2025 Kia Carnival

We have been having persistent safety issues with this vehicle. The issues have ranged from unsecured gas cap to loss of power. We’ve also had severe transmission issues where the car will not shift out of first gear. This happened on the Garden State Parkway and nearly caused an accident as the car wasn’t able to go above 27 mph safely.

For the third time the 2025 KIA Carnival Prestige I own lost power while driving on the interstate! Without warning, the vehicle would no longer respond to the accelerator pedal. No matter what I did I could not get the vehicle to accelerate past 35 mph. The minimum speed limit on the interstate is 45 mph. I had to immediately engage my hazard lights and make my way over to the shoulder of the road from the passing lane. This was a dangerous situation for me and my family and others on the highway. Warning lights came on, check engine light, charging system, and a maintenance service message. Driving in Sport mode, Smart mode, nor Econo mode could change the negative situation. This took place multiple times during the final leg of my last trip to [XXX] , extending for over 120 miles. This is a very unsafe, unreliable vehicle, that should never be driven on public roadways… especially not highways nor interstates. Three negatively, traumatic experiences is ENOUGH!!! I’m DONE!!!! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Carnival was working fine then, without warning, I was unable to accelerate. Had entered highway and reached a maximum speed around 30 mph in a 55 mph zone. Pedal fully depressed and zero acceleration, dashboard read "check hybrid system, stop safely". Tried changing driving modes to no effect. Lots of cars speeding past as I pulled to the side to restart the vehicle, then it worked again without issue. Happened one other time, similar circumstances and results.

I was on the on-ramp getting on the highway and whenever I started to increase speed and try to get over into the next lane, I noticed the car all of a sudden jumped a little bit and then it started consistently jumping in the check engine light was flashing, and I couldn’t keep the car over what ended up being 50 mph anytime I tried to go over 50 mph. The car jumped in was shaking pretty pretty aggressively I was able to finally make it to a gas station at the very next highway stop and after I shut the car off and turn it back on it seems like it was OK, but I’m still very scared to drive it. I then took it to the dealership to have them check for any store or pending codes because after we had stopped and turned the car back on it no longer had the check engine light on, and the dealership was not able to locate any stored codes in the system to see what it happened nor were they able to replicate the issue that we had found. Is a rec out on my vehicle, but no remedy is available and notices will not be sent for another month and a half at this point I am extremely uncomfortable driving my vehicle as I have young children and anything with a fire hazard is not safe.

TL;DR : Vehicle engages limp home mode without any notification to the driver that it is in limp home mode and doesn’t generate any codes for technicians to identify why the vehicle went into limp home mode. During oil changes, a significant amount of residual oil remains in the engine. When the lube tech fills the oil using the recommended amount, engine is actually over full of oil as indicated on the dip stick. The vehile will start and run fine for a while. Later however, an oil pressure sensor will detect the over full status and put the car into limp home mode. No check engine light, no oil light, no indicator saying it’s in limp home mode, and when the service tech investigates, no code thrown for the issue. A manual checking of the dip stick will reveal the oil is over full. The fix is to drain oil to normal levels as shown on the dipstick. It isn’t a defect considering that it’s reasonable to expect a vehicle to be operated with the correct amount of oil. A future software update for the oil sensor to throw a code for the tech would be appropriate.

I live in Alabama. Temperature here is 34 degrees so far in the morning. My check engine light is on. I have taken it in and had diagnostics and they can't find a code or code history. My heat and AC do not work properly if the ambient temperature on the cluster doesn't show up or is not correct. 72 degrees when it's not working right will run you out of the car it's so hot. The cluster currently says it's -15 degrees outside and has the snowflake beside it. I am scheduled bc they are booked out at the dealership to have diagnostics run on 11/14. I don't know if it is wiring, ambient temperature sensor, max air sensor, HVAC module (dealership had previously cleared water out of the module and then replaced the module, initially when they couldn't find the problem they disconnected the battery and reconnected to reset and clear the code). The dealership in Auburn Al has addressed all the issues and done all the services, updates, and trouble shooting. I'm having to run three different temps in the car and crack the windows when I need heat and AC just crack the windows and adjust the three temps again. I feel like I'm just getting a quick fix each time I go instead of the problem being resolved for good. This has been an ongoing issue especially when the temperature changes (seasons) or fluctuates (throughout the day). I've listed below the most recent start date. I would have to contact that dealership to get the exact timeframe that it ALL started.

This is the second time, while I was driving that the car would not want to pick up speed and shuddered. The engine light came on again. And stayed on this time. I brought it back to the Kia dealer. They ran a diagnostic. They first wanted me to pay the cost. It is under the warranty. Now I am waiting for the parts and was told to not drive my car until it gets repaired. No loaner was offered. They said to drive it home and they will contact me.

I was turning onto a main thoroughfare fare, and the van was slow to accelerate, Engine light briefly blinked, then went off, and then when I was on the interstate I had to pull over the van was running rough. Once I went back on the road, the steering wheel was shuddering and finally the engine smoothed out. This has happened more two other times to me.