2023 HYUNDAI IONIQ 5 Fuel/propulsion System Problems

INCIDENT DESCRIPTION: On November 24, 2025, while driving at ~60 mph on NYS Route 17 (highway) with ~15% battery charge, my 2023 Hyundai IONIQ 5 suddenly entered limp mode and lost motive power. The high-voltage battery state of charge dropped instantly from ~10-15% to 0%, triggering error code P1B9600 (HV battery cell imbalance—cells failing to charge/discharge properly). I was unable to fully remove the vehicle from the roadway. My elderly mother was a passenger; a passing tractor-trailer came within 1 ft of striking us when disabled. NY State Police responded (report available). Required $300 tow to the Hyundai dealer, stranding us 150 miles from home.//PRIOR RELATED FAILURES: 1. November 14, 2025: Stranded due to ICCU failure (recall 24V-868 related) (stranded on NYS State Route 444). 2. September 15, 2025: Same P1B9600 code/limp mode/power loss; stranded in the middle of active travel lane of NYS 444; NY State Police report filed. 3. August 2025: Initial HV battery-related sudden power loss; stranded on Interstate 90 Eastbound (Erie, PA area). Despite repairs (September 2025 ICCU/"limp mode" software updates; October 2025 ICCU/high-voltage fuse replacement under recall 24V-868), defects persist. The vehicle charge rate also appears low and the battery consumption rate seems high.// CURRENT STATUS: Dealer (Vision Hyundai) confirmed high-voltage battery pack defective, requiring full replacement. Vehicle purchased new October 2024, under warranty. In service since mid-November 2025 (>30 days downtime). Provided loaner now, but prior rentals unreimbursed.//SAFETY RISK: Repeated sudden power losses create extreme highway crash risk, especially with vulnerable passengers. I am a licensed professional mechanical engineer, and can provide technical logs, repair orders, police reports upon request.The issues I have experienced appear to be linked to ongoing ICCU/HV system issues in IONIQ 5. I respectfully request expansion of the recall investigation.

While driving on the freeway I heard a pop and a saw a warning notification on the dashboard to check the vehicles electrical system. This was followed by a warning that power was limited which resulted it the vehicle speed decreasing to 30mph, and finally a notice to stop the vehicle immediately. All of this occurred in about 5 minutes time. Thankfully, I was able to pull over to the side of the road without an accident. After this the vehicle became inoperable including hazard flashers. I had to wait on the side of the freeway for about an hour to get a tow. The vehicle was towed to a dealer which confirmed that the ICCU and high voltage fuse were faulty. My safety during this process was put at risk because A) during a snow storm I had to pull the vehicle over to the side quickly across 4 lanes of traffic and B) then remain parked on the shoulder with limited ability to notify other drivers that I was on the shoulder. The dealer has confirmed the failure, the vehicle is available for inspection, and the manufacturer has not inspected the component.

ICCU failure, confirmed by dealer. Vehicle was parked in garage connected to charger. The ICCU fuse blew, and the house breaker was tripped. The vehicle failure also ruined the Grizzl-E EVSE (charger).

Car won't charge on Level 1 charging; it popped the GFCI in my garage and now no longer charges on level 1 (regular slow AC charging).

The Integrated Charge Control Unit failed despite having all related recall repairs/actions implemented. Failure occurred while pulling into a parking place after completing level 2 charging to 80%. The failure has not yet been confirmed by the dealer, but all common symptoms match this failure including hearing a pop sound from the rear of the vehicle followed by “Check Electrical System” indication and limited distance low power, low speed mode. Had this happened while driving at highway speed, the sudden loss in power and speed could have been dangerous to respond to and get off the highway safely. The vehicle is scheduled to be inspected by the dealer shortly.

Vehicle warning alarm came on with message to immediately pull over and check power supply. Towed car to dealer where ICCU and fuse were replaced. This after 1-2 recalls were completed.

Was driving on highway and started receiving error messages for "check electrical system". Car speed dropped to max of 45mph while actively on a highway. Was able to pull off an exit but car needed a 55 mile tow to the closest dealer. Dealer has identified that the ICCU needs to be replaced but has no timeline as the item is on back order. Car is model year 2023, purchased in February of 2023 and has 22,000 miles on it.

This morning I heard a "pop" sound from the back of my 2023 Ioniq 5. A short while later a warning message appeared about the cars electrical system. A minute or two later a "Stop Vehicle and check power supply" message appeared. The infotainment screen said "A possible condition has occurred with your vehicle. A full system check is recommended TODAY." This is likely a malfunction of the ICCU. I have already taken this car in 2 or 3 times for recalls related to the ICCU, including one dealership visit within the last 30 days. As this is an electrical vehicle, electrical problems could leave me stranded. Without propulsion I would be at risk of getting hit on the highway. The same error message appeared at the service center. The car has been at the dealership all day, and I don't expect to get it back anytime soon. There was no warning of the failure before today.

The iccu failed causing the vehicle to suddenly go into limp mode

Was driving in Bellevue, WA leaving a parking lot. Heard a "pop" sound, and immediately had a "Check Electrical System" warning come up on the dash. From previous experience in 2024, was aware this requires immediate dealer inspection, so started driving to the dealer 6 miles away. After less than a mile, lost most power but was able to drive slowly into an office parking lot. Called Hyundai Roadside Assistance who sent a flat bed tow truck to transport the car to the dealer. ICCU was replaced in May 2024 after similar symptoms. The current ICCU (which is likely the failed component) was in service for less than a year.

These cars had an open campaign earlier in the year to check for faulty ICCUs. Mine was check in Jan and deemed to be good. In early Feb I was driving home alone late at night and suddenly I was unable to go faster than 20mph and in a matter of minutes the car shut off. It had to be towed and the dealer informed me the ICCU failed. It was very scary and extremely dangerous. This has been happening so often with the Ioniq 5's and there should be a mass recall.

After all of recall software updates were applied the ICCU still failed with no warning beforehand and resulted in power and propulsion failure.

On March 20, 2025, my 2023 Hyundai Ioniq 5 displayed the error "Stop check vehicle power supply" and abruptly shut down during rush-hour traffic, leaving my young son and me stranded on a heavily congested bridge. Immediately, the car’s display went dark, doors wouldn't unlock, and the gear shifter was immobilized. With no emergency functions available, we were completely trapped. On a slight incline, I had to continuously hold the brake pedal to prevent rolling forward into increasingly aggressive traffic, making an already frightening situation terrifying for my child. Police arrived but struggled to assist preventing the car from moving. After several tense minutes, the dashboard briefly flickered back on, enabling me to unlock the doors. AAA identified a dead 12V battery, replaced it at my expense, but the critical error persisted, causing another complete shutdown shortly thereafter. The vehicle was towed to Hyundai of Bedford, where technicians diagnosed the issue as a failed ICCU and fuse, parts that are now backordered due to high number of vehicals having this same issue. Alarmingly, Hyundai plans to replace these faulty parts with identical models, despite my vehicle having completed all recall updates. This means the dangerous malfunction could occur again without warning, posing ongoing severe safety risks to my child, myself and those around use. This deeply traumatic event exposed critical vulnerabilities in the Hyundai Ioniq 5, especially dangerous for families, elderly drivers, or anyone caught in similar emergencies. The absence of functional basic safety measures left my son and me unnecessarily vulnerable. My trust in this vehicle and any thing using the same ICCU is permanently broken. Hyundai urgently needs reliable, redundant safety systems to prevent such life-threatening scenarios. Until then, we cannot feel safe or secure in these vehicles.

I purchased this vehicle in 2023 I have had multiple problems with loss of power ICCU SOFTWARE UPDATES 2-3 per year. . Now my vehicle has been in the dealer for 31 days. Needs a new ICCU and Fuse. No parts no one will tell me when I will get my car fixed. There are 6 other Hyundai ionic 5 Cars sitting with no parts or repairs in sight. I want out of this vehicle it’s a Lemon Every time it has broken down I needed to call a tow truck. Can someone at NHTSA HELP ME? [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Upon attempting to merge onto a highway, the vehicle lost acceleration and a warning message appeared on the dash stating "Stop vehicle and check electrical system". Car speed was limited to 28 mph. I was able to exit and get the car to the dealership. This was on January 29th, 2025. Car was finally returned to me with a new ICCU on March 19th, 2025.

The first time the "aux" battery was not charging completely. 2nd time pretty much same issue, they claimed to have performed a software update, 3rd time warning lights came on "Problem, check electrical system" ..something like this. They told me to bring the vehicle to the dealership. After reading the problems stem from the ICCU, I decided to call them to ask if I should tow it in, due to all the warnings. After this we could not even get into the vehicle or drive it. Took us and the tow driver 4 attempts to get it out of the garage, down driveway and it had to be pulled onto the flat bed. They agreed and said that if there were any tow fees, they would pay them. Furthermore they said they would supply a vehicle to use while mine was being repaired. This was on Jan 25th, they still have not returned my vehicle, claiming they are waiting on parts, I've had to call them to check on it, this week NO contact what so ever.

Was driving the car and electrical system failure alert came on. Could not drive over 20 miles an hour on highway and then car just died once I got on side street

While running errands, my Ioniq 5 suddenly made a pop sound, and the dashboard displayed a “Check Electrical System” warning, followed by a loud alert and a message instructing me to “Stop Vehicle and Check Power Supply.” I was able to safely park in a lot and called for a tow. At that point, the car was still operable, but after being unloaded from the flatbed, it would no longer turn on. The issue was diagnosed as a failed ICCU, and I was informed it will take one month to receive the parts and complete the repair. Had this failure occurred on a highway or busy street, it could have been extremely dangerous. I am fortunate that it happened in a safe location.

On [XXX], I was pulling into my driveway when I heard a loud “clunk” and an error message came up on the dashboard saying “Check Electric Vehicle System.” I checked the 12V battery which was at 11.9 volts, so I first tried charging it with an external battery charger. However, the error message still came up, and when I tried driving on my street it was limited to 25 miles per hour, and eventually I got the error “Stop vehicle and check power supply” and the car slowed to a crawl. There was no warning prior to the failure. I had the latest ICCU software update recall performed at Capitol Hyundai in San Jose, CA on December 30, 2024. The next day, I had the car towed to Capitol Hyundai; a week later they diagnosed the problem as a blown fuse and ICCU failure. There is no estimate on when they will receive a new ICCU part to repair it. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While driving the vehicle on a local road at around 40 mph, check electrical system light came on and I heard a pop sound behind me. The vehicle would suddenly go no faster than 30 mph. Upon further driving, for additional quarter mile, it would drive no faster than 12 mph. I was able to very slowly drive it 1.5 mi back home. Once I arrive home, the vehicle was no longer operational. I confirmed that the 12-volt battery was at an extremely low charge and having the vehicle on would not charge the 12 volt battery. I believe the ICCU failed. I am waiting for Hyundai to further diagnose this.

June 2023 - 12 volt battery discharged overnight on consecutive nights. Dealer service eventually claimed that the problem was the navigation head unit was faulty and continued to draw current after the vehicle was turned off. The process took over 4 weeks to remedy since the necessary part was unavailable. January 2025 - While driving, a warning to stop the vehicle and check the power system appeared. After a few minutes the vehicle lost power and went into "limp home mode" which limits the vehicle to 25 mph. This problem was attributed to a failed ICCU. However, due to lack of availability the vehicle has been in the service department of the dealer for 3 weeks (Jan 17,2025 to Feb 4, 2025). The dealer estimates that it will be at least Feb 14, 2025 before the car can be repaired. While these two incidents may be unrelated, the result has been the same: the 12 volt battery does not stay charged up rendering the vehicle unusable. For drivers and passengers it is unsafe to operate the vehicle when speed is limited to 25 mph. I understand there is a recall on this part, but Hyundai's lack of support for providing replacement parts in a timely manner is causing owners of these vehicles to continue to drive them until the part actually fails which often happens at an inopportune time.

There is a known issue with the ICCU fuse. Mine blew this morning while driving and vehicle went into limp mode. Max speed is 20 mph and this is not safe on the highway. Vehicle completely died because the 12V can’t be charged with the blown fuse.

I was pulling into my driveway and I heard a "clunk" and then an error appeared on the dashboard saying "Check electric vehicle system." My 12V battery then died. After recharging the 12V battery with an external charger, the "Check electric vehicle system" message came up again when I started the car, and I could only drive a block or so before another message on the dashboard said "Stop vehicle and check power supply." I had the vehicle towed to a Hyundai dealer where it is waiting for them to diagnose the problem. I had all of the ICCU software update recalls performed on the vehicle before this latest problem occurred.

This car has had several recalls. On 12/9/24 I brought it to dealer re the ICCU update. Apparently what was done was just a software update. On 1/8/25 while driving 50 mph, the car suddenly lost power in traffic. Flat bedded to the dealer, they had to replace the ICCU. Todays Consumer Reports states that the ICCU recall was to replace the ICCU. Clearly the software update or check FAILED, putting me and other motorists at risk that night. I always thought a recall was a repair/replace situation, not an update/check situation. Being told by the service mgr that after all, it's a $3000 part, so if it's OK they don't just replace it. Huh? What? Not replacing it as a recalled problem is a problem. Their software update failed clearly, and now I'm afraid to use the car other than locally. The warning lamps came on only as soon as power was lost and slimply said "check electrical system". No warning BEFORE the event. I think the manufacturer's solution is a non solution, ineffective and dangerous to the motorists. In addition, I got the 4 or 5 recalls already on this car I've had for under 2 years now from my insurance company, not from Hyundai. What's with that? I would be happy to speak with someone about this. I've called the manufacturer and they read to me off of a script.

Charging port burned during DC fast charging session, resulting in melted charging pin. Unable to insert CCS connecter due to melted pin obstructing insertion. Further damage to electrical systems unknown. No warning signs shown aside from vehicle charging session ending. Lack of safety systems to prevent melting/burning of charging pins leaves potential for general vehicle fire, battery fire, etc. Dealer has had car in possession for over 10 days with no update. Corporate contact has been unresponsive.

I have had my 2023 Ioniq 5 for 13-months. I have had two safety recall services performed - I understand those were ICCU software related. On [XXX] my car sounded a sudden alarm and a warning appeared saying to "STOP and Check Power Supply." I was not able to immediately pull over but found the ability to pull over within about 1/4 mile, the vehicle seemed to be losing power. It was frightening as there were many pedestrians and cyclists and I had no idea what was happening. The car was towed through AAA - we had difficulty getting it onto the truck as there was very little power and almost no power steering. The vehicle is now at the Rowe Hyundai dealership in Westbrook, ME. I was told the ICCU would need to be replaced as well as some kind of fuse. I am not sure I will feel safe driving this vehicle even after it is repaired. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Latest recall had been applied, 2 weeks later a dead 12V. New one put in and 4 weeks later a pop and an immediate pull over vehicle charging system needs inspected. ICCU failure.

Vehicle's charging port appears to be overheating to the point that thermal throttling is occurring when attempting to charge. This issue first occurred in mid-May of 2024. Vehicle charged as normal before then. Vehicle was serviced by dealership for this issue on 05/29/2024. A software update was applied that did not solve the problem. In an attempt to find updates on this problem, I contacted Hyundai Customer Care by phone on 05/30/2024. Hyundai Customer Care agent read a scripted response that was first released to the public in 20203 and advised to wait for an unknown amount of time for an unknown fix which may or may not come to pass. Hyundai Customer Care had no updates more recent than the 2023 release from which the Customer Care agent read. This appears to be a known issue with no actual fix available to the customer and no ETA on when such a fix might be released.

First indication something was going awry was when attempting to charge the car. Heard normal click indicating charge had started, but no audible announcement that charging had started. Car started throwing "Check electrical system," then power plummeted and became unresponsive to accelerator, followed by "Stop car. Check electrical system," then finally something like, "Battery is being discharged by external devices."** Car had to be towed about 60 miles to nearest Hyundai EV service center. Eight days later, I got a call from service saying that the ICCU needs to be replaced. They will update me once ETA of part is known.

The vehicle made a loud popping noise and lost motive power. Dashboard lit up with battery symbol and said to check electric vehicle system. Dealer service is certain it is an ICCU failure. The vehicle had the software update to “fix” the ICCU issue thousands of miles ago.

The car loses power, slows down dramatically, and will not respond to the accelerator pedal. This failure has happened twice. The first time I was driving at about 40MPH on a side street when the car started slowing down with no warning and limped along at about 20MPH. I could not get it to move faster so I put my flashers on and made my way to the side of the street, pulled off of the road and shut the car off. When I restarted the car it drove normally. I reported the failure to Hyundai and they had never heard of this happening. They kept the car for 2 days and couldn't replicate the problem. That was about 2 months ago. Yesterday, 3/4/24, I was on the freeway going about 74MPH using the smart cruise control. I had just changed lanes when the car lost power and I got the message, "Smart cruise conditions not met." My speed dropped to the low 40's as other cars were whipping past me. Even though I floored the accelerator I got no response. I started the flashers, made my way to the right lane and got off on an exit ramp. I pulled off to the side of the ramp, parked the car and turned it off. Once again, when I restarted the car it performed normally. This is very dangerous! I could have easily been rear ended by another, faster car on the freeway since I slowed down so quickly without braking lights lighting. I brought it back to the dealer again today and they have kept it to run diagnostics. I don't expect that they will find any problem this time either.

The ICCU has failed after the recall repair was completed in September 2023. When the fuse pops the car indicates a check electric vehicle system message in the driver information screen.

This model has known issue. As I found after it occurred to my brand new IONIQ 5 . It has only 320mi. It had 87% battery and all of sudden it stop on road. No power on dashboard. After taking to service station they found “ "Inspected and found code P1A9096- DC/ DC converter input voltage sensor fail. Referenced campaign 997 for concern. With code present, per TSB, replace ICCU and fuse." This same issue I noticed in 2022 after reading forum. After putting my car in service station still I don’t have my car. It’s almost 17 days. If this car had recall I could have saved my time and unnecessary effort. Plus thank god it was local city read( school zone) if I was in highway and same thing happen to me it might be life threatening situations.

Car: 4 month old 2023 Ioniq 5, Starting on September 12, 2023 my car would not take any charge AT ALL, effectively make my car useless as I am down to 10 miles of range. For the next several days I tried multiple chargers at different locations trying both 350 kW and 7kW chargers. Other cars were able to charge their cars immediately after I moved from the charger. I have read that the software update I am going to get will reduce my charging capacity rate to fully charge slower. This car is not performing at the stats I chose it for. I will not be able to use this car if it cannot take fast charge for a full charge. I was not made aware of this issue that was well known to Hyundai (they have been dealing with this issue with its earlier Ioniq models) before going forward with this car. Nor would I have decided on this car if this issue was known to me.

Rear electric motor overheating on highway and motor shuts off only allowing front motor to work but acceleration is near nothing and is extremely dangerous. No codes or warnings pop up was told by friends with other ioniqs that it's a electric motor oil pump that malfunctions but hyundai refuses to solution ND realize that there is a problem with motor malfunction

While driving on the highway, after about 45 minutes, the electric vehicle goes into Turtle power-limited mode. The vehicle instantly reduces in speed from 70mph to as low as 35 - 45 mph. There are no warning lights or sounds. If you immediately stop the car and let it sit, it will work again temporarily but after 30 - 40 more min or less of driving, it will again go into turtle mode. Additionally, acceleration is non-existent when its power is limited, inhibiting the ability to safely drive as required to pull over or across intersections. This has been a constant event occurring multiple times and each time the vehicle has been on a freeway or highway. The dealer applied the repairs in the photo supplied, but they did not work.

Level 2 Charging intermittently shuts off or is throttled back to very low charging rates. THis results in car not being charged enough to be used. Hyundai advertises charging rates of 10 KW, but charging is either throttled back to 5 KG or shut when charging at 48 AMps. . Hyundai claims to know of this problem where some internal components of car overheat.

Vehicle is rated to charge at up to 48 amps. Charging at over 32 amps causes a failure due to overheating

When charging the car on an AC Level 2 charger, the vehicle overheats and charging fails. This is dangerous and can cause overheating/fire to electrical equipment as well as rendering the vehicle inoperable due to insufficient charge. There are no warnings ahead of time prior to failure. The problem is widespread and replicable, as evidenced by reports of forums, reddit, YouTube, and even a TSB issued by Hyundai that fails to adequately resolve the issue.

Cruise control became disabled and then unable to accelerate when pressing down on accelerator

When starting vehicle, presents a warning message in instrument panel of "Check electric vehicle system". The stated description indicates: "This warning message is displayed when there is a problem with the electric vehicle control system. Refrain from driving when the warning message is displayed." This could be an issue with the battery system, or steering system that puts others in danger due to the unpredictable nature of the error. The Hyundai app that reports vehicle statuses does not show any error or diagnostic codes.

2023 Hyundai Ioniq 5 (SEL, AWD) has bad ICCU (intergrated charging control unit). Will only charge at DC chargers reliably, level 2 or level 1 chargers will only work intermittently. Has been in the shop 2 weeks with no estimated repair date as the ICCU is on backorder. This issue is affecting a lot of Hyundai/KIA/Genesis customers who's vehicles share the same platform. The dealer won't even say where I am in line to receive the ICCU vs. everyone else in North America. This is really unacceptable for a car I paid almost $60,000 for.

We purchased our 2023 Ioniq5 approximately 7 months ago. We saw an article in the newspaper about the 2022 Ioniq losing power while driving. That has happened to us 3 times in the last several months so it is not strictly the 2022 model. One time was particularly scary as I was entering a busy freeway the car lost power and as much as I pushed on the pedal I could not go more than 20mph. This happened for about 15-30 seconds then finally accelerated. My husband said he has experienced the same problem with this vehicle on 3 different occasions. Thank you.

The charging system in the 2023 Ioniq 5 has multiple issues with connectivity and charging above a certain threshold. When charging at home using an electrician certified install by Merit and a county approved installation and Emporia EVSE 48A charger, the car prompts with a message that reads "Electric Vehicle Charge Alarm was processed. Your vehicle is not charging because of a connection failure. Possible reasons include: blackout, payment incompletion, charging stop button enabled." This has only recently started happening with the temperature in the closed garage reaching above 80F. The only way to rectify is to charge below 40A and this same issue is being reported by other Ioniq 5 owners via online forums as well. As it relates to DC fast charging at public infrastructure, the Ioniq 5 has a reliability problem with connectivity to the CCS1 ports that are used with Electrify America stations. The common denominator appears to be the charging port of the Ioniq 5.