2024 Hyundai Ioniq 5 transmission problems

Filed Aug 12, 2026 · Transmission · CA

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.

Filed Apr 22, 2026 · Electrical, Fuel system · CA

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.

Filed Mar 27, 2026 · Electrical, Transmission · GA

ICCU failure. Common problem but Hyundai seems to have no fix despite it happening for years now.

Filed Mar 20, 2026 · Electrical, Transmission · MD

Received multiple "Check Vehicle Electric Systems" on a drive which went away and then got into the car, turned it on, shifted into drive, and heard a pop from bellow before moving at all and the car went into Turtle Mode and blasted warnings. The car completely died with zero power leaving it stranded in sub freezing temperatures and unable to lock the car or open the lift gate to access the trunk area. Eventually it was towed to the dealership and was diagnosed to have a faulty ICCU which took 5 weeks to replace.

Filed Mar 18, 2026 · Electrical, Engine · VA

While driving I received the infamous "Stop vehicle and check power supply" warning, and it was then inoperable, needed a tow to the dealer for ICCU replacement. I can't believe you terminated your initial investigation into this in 2023 because they did a recall (which my car received). That recall did not fix the issue. It is March 2026 and Ioniq 5 and other models with the same electric system are dying on the road at the same rate as before. There is a large percentage of failed cars, and every failure is dangerous. This is a huge safety issue, and is not receiving adequate oversight by the federal safety agency.

Filed Mar 17, 2026 · Engine, Fuel system · ME

I was merging onto the highway. I got a warning that I needed to check my electrical system. I was able to back down the highway ramp and park on a side street. Within 20 minutes the car was fully dead and AAA needed to tow it to the dealer. The dealer confirmed that the ICCU needs a replacement. My family is lucky this happened in a place we could safely get to a side street. Had it happened 5 minutes later we would have been stranded on the highway with 2 small children.

Filed Mar 4, 2026 · Transmission · IL

According to Hyundai, all active recall campaigns have been addressed on this vehicle (the federal safety agency site says it wasn't, Hyundai claims it was on 9/22/2025). Last night (3/3/2026) while driving on an unlit, two-lane country road about 20 minutes from my house, I heard and felt a bang noise from underneath the rear cabin of the car accompanied by a message stating "Stop vehicle and check power supply" on the dash. The car immediately went into a limp mode, reducing speed to ~40mph. After about 0.5 miles, the car further reduced speed to about 25mph (in a 55mph zone). As speed reduced further (no indication of what the speed would be reduced to), I pulled the car off of the road and awaited tow service. As this happened in the evening on an unlit country road, I was forced to wait for assistance along a stretch of road that could have been hazardous. Hyundai's claimed recall campaign work was performed on 9/22/25 with subsequent recurring failure about 5 months later. The dealer cannot confirm the diagnosis or offer estimates of repair time/availability until they see the car (currently scheduled for next week).

Filed Feb 20, 2026 · Electrical, Engine · CA

The car stalled while being driven by my son. It displaced an error code. The Car had to be towed to dealership. It was diagnosed with ICCU unit failure. Needs to wait over a months for parts.

Filed Feb 20, 2026 · Fuel system, Transmission · CO

Vehicle displayed "Power limited" and slowed to a crawl, was able to drive less than a quarter mile to a safe place before it displayed "Stop vehicle and check power supply" then completely shut down. Diagnosed as ICCU failure by the Hyundai Dealer service technician, with the parts on backorder and no ETA for the 15 or so other Hyundai Ioniq 5's with the same failed ICCU waiting at the same dealership, in front of me.

Filed Feb 17, 2026 · Electrical, Engine · MO

ICCU failure: confirmed by dealership, submitting for your records - while driving the morning of 2/11/26 in Evansville, IN a warning message appeared on the dashboard stating 'Check Electric Vehicle System' followed by a rapid deceleration. Luckily there was not a vehicle behind me as they would have rear ended me. This failure occurred without warning and presented a significant safety hazard, leaving the vehicle stranded in traffic until I was able to restart it. Vehicle went in to turtle mode upon restart, would not go over 20mph at first then I stopped the car, restarted it again, it would move for 15-20 seconds before going in to turtle mode again and now it will not go over 10mph - interestingly, when I would stop and put it in reverse, the vehicle would move 10-20' and then come to a very abrupt stop as the entire vehicle shut off - had to tow the vehicle to the Hyundai dealership in Evansville Indiana where the ICCU was confirmed has having failed