*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Engine
The contact owns a 2026 Kia K4. While driving 37 MPH, the vehicle lost motive power. After restarting the vehicle, the failure persisted, and the message "Press Engine Start/Stop" was displayed with the key warning light illuminated. The following night, the contact started and then turned off the vehicle; however, the vehicle restarted independently without the Engine Start/Stop button being pressed. The vehicle was towed to the dealer but was not yet diagnosed. The manufacturer was notified by phone, and a case was filed. The failure mileage was 25,352.
Oct 6, 2026 · 25,352 milesStructure › Body
On August 26, 2026, at approximately 5:30 PM, while driving home from work at about 55 MPH, the factory panoramic sunroof glass of my brand-new 2026 Kia K4 spontaneously shattered and catastrophically exploded without any external impact. The sudden, deafening blast sounded like a gunshot or like another vehicle had crashed into me, though I felt no physical impact. This intense noise created an extreme safety hazard as I swerved due to a panic reaction, and could have lost control of the vehicle, or caused a multi-car collision during rush hour traffic. Fortunately, the interior sunshade fabric was completely closed at the time, which prevented the shattered tempered glass from showering…
Aug 26, 2026SteeringCrash
Driving home, the entire screen flickered, then went out, when it came back the drivers assist lane assist kicked in and the car steered itself into oncoming traffic, which forced an oncoming car in front had to lock its brakes to avoid a collision. Then after forcing the steering out of the incoming lane, the lane assist came back on causing collision with the curb in the opposite direction. After resetting the computer with a pin, and watching the screen flicker and blink, it came back on and now the car is parked at home. Hewitt police would not come out because it was in Waco (the car is garaged in Hewitt), and Waco police said it was not in their jurisdiction so no police report was…
Sep 27, 2026SteeringCrash
On August 28, 2026, I was driving my 2026 Kia K4 GT-Line with approximately 1,872 miles at low speed in a parking lot. While making a left turn at the end of an aisle, I attempted to straighten/unwind the steering wheel. The steering became unusually unresponsive and I was unable to straighten the vehicle as expected. The vehicle continued left and struck a curb, causing body and front suspension damage. The abnormal steering behavior occurred before the curb impact. I observed no power steering, check-engine, ADAS, or other warning lights or messages before or during the incident. An authorized Kia dealer inspected the vehicle before collision repairs. The dealer documented my report that…
Aug 28, 2026Unknown or other
The vehicle has repeatedly jerked into other lanes while I am driving, requiring me to quickly jerk the steering wheel back to avoid a collision. This occurs whether the lane-keeping assistance feature is turned on or off. I turned the feature off, but the problem continued. The vehicle does not feel safe to drive and appears likely to cause an accident, especially when there is oncoming traffic.
Sep 18, 2026Air bagsCrash
Was in a side impact collision on july 17, 2026, vehicle was totaled but no air bags deployed nor did any collision sensors go off
Jul 17, 2026Steering
The vehicle issues began 3 weeks after purchasing a 2026 Kia K4 with 89 miles on it. *"Key fob not recognized", black screen, car not starting and cascading into many other infotainment problems. ** Revving far higher (1.4 - 4.4) with the slightest acceleration ***Hesitating, them engaging so suddenly that steering is incredibly difficult. On more than one occasion, of someone had been in front of me, I would have hit them. ****All steering assist options OFF yet the car will take control and turn me towards oncoming traffic. I absolutely could have been in/caused a serious accident. â¢We have had it into the service department 3 times and they were "unable to replicate" in spite of the…
Jul 10, 2026Forward collision avoidance › Adaptive cruise controlCrash
The contact owns a 2026 Kia K4. The contact stated that on several occasions while driving at various speeds with the smart cruise control activated, the brake was applied inadvertently and the steering wheel steered to the right, overcorrecting his steering efforts. The contact state that the inadvertent braking and steering nearly caused the vehicle to crash and almost resulted in the vehicle being rear-ended by another vehicle. The vehicle was taken to a dealer where it was diagnosed that the vehicle operating normally and there was no failure replicated. The manufacturer was notified of the failure and multiple complaints were filed. The failure mileage was unknown.
May 5, 2026
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.
