2024 Kia EV9: sudden loss of power

Filed Oct 30, 2026 · Electrical, Fuel system · OR

The vehicle failed without warning while driving. In sequence, it displayed an electrical system warning, then a 12V battery error, dropped into reduced-power “turtle” mode, shifted itself into neutral, sat immobile while throwing multiple warning lights, and then lost all power completely. It had to be towed to local Kia for diagnosis/repair. Losing motive power while driving in traffic is a serious safety hazard that put the occupants and others around the vehicle at risk.

Filed Dec 30, 2025 · Electrical, Engine · WA

I would also like to highlight the serious safety concern due to cell deviation (imbalance) along with SOC (State of Charge) mismatch as per my car's BMS (Battery management system) which is present in my vehicle and shared with Kia corporate. In an electric vehicle, the high-voltage battery cells, the Battery Management System, and the battery coolant system function as a single integrated safety-critical system. When battery cells are imbalanced and there is a significant mismatch between the state of charge displayed to the driver and the lower usable energy calculated by the Battery Management System, the weakest cell can reach its safe operating limit under normal driving load even though the dashboard indicates sufficient charge. If this condition is combined with a battery coolant system fault, such as low coolant level or air in the cooling circuit, battery temperatures can rise unevenly and further reduce safe operating margins. To protect the battery and prevent thermal or electrical damage, the system must immediately limit propulsion or enter a reduced-power (“turtle”) mode without driver input. Because these protective actions can occur suddenly and without advance warning, they can restrict acceleration or vehicle speed during ordinary driving conditions such as merging or maintaining highway speed, creating an unexpected loss-of-propulsion safety risk rather than a mere inconvenience. This is equivalent to a faulty fuel gauge for a gasoline car but with more immediate and severe consequences Sudden Power Cutoffs: If a single battery cell's voltage drops below a safe threshold, the Battery Management System (BMS) will shut down the entire pack to prevent permanent damage. This can happen even if the dashboard shows 25% or more remaining, potentially leaving you without power while driving. Loss of Vehicle Control: A sudden shutdown can lead to a loss of power steering and braking assistance, which is hazardous in high-speed or heavytraffic situatio

Filed Aug 28, 2025 · Electrical · NM

Received the following warning on 8/16 with 6987 miles on the car: Critical EV Battery Warning Your EV Battery has a critical issue. Contact Roadside Assistance as soon as possible. Car has been in the dealership for a week with "no estimated repair timeline" due to the battery cells failing. Car will not fully charge and is at risk of suddenly losing power and stopping, per the dealer.

Filed Aug 22, 2025 · Acceleration, Electrical · CA

While driving, the vehicle suddenly lost power and could not accelerate normally. The speed dropped and got stuck around 12–25 mph even when pressing the accelerator. This happened multiple times, usually during hot daytime conditions. It created a serious safety risk, and one time another car almost hit me from behind because my vehicle slowed down so suddenly. The dealer has inspected the car several times but said they could not reproduce the problem. Warning messages such as “Power Limited” appeared on the dashboard when the failure occurred. I also recorded multiple videos of the problem when it happened.

Filed Mar 19, 2025 · Fuel system · CT

Starting on Feb 22, 2025, we observed that our Kia EV9 had dramatically reduced range. Normally, when charging was complete the dashboard would show well over 250 miles of range, even in cold weather. On Feb 22nd we started to see the range had dropped to around 60 miles, even when the dashboard reported the battery at 100% charge. The actual range seemed to be even worse, dropping dramatically even after a short drive around our town. By all appearances, the high voltage battery seems to be defective and is causing a safety issue because it could result in a sudden loss of power during driving or an unexpected shutdown of the vehicle. This may also be a symptom of an even more serious battery defect that could result in a battery fire. We brought the vehicle to the dealer, and they were able to reproduce the severe drop in range. No components have been replaced yet, we are still waiting to hear which parts will be replaced under warranty service. During this entire time the vehicle has given zero warnings or alerts, including no warning messages nor the check engine light.

Filed Jan 29, 2025 · Body, Brakes · WA

The 12-volt battery for the vehicle was depleted, so the vehicle had to be jump-started to run. I work for a repair facility (it was here for collision repairs, as far as I know unrelated to this issue) and since I was unfamiliar with the vehicle, I inadvertently turned it off before shifting into park. When I took my foot off the brake, the vehicle began to roll forward. I am not sure if the vehicle was in park, neutral, or even reverse (the gear I was in when I turned the vehicle off), but whatever gear it was, the vehicle kept rolling after it was turned off. I tried turning the vehicle back on to shift to park, but was unable to do so due to the depleted 12-volt battery. I tried hitting the park button anyway, and this did nothing. I then tried to engage the electronic parking brake, but this was also inoperative due to the lack of power. With each attempt, I tried briefly taking my foot off the brake, but each time it continued to roll forward. I then called my manager and asked him to jump start the vehicle so I could put it in park and engage the parking brake. No damage was done in this incident, nor was anyone hurt, but this lack of fail-safes to prevent the vehicle from moving after a loss of power is a significant design flaw and safety hazard. If I had not noticed the issue in time and gotten out, the vehicle could have rolled away and caused property damage or bodily injury to me or a bystander. To my knowledge, this is the only such incident with this vehicle, and I do not know whether it is specific to this particular vehicle or replicable in others of the same year make and model. There were no warning lights.

Filed Nov 13, 2024 · Electrical, Fuel system · MI

My family and I were driving down a busy highway at speed in the middle lane, the vehicle suddenly jolted forward and lost power. Dashboard reported electrical system failure, contact service. Vehicle was recovered to dealer who has been unable to resolve issue and KIA unable to diagnose the root cause of the problem. Very dangerous.