2025 Kia Carnival Hybrid: sudden loss of power

Filed Oct 22, 2026 · Acceleration, Fuel system · TX

My 2025 Kia Carnival Hybrid was purchased new in January 2025. The problem began almost immediately, with the vehicle first presented to an authorized Kia dealer for this condition at only 810 miles. The vehicle repeatedly and unpredictably enters reduced-power or “limp mode,” causing a sudden loss of normal acceleration and limiting it to approximately 35 mph. This creates a serious safety risk on highways, while merging, crossing intersections, or whenever acceleration is needed to respond to traffic. Equally concerning, the vehicle does not consistently display a warning or retain a hard diagnostic error code when the loss of power occurs. Sometimes a check-engine light or “Check Hybrid System - Stop Safely” message appears, but at other times the vehicle enters limp mode with no warning. After turning the vehicle off and restarting it, normal operation may return and the error disappears, leaving the dealer unable to retrieve a stored code showing what occurred. The vehicle has been presented to an authorized Kia dealer for this recurring issue at least five times. In August 2026, it remained in limp mode and had to be towed to the dealer. We were initially told no error code had been found. Near the end of the service period, we were told a code had appeared indicating a faulty sensor, which was replaced, but the reduced-power problem later recurred. The vehicle’s automatically generated August performance report also indicated no vehicle issues despite the August incident. A Kia TechLine case was later opened, but the recurring problem was not identified or permanently corrected. The vehicle is available for inspection.

Filed Jul 10, 2026 · Acceleration, Fuel system · ID

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. Because this defect affects the vehicle's ability to accelerate safely in traffic, I am deeply concerned that it could result in a serious collision if it happens again. I took it into the dealership and the service center experienced the same issue. They thought they had resolved the issue and that it was a "one off" occurrence but it happened to me again just 3 weeks after the attempted repair. This time the engine light came on after the "Check Hybrid System" warning light.

Filed Jun 16, 2026 · Engine · TX

Van made a loud pop noise and lost power. The HSG belt tensioner spring fell off it's seat loosing tension on the HSG belt. Was unsafe but luckily it happened before getting on the freeway, and coasted into a parking lot. Yes, it's at the dealership getting a replacement tensioner and belt. I believe so. No notification prior to failure, it was sudden.

Filed Apr 5, 2025 · Fuel system, Transmission · UT

Vehicle lost power and would not accelerate past 30 mph even when fully pressing down on the accelerator. After a few minutes a warning flashed to check vehicle hybrid system. Pulling over to the shoulder and restarting the car returned the car to normal operation.

Filed Mar 18, 2025 · Acceleration, Electrical · UT

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. The dealership is still saying they can’t fix what they don’t know is wrong. Which I get, but it’s weird that these major events aren’t being recorded by the car. And it is terrifying to suddenly lose power on the freeway.

Filed Jan 23, 2025 · Acceleration, Engine · MD

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. To that, I said “but if the car thought there was something in front of us, it would have applied emergency braking, not just simply stopping any acceleration”… to which they replied “yeah I don’t know. Cars these days are just a giant rolling computer”. The dealer just could not replicate the issue, so they had no way of really seeing or diagnosing it, which I understand but still frustrating. They said they drove it 3 times but it didn’t happen. But again, it happens randomly (though cold weather seems to be a common factor). So we left and said okay, they tried, they cleared off the camera, let’s see what happens. One week later (this morning) happened again. Taking into the dealer this evening. We have a Case open with the Kia Customer Care “Escalations” team. But they’ve been no help.