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.

Detailed information is in the attached pdf file, but in a nutshell, Kia is covering a safety defect in their vehicles by claiming the process is “proprietary”. On several occasions we have lost propulsion, which means we had no control over our vehicle, and Kia’s explanation is simply, “the vehicle is performing as intended “! These incidents always happened at low speeds, just accelerating from a stop, but left us in a precarious situation as we were left in the middle of a busy intersection with no control over our vehicle! Propulsion would eventually return. After surviving several of these failures, I learned the proper thing was to let both pedals return to their idle position and then the vehicle would recover. This is a most difficult thing to accomplish when surrounded by angry drivers! The failures were identified by Google AI as a Brake Override System, also known as Brake Throttle Override. However, Kia already has a very functional Brake Over Accelerator process, so why would they have two similar functions? Kia knows the answer but is refusing to divulge any information regarding the intention or purpose of this mysterious process which makes our vehicle unsafe!

While driving on an interstate during a heavy summer thunderstorm, the vehicle suddenly displayed a warning stating, "There may be a problem with the Battery Management System," along with a "Check Hybrid System" message. At the same time, the check engine light illuminated and the hybrid system stopped functioning without any prior warning. Approximately 10–15 minutes before the incident, I had driven through approximately 4 inches of standing water on a surface street at a speed of about 25 mph. After entering the interstate and traveling at approximately 65 mph in heavy rain, the hybrid system suddenly disabled itself. Cruise control was not engaged at any point during the trip. Immediately after the warning appeared, the vehicle experienced a significant loss of power and entered what appeared to be a reduced-power (limp) mode. The gasoline engine continued to run, but acceleration was severely limited, making it difficult to maintain speed or accelerate with surrounding highway traffic. This occurred at night, during heavy rain, on a busy interstate.The unexpected reduction in power created a hazardous situation and increased the risk of being struck by other vehicles while attempting to merge or pull over. After I was able to safely stop and restart the vehicle, the "Check Hybrid System" and Battery Management System warning messages disappeared. The vehicle has approximately 6,000 miles and was purchased new. This vehicle is used to transport my family, including my wife and our three young children. I believe this presents a significant safety concern because the sudden loss of power occurred without warning while traveling at highway speed in adverse weather conditions. Even though the vehicle remained drivable, the reduced acceleration made it difficult to safely maintain traffic flow or move to the shoulder, increasing the risk of a collision. I request that this issue be investigated to determine whether there is a defect affecting the hybrid system.

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.

Driving on freeway with the heater on, Cold weather, car had multiple issue messages (transmission control unit and adaptive cruise control) as well as a check engine light come on as the car went limp and would not accelerate. Has to pull off of the freeway after nearly getting in multiple accidents due to losing speed from 65 mph to 30. Had the gas pedal all the way to the ground and the car would barely accelerate.

Without presenting any errors, the vehicle appears to enter some sort of limp home mode which limits speed to 31mph until the vehicle is turned off and re-started. 31mph is well below the speed limit on most public roads and being limited to this speed with no ability to pull over to stop/start the car creates a significant safety hazard to the driver of the vehicle and other motorists.

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.