2022 Hyundai Ioniq 5 Acceleration Problems

Owner reports

Selected complaints filed with NHTSA by 2022 Hyundai Ioniq 5 owners, lightly cleaned up (personal details are redacted by NHTSA).

I was coasting into a library parking space with my foot off the accelerator. The car accelerated even with my foot on the brake, jumped a curb and was stopped with above ground tree roots. The dashboard should have been lighted up with collision warning indicators and the automatic braking should have engaged. It did none of that. The car was totaled. Nothing was ever checked to see if it was a mechanical error. My insurer totaled the car.

I was driving 75mph on the freeway and I heard a pop and then the electrical warning system on the car lit up. I lost power to the car and was only able to accelerate minimally. There was a warning of low battery and the vehicle was going to lose power. I turned on my hazard lights and was able to get to the exit and was able to exit the freeway safely. Once the vehicle lost power I was unable to open the charger door, start the vehicle, use any of the key fob functions and had to jump the 12V battery, only to die immediately after. There is no pre-warning to this happening, it just shows the alert and the car loses all power. There are also problems with the vehicle after being plugged in to charge and it says "Charging Unsuccessful", or stops charging after a short period of time. It also will not charge to full capacity at home or the charging station. …

This report is an addendum to report 11762283 that was made yesterday. The vehicle allows driving with the rear liftgate ajar, however under some circumstances it engages the EPB when the vehicle comes to a stop while the gear state is still Drive. The gear state of the car remains in Drive when the EPB engages. This presents the driver with the choice, in the middle of the road and possibly in the middle of an intersection, of either exiting the vehicle and rearranging contents of the vehicle to allow the rear liftgate to close, or activating the accelerator to continue driving with the traction motor overpowering clamped EPB. Neither option is safe. I have attempted to reproduce this unsafe state of the vehicle and was successful in one case and unsuccessful in another. …

Was driving the vehicle in a local road and felt sudden drop in vehicle speed. Had to press hard the acceleration pedal to avoid any collision from behind. The vehicle could not gain enough speed in a ~45~60mile speed zone and driven ~2miles slowly to work place. The vehicle had to be towed to a local delearship as they suggested. The warning message was 'Stop vehicle and check Power supply' immediately after and changed to 'Check EV System' when started ~1hr later at the time of towing. The local dealership diagnosed it to be needing a new ICCU board, integrated charge control unit, which is in back order for ~2weeks (vehicle is still at dealership). In hindsight (after hearing recent news on ICCU failure of Ioniq5), the vehicle had a related issue in Feb 2023. …

The ioniq 5 has a one pedal driving mode, where the car will come to a complete stop without needing to press the brake pedal, similar to other EV's. In this mode, the gas pedal operates differently then in a conventional car - pressing the pedal approximately 1/3 of the way down represents neutral, where the car coasts. Pressing the pedal less then that - between 1/3 and not pressing it at all, applies braking power to the car, either through regenerative braking or the application of the physical brakes. The issue is, the brake lights on the rear of the vehicle do not light up when the gas pedal is depressed any amount. If you press the gas pedal as lightly as possible, the car will brake a fair amount but there is no warning to driver's behind that you are decelerating. I have twice been almost rear-ended, both times while slowing down in one pedal mode. …

After coming to a stop at a stop sign, and while the gear state was in Drive, the vehicle auto-applied the electronic parking brake because the tailgate was ajar. Gear state remained in Drive. Upon accelerator input, the parking brake did not release, and the vehicle delivered propulsion torque overcoming the parking brake. As a result, the vehicle accelerated and drove several blocks with the rear brakes fully clamped, which was only effectively indicated by a smell and smoke emitted from the rear wheel wells. An irritating repetitive audio and large flashing visual alert in the display cluster indicating the tailgate state distracted from any additional indications that may have been displayed. That distracting indication was continuously active from when gear state was first switched to Drive and did not correlate with EPB engagement.

When driving for a distance at higher speeds, power will suddenly drop to the zero point btw acceleration and regeneration. You can feel the car start to drag as the power drops. If you press hard on the accelerator to stop it from slowing, it will suddenly jump forward. This has happened now on several long trips where I am constatly fighting with the car to keep it powered and not slipping into the zero zone. When it leaps forward the lane assist will also grab control and make it difficult to control the car. The car also stops slowing consistently when I take my foot off the accelerator and will move/ jump forward more than is typical for an EV instead of slowing the way an EV should as it regenerates. This all happened twice previously on a long trip and today constantly during a three hour drive. Does not feel safe!

While driving, the 'check EV system' light comes on, intermittently what will happen is that when stopped the car will put itself in park, when it is in park I can not get it out of park, thus unable to move forward, it has also happened while reversing (and not stopped). I need to cycle the car on and off a bunch of times in order for it to finally turn back on. This is very dangerous while on the road stopped in a busy intersection and has potential for a crash. I have brought it to a dealer 4 times and they do not know what is wrong and cannot fix it. [redacted]

My vehicle was fully charged. About 1 mile after leaving my house, I received a warning message on my display (vehicle electrical system error or similar). Shortly after I received another message that power was reduced, then finally, "stop driving". I pulled into the nearest driveway and called roadside assistance. At that point, the vehicle was COMPLETELY dead. No lights or power whatsoever. I could not activate the car to shift into neutral. I had my vehicle towed to the dealership. They said it was due to a faulty ICCU and fuse. After about a week they were able to replace the ICCU, fuse and update the software.

Driving the car about at 45mph then I heard a pop sound from the rear of the car. Car displayed warning "Check Electrical Vehicle System." I pull over, shut it off, then restarted it. The "check Electrical Vehicle System" light stills on then an emergency message displayed 'Stop Vehicle and Check Power Supply.' When I tried to drive to a safe place I noticed the car would not drive faster than 25mph. If this would have happened in a highway this could have been a safety issue. Dealership confirmed that the Integrated Charge Circuit Unit (ICCU) needs to be replaced.

Acceleration complaints in other Ioniq 5 years