2026 Kia Carnival Hybrid

I am writing to formally express my serious concern and disappointment regarding my Kia Carnival Hybrid. Shortly after purchasing the vehicle, with only approximately 6,000 miles on the odometer, the vehicle suddenly stopped operating while I was driving on the freeway. This created a dangerous situation for my family and other motorists. The vehicle had to be towed to an authorized Kia dealership for diagnosis and repair. No warning or message had appeared before the issue. The dealership retained the vehicle for approximately one week and informed us that a PCB (Printed Circuit Board) component had failed and needed to be replaced. After the repair was completed, we were assured that the issue had been resolved and that the vehicle was safe to drive. Unfortunately, after driving only about 50 additional miles, the exact same issue occurred again. The vehicle once again became inoperable, leaving us stranded and raising significant concerns about the reliability, safety, and quality of this vehicle. We towed the vehicle on 6/22/26 and Kia dealership had it till today 8/7/26 and corporate keep saying they working on it but unresponsive.

I own a 2026 Carnival Prestige SX Hybrid and having loss of propulsion problems. After much research, and absolutely no help from KIA, I now think my problem is my foot, size 15, is too large to safely drive this vehicle. My shoe intermittently depresses the brake ever so slightly while I accelerate from a stop. This triggers the Brake-Throttle Override which temporarily cuts propulsion power. The BTO is in all US cars but of the five vehicles (2025-26, different manufacturers) I have driven this past six months, this is the only one that has given me concern for my safety! KIA claims the vehicle is operating as expected! I claim that they have engineered the brake and acceleration pedals too close to each other creating a serious safety issue for those of us with larger foot sizes. The owners manual makes no mention of the BTO function nor how to restore propulsion once the BTO has been activated! While all US vehicles have the BTO function, they vary as to how the function performs. In KIA, once the BTO is triggered, all propulsion is suspended! The BTO was designed to prevent runaway acceleration. In this KIA, they have created a new safety problem because they failed to allow enough space for larger footed individuals room to safely operate their vehicle! KIA needs to introduce a foot size requirement for all prospective buyers or redesign the area around the accelerator and brake pedal so safety is no longer an issue!

While driving a brand new Kia Carnival Hybrid (purchased yesterday), I experienced a severe, life-threatening powertrain acceleration lag from a rolling start. My children were in the car and this was very scary. When attempting to accelerate into oncoming traffic on a wet road surface, the vehicle completely hesitated and dropped power for approximately 1.5 to 2 seconds, leaving the vehicle stranded in the path of oncoming traffic. When the power finally engaged, it delivered a violent surge of torque that caused the front tires to break traction and squeal aggressively. This software-driven hesitation and power-distribution lag represents a severe safety hazard.

On the highway, the vehicle would not accelerate and was losing speed even though the gas pedal was fully depressed. Initially, the vehicle was in ECO drive mode, traveling approximately 65 mph and the steering wheel paddle to toggle the regenerative breaking between levels 1-3 prior to getting onto the highway. The vehicle speed dropped from ~75mph into the low 50mph range on the highway and was able to maintain speed then slowly regain speed when then phenomenon would happen again. The engine light was not initially on but did come on eventually. The engine light flashed at first but then stayed solid. Eventually a safe space was found on the side of the highway to pull over and restart the car. After restarting, the vehicle was able to regain highway speed (using caution, slow acceleration to merge back onto the highway), however when attempting to accelerate faster to see if the problem persisted, it did and the car again would not accelerate even when fully depressing the gas pedal. It felt similar to when you push the gas pedal while in park where the engine revs with high rpm's but doesn't move. The road trip was completed using cruise control, which seemed to have less issues (although not zero issues). After exiting the highway, at lower speeds (<30mph) the vehicle was shaking like it was going over rumble strips until it could be turned off and restarted. Component: power train. Yes, it is available for inspection. Safety issue: While traveling on the highway at times, the vehicle lost speed, was unable to maintain speed and/or accelerate. This could have easily caused a crash at highway speeds (60mph+). inspected by others? No. Will be taken to dealer on 11/3/25 Warning lights: The engine light came on after the initial incident. Kia Connect app, the following diagnostic codes were received; P030000, P030100, P030300.