing. I got online and found Hyundai TSB 25-01-056H explaining that IONIQ 5 built between 12.03.24 - 3.25.25 are missing a wave washer that can cause the MGDU housing to make noise. And the MGDU needs to be replaced. I should take it to a dealer to get it fixed. I left a message with the service dept at Kearny Mesa Hyundai, where I'd leased the car on June 2, 2025. I left a VM with the Service Dept requesting an appointment and the screeching noise is my car. I made a number of recordings of the noise so I could easily provide it later. The noise stopped when I got off the freeway and hadnt started again. When I took it in on 9.22.25. They said I would have to leave the car for at least two weeks before they could look at it. They wouldn't provide a loaner because my car was built in APR/2025 after 3.25.25. The SA suggested I try another dealer for faster service. I took it to Pedder Hyundai on 9.24.25. They kept it all day and "verified the complaint." My window was not fully up. I told them that this is absurd. I was told the dealer needs to verify the noise to get it fixed under warranty. On 10.19 the noise started I made more recordings & drove it straight to the dealer. They couldnt get someone to go for a ride and had to get appnt and bring it back. I took it in on 10.21 while driving there, and the noise returned. I called the Serv Rep. He heard it clearly How can I send you the recordings of the noise?

Vehicle surges or accelerates at highway speeds of around 60-65 mph. Vehicle will not hold a consistent speed without a pulse or surge.

I have had my new car only two weeks and have driven only 500 miles. Yesterday, while driving on a freeway at constant 65 mph speed, I suddenly experienced COMPLETE POWER FAILURE. I coasted across three lanes of heavy traffic and came to a stop on the shoulder. There were no warning lights on the dashboard. I turned the car off, turned it on again, and the car drove normally. I checked on my Hyundai app and it said under Vehicle Health that all systems were normal. I called the Santa Monica Hyundai service center and was advised to drive home to Santa Barbara (on the freeway) and get in touch if the problem recurred. I drove my car some 50 miles to Santa Monica to be evaluated and the service rep said that all makes of EVs have this problem, not unusual. After some hours, I spoke to the shop foreman who said he had never seen this problem, that the diagnostics had shown no problem, that there was no indication that this had indeed happened, that he could do nothing further unless there was proof that I had experienced complete power failure, and that if it happened again I should obtain proof by videoing the dashboard and my foot pressing down on the accelerator without any response. I called the Oxnard Hyundai dealer where I had purchased the car and was advised to bring my car there for a second opinion. I drove the 60 miles to their service center. I was told by the service rep that he had never heard of this problem. I was given a loaner car to drive the 40 miles home and my Ioniq 5 was kept for evaluation. I discovered on Google that sudden power failures in Ioniq 5's are a known problem by both Hyundai and the NHTSA and that there have been recalls as a result. It seems reprehensible that Hyundai representatives in two different dealerships claimed that they had never heard of this phenomenon. I was at risk of a potentially deadly accident by losing power on a freeway. I am lucky to be alive.