What 12 owners told NHTSA about the 2026 Kia Carnival Hybrid Hev

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!

NHTSA ODI 11750230

What component or system failed: The hybrid battery management system (BMS) failed while driving. The dashboard displayed a Battery Management System error along with a lane assist warning. The vehicle then completely lost propulsion, no response from the accelerator pedal, while on an incline, causing the vehicle to roll backward down the hill. The vehicle is currently at the dealership (Kia Temecula) and available for inspection but no one has reached out to me for days. Safety risk: The vehicle lost all forward propulsion while in motion on a hill and began rolling backward, with no ability to accelerate or control forward movement. This posed a serious risk of collision or rollaway accident. I shut the vehicle off and restarted it, which restored partial function for approximately 1 minute before the same failure recurred. Has the problem been reproduced/confirmed: Not yet confirmed by dealer — vehicle was towed to Kia Temecula on 7/12/26 via Kia roadside assistance and is awaiting diagnostic inspection. Dealer scheduling offered August 4, 2026 as the earliest availability, which is unacceptable given the safety nature of the defect. Inspected by manufacturer, police, insurance, etc.: Not yet inspected. Vehicle towed to authorized Kia dealer; diagnostic pending. Warning lamps/messages prior to failure: Yes — Battery Management System error and lane assist function warning appeared on the dash immediately before the vehicle lost propulsion. No prior symptoms were noted before this incident.

NHTSA ODI 11750056

While driving our 1 month old car we intermittently heard a loud clap sound, we assumed it was due to it being a hybrid vehicle. Well on Wednesday we were merging on to the freeway at approx 20 mph when we heard an extremely loud bang and the 3rd window imploded. There was nothing that hit the car, no point of origin for any foreign object, but rather an implosion. How was your safety or the safety of others put at risk? This happened within inches of my child's head and terrified my child. Has the problem been reproduced or confirmed by a dealer or independent service center? We immediately assessed the vehicle was not safe to drive and filed a complaint with Kia Corporate and called the dealership we purchased it from to be assessed and repaired. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? It is currently at the dealership. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? The only oddity was the intermittent clapping sound we heard randomly over the past few weeks of driving our new van.

NHTSA ODI 11748140

2026 Kia Carnival Hybrid – Purchased 9/5/2025 Mileage: 8,450 April 2026- While driving over 60 mph, the vehicle's acceleration failed. A "Hybrid Failure" warning appeared on the dashboard, and the vehicle quickly decelerated. I had seconds to safely cross 3 lanes, and the vehicle had to be towed. The vehicle was at the dealership for 13 days, during which no problem codes were reported, and diagnostic scans appeared normal. No safety feature or diagnostic system reported this failure! I was told to take the vehicle because they had nothing to fix without a diagnostic report. May 2026- I drove the vehicle for a few weeks before this occurred again, with the same warning and complete deceleration. The vehicle was brought to a 2nd dealership, nearest to this incident. They have had the vehicle for 29 days with no safety or diagnostic issues to report and no ability to duplicate the problem. During this occurrence, my daughter was able to video the dashboard and deceleration from the passenger seat. I have provided this video to KIA. The national KIA team is refusing a buy-out option for this vehicle after my family and I have repeatedly been put in danger on the road. It also puts drivers around us in danger as we frantically attempt to proceed to safety while quickly decelerating. It is also extremely alarming that the safety systems and diagnostics do not show that these problems are occurring. While the local dealership has been understanding and professional to date; however, the National brand and its refusal to put safety first, especially on a brand-new vehicle, is unacceptable. We can provide the video and any other documentation you would like. We will be engaging with an attorney after Kia National declined our buyback

NHTSA ODI 11747779

I am reporting an intermittent but serious safety issue with my Kia Carnival involving the backup camera system. Since approximately May 2026, the rear backup camera has failed more than 10 times. When the issue occurs, the display will either: Show a completely blank screen, Flicker repeatedly, or Turn into a solid green screen. Once the failure begins, it continues even after repeatedly turning the vehicle off and back on. The system only starts working again after the vehicle has remained powered off for several hours. This is a significant safety hazard because when the backup camera fails, the parking assist system/sensors also stop functioning. As a result, while reversing, I lose both the camera view and the audible/object detection assistance. This substantially increases the risk of backing into a pedestrian, child, cyclist, or another vehicle, especially in parking lots and residential areas. The problem has occurred more than 10 times over the past several weeks. I have taken multiple videos clearly documenting the failures, including the blank screen, flickering display, and green screen. I have brought the vehicle to the Kia dealership for inspection. However, because the problem is intermittent and could not be reproduced during their inspection, they stated that they were unable to diagnose or repair the issue. Despite this, I have video evidence demonstrating the recurring failure. This appears to be an intermittent electronic or software defect affecting a critical safety system. A backup camera is an important safety feature intended to help prevent backover crashes. The simultaneous loss of both the camera display and parking sensors creates an unacceptable safety risk. I respectfully request that NHTSA investigate this issue to determine whether it represents a broader defect affecting Kia Carnival vehicles and whether a recall or other corrective action is warranted before this defect contributes to a serious injury or fatality.

NHTSA ODI 11747450

I had pickup my vehicle from the dealership where it had been since the 29th of May due to a previous incident exactly the same as what occurred this time. The vehicle had been returned to me as the service department could find nothing wrong from the May 29th incident. On my way home from the dealership, the vehicle started the same as on May 29th. When accelerating from a stoplight, I lost all propulsion. After about 60 seconds the vehicle recovered and I turned to go back to the dealership. At the aforementioned intersection (crossing over I35) it again lost propulsion, only this time for a longer period of time. I was in heavy traffic and the car behind me was honking even though I had my hazard warning flashers operating! I made it to the dealership where the service manager agreed to do a ride along. We were about to the end of the ride along when the vehicle lost propulsion power. It wasn’t as severe and recovered quickly. The service manager said he had noticed the brake pedal move at the time I accelerated. His theory was that the brake being applied at the same time as the acceleration cause the computer to get confused and it’s reaction was to remove propulsion. No offer was given to take the vehicle back for further testing. I dropped the service manager off and proceeded to return home, being cognizant of my foot placement and insuring it was well away from the brake when accelerating. KIA Care has so far refused to get involved. While I recognize braking at the time of acceleration is counterproductive, it should not cause a catastrophic propulsion failure. Plus the system sets no flags that it had this event! I have tried recreating this failure by using my left foot on the brake while accelerating with my right. This doesn’t recreate the problem so it must be a timing issue. I do not know if this issue is unique to my vehicle or is shared with other hybrids! If KIA Care refuses to investiga, the lemon law might have to be invoked!

NHTSA ODI 11742376

We were driving on highway, approximately 2 miles from home, when we suddenly lost power to the drive train. Eventually it started moving again but after a short distance we again lost power to the drive train. It appeared that whenever it transferred from gasoline to hybrid or electric, we would loose power. We were in traffic and this was not a desirable situation. We applied hazard flashers and were able to limp home. We had no way to lock the hybrid into gasoline mode so every time it switch to electric we stalled out and had to wait several minutes before it would transfer back to gasoline mode. Vehicle is currently at dealership for repair but at this time they have not run any diagnosis on the vehicle.

NHTSA ODI 11741107

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.

NHTSA ODI 11740932

-A "Check Hybrid system. Stop safely. " warning has come on 7 times now. The vehicle loses power and slows down abruptly before coming to a complete halt. This has happened on railroad tracks, the highway, and an intersection where my wife and children were almost hit by other motorists. The dealer has not been able to reproduce the code, but we have pictures and videos of said incidents. The vehicle has been inspected by Kia technicians and "fixed" multiple times, but this keeps happening and I will not risk my family's lives any longer. There has been zero warning every time this system failure has occurred. We are undergoing a buyback process with Kia corporate and are prepared to take legal action under Georgia state lemon laws. Thank you for your time.

NHTSA ODI 11734512

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.

NHTSA ODI 11713243

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.

NHTSA ODI 11712656

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.

NHTSA ODI 11697070