2025 KIA CARNIVAL HYBRID Complaints

On a day which had a high temperature of 16F our Kia Carnival Hybrid SXP, after not being used most of the day, when driving would not exceed 31 miles per hour. The engine would not rev loudly or give any indication of an error but would not go over 31 mph even with the gas pedal fully depressed. After pulling over and turning the car off and on the problem did not repeat.

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. I am taking my car to Kia in a few days to get it checked out. There was no warning messages and the screen's max speed did not match with what the car was actually doing.

The following has happened 4-5 times now on our Kia Carnival 2025 SXP Hybrid: After turning on the car, the car can be driven but does not allow the driver to increase the speed beyond ~30 miles per hour. No warning indicators or messages are displayed when this occurs. Turning the vehicle off and then on again temporarily resolves the issue. One of the times it occurred, I went straight from a 25 mph city street onto a highway onramp that didn't have a safe place to pull off. When I got on the onramp, I discovered that the issue was happening as I was unable to accelerate beyond 30mph. The highway had a speed limit of 65mph and a minimum speed limit of 55mph. Joining the highway at 30mph was both illegal and unsafe and could have absolutely caused a fatal crash. ---- To troubleshoot this issue, we took it into the dealership and they didn't find any errors recorded or anything abnormal in diagnostics. They told us it was probably just a malfunctioning of the "Auto Highway Speed Change" setting that is intended to slow you down around curves when using cruise control on the highway. We told them that didn't make sense because it happened to us on city streets where that setting isn't even in play, but they insisted it was still the culprit and didn't investigate further. It happened again to us today with AHSC disabled, so clearly the AHSC setting doesn't explain things(and would be an issue that needs fixing even if it did).

I was driving on a secondary road that has a 45 MPH speed limit when the vehicle decelerated to 31 MPH on its own. I could not make it go faster with any application of the accelerator. This lasted for about 5 minutes. I called the dealer service and they said it was probably a "glitch" and they could not investigate unless I left the vehicle with them until they could reproduce it. One unusual fact is that it was very cold the morning it happened, 9 degrees fahrenheit. I believe this could be very dangerous, particularly if hit happens on a highway. I spoke to another owner on Reddit who had the same thing happen twice.

The vehicle(2025 Kia Carnival HEV) is brand new, just over one month old. We parked it in the garage, and after just 4 days of not driving, the battery was totally dead. We were not able to start the van. The battery was 4.5v when measured with a digital volt meter.

Being a new vehicle the 2nd row seats do not easily slide forward and back. My wife was attempting to move the 2nd row seat forward using the mechanism on the outside of the seat. The back of the seat and the seat moved forward suddenly, striking her in the forehead. The mechanism that holds the 2nd row seat belt is made of a very hard plastic. This hard plastic is what made contact with my wife's forehead, knocked her glasses off and left a swollen lump. The seat belt mechanism and/or plastic material needs to be re-engineered. This could result in a serious injury to a young child or elderly person.

The vehicle is brand new. We drove it home from the dealership and parked it in the garage, and after just a few days, the battery was totally dead and unresponsive.