2025 Kia Carnival Hybrid Acceleration Problems

Mileage when the problem started

Owner reports

Selected complaints filed with NHTSA by 2025 Kia Carnival Hybrid owners, lightly cleaned up (personal details are redacted by NHTSA).

The contact owns a 2025 Kia Carnival Hybrid. The contact stated that while driving at undisclosed speeds, the vehicle hesitated before accelerating while depressing the accelerator pedal. There were no warning lights illuminated. The vehicle was taken to the dealer, who was able to duplicate the failure; however, the vehicle was not diagnosed, and the cause of the failure was not yet determined. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was opened. The failure mileage was approximately 3,000. The VIN was not available.

My wife and I have a 2025 Carnival SX Prestige Hybrid. We live in northern Maryland (lots of cold days lately!). This exact issue has happened three times and counting. While driving, our car will randomly lose all ability to accelerate. You can press the gas pedal all the way to the floor, and it will not gain speed. It seems to happen at lower speeds, around 30mph and it just caps off and will not accelerate and lose all power. The only thing that fixes the issue is literally pulling over and restarting the car, and then it drives fine. We took it into the dealer after the second incident and they claimed that a camera was just obstructed by ice, so the car probably thought it detected something in front of us so it stopped accelerating as a safety feature. …

I live in [redacted]. On the way to [redacted], out of no where the car stopped accelerating. Was in eco mode at the time and dropped completely while trying to accelerate in the middle of the road. Pulled over completely turned off the car checked the engine nothing seemed out of the ordinary. Ran the diagnostics from the car and didn't show any errors. Turned off again for a bit and turn on and everything was fine. Moved from eco to smart and turned around worked fine for about 5 m so we thought everything was on and tried to go back north to finish our trip and while on smart mode started to accelerate again and didn't want to accelerate. Turned around and decided best to take it to dealership Monday. We have about another 1 hour to 2 hours to get home and it's working fine in smart mode but it shouldn't randomly drop acceleration at all in the middle of driving. …

On five separate occasions, while turning onto a high-speed roadway and attempting to accelerate to the flow of traffic, the vehicle suddenly lost the ability to accelerate. Despite pressing the accelerator, the vehicle would not exceed approximately 35 mph and then began to decelerate. During both incidents, a "Check Hybrid System" warning appeared, and I was forced to quickly pull over to the side of the high-speed road. The vehicle would only return to normal operation after it was turned off and restarted. This loss of power while merging into traffic created an extremely dangerous situation. Having three young children in the vehicle made the experience especially frightening, and I no longer have confidence that the vehicle can be relied upon to operate safely. …

When driving my van to work in the morning, I would get an alert on my screen that says to check the driver assistance system. Then I turned on to the freeway on ramp and my car lost all power, not letting me drive faster than 30 mph. I was able to get off of the freeway and on to a side street when another alert, accompanied by loud beeps, came on saying "Check Hybrid System. Stop safely." I was able to pull to the side of the road and turn the car off. When I turned it back on it seemed everything was fine. I took it to the dealership and they couldn't replicate the problems and the car didn't register any errors. So they returned it to me. This morning I drove to work and the exact same thing happened at the exact same place. Only this time I wasn't able to get over as quickly and my car shut down in the middle of an intersection. Luckily I was able to coast to the side of the road. …

Today I had an issue with my 2025 Kia Carnival Hybrid SX Prestige where it would not allow me to accelerate past 31 mph. I was on an on-ramp to the highway with my baby in the car and I was flooring the gas, yet it still would not go past 31 mph. I put on my hazards and pulled off, and checked that the max speed setting was not on. I even tried setting the max speed to something higher like 50 mph, and the screen confirmed this, but the car still did not go past 31 mph. Luckily I figured out that cruise control still works past this speed limit, but it was super dangerous getting onto the highway going 25 mph slower than everyone else. When I eventually got to a red light I turned the car off and on and that seemed to solve it, as I was able to go past 31 mph. Later that day on a different drive, this exact issue happened again where I could not accelerate past 31 mph. …

This complaint is a follow up to complaint #[redacted]. I took the car in to Dennis Eakin Kia in [redacted] to repair what caused the car to go into Limp Mode after slamming on the brakes. The dealership did a deep scan of the hybrid control and power train control module for historical or iintermittent codes. They could find none because the car apparently does not save them after the ignition is turned off. They are trashed. They also tried 4 times to re-create the event by slamming on the brakes, but were unable to re create it. They returned the car to me without fixing it. This is another deep -imbedded safety hazard of this car that a well-documented safety hazard from many drivers cannot be fixed because the car trashes any evidence of these incidences. …

Within 5 minutes of driving, the car stopped accelerating. Check hybrid system alert appeared one minute later. Car stalled out within approximately 1-2 minutes after warning light appeared. No other warning lights were present prior. This is a 2025 new Kia Carnival Hybrid. I was stranded on the side of a 55mph road. The first time the police helped me roll it off the road. The second time it couldn't be pushed even though it appeared to be in neutral. The car dies but the accessory functions will not turn off. We have to unplug the battery each time. This car could die ANYWHERE leaving you stranded in a very dangerous situation. There is very little warning. This is extremely hazardous. This is the SECOND time this has occurred with a combined total of 5 hours waiting for tow trucks and countless hours contacting Kia. Kia kept the car for two weeks and recharged the battery. That's it. …

My carnival is only a few weeks old. The first week of driving I was on the freeway and I was suddenly unable to accelerate. The started slowing down and pressing the gas did nothing. I was able to get off to the side of the freeway where I turned off the car. Once the car was back on it was fine. However later in the drive while street driving the same thing happened and I again had to pull over and turn off then on the car again. I explained this to the dealership on the phone thinking it may be an issue with the mode I was driving in. The dealer told me he had heard of this before and I need to switch modes. I have since switched to smart mode where it goes in and out from economy to sport and it failed to accelerate again twice this weekend where I had to pull over and turn off the car. …

Van accelerates up to 31mph only. Top speed is 31mph even with accelerator/gas pedal completely pressed to the ground (RPMs increase to 4K with no acceleration.) No warning or display lights illuminated. This happens in cold weather (under 20 degrees F), first trip after sitting overnight or for a longer period of time. If I pull over and shut off/restart the car, it resolves. However this has happened in stretches of road with limits 55+, little/no shoulder and approaching cars and it's a safety hazard to 1) not be able to speed up and 2) not ideal to pull over to turn off/on car especially with children in the car. Van was inspected by Kia Dealer and found no issue/was able to recreate at the auto shop so it was given back to me. First instance happened at 1,500 miles and is continuing. I do have video of this instances happening.

Acceleration complaints in other Carnival Hybrid years