28 of the
101 complaints filed about the KIA K4
are about the driver-assist systems —
28% of everything owners reported.
The worst model year for it is 2025.
28
Complaints
28%
Share of all complaints
15
Crashes
0
Fires
Driver Assist & Collision Avoidance complaints by model year
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. •We have had it into the service department 3 times and they were "unable to replicate" in spite of the fact that the second technician was unable to lock/unlock the door while my husband was standing with him. They refused to see the videos that we had of some of the problems.They lied about how far it was driven. 2 of the visits the average speed limit was 23 and 25 mph. Total miles driven: 11 v/s the 39 reported. One visit claims 4 miles but our app shows nothing for the time it was being looked at. •I have asked many times if the computer system had been checked for error codes or glitches and no one will answer the question. •No warning lights, just MANY obvious computer system problems
NHTSA complaint #11755719 — an unverified report by a vehicle owner.
I am submitting this complaint regarding a suspected safety defect involving a 2025 Kia K4. On XXX, the vehicle was involved in a single-vehicle crash in the Town of [XXX]. According to the driver, the vehicle unexpectedly steered off the roadway when the Lane Keeping Assist/Lane Centering steering system appeared to intervene. The driver attempted to maintain control but was unable to keep the vehicle on the roadway. The vehicle entered a ditch and struck a utility pole, causing significant damage to the passenger side. The front and rear passenger-side airbags deployed. The front passenger window shattered, sending broken glass onto the front and rear passengers. My daughter was seated in the front passenger seat, and my [XXX] granddaughter was properly restrained in a rear child safety seat. Both sustained injuries and required medical evaluation following the crash. After the collision, I began researching similar incidents and found other owners reporting concerns involving the steering assistance and lane-keeping systems. While I cannot determine the exact cause of this crash, I believe the possibility of an unintended Lane Keeping Assist or steering system intervention should be investigated because it may present a safety risk to other motorists. I respectfully request that the National Highway Traffic Safety Administration review this incident, along with any similar complaints involving the 2025 Kia K4, to determine whether a defect exists in the vehicle's steering assistance, Lane Keeping Assist, Lane Following Assist, or other Advanced Driver Assistance Systems (ADAS). Supporting documentation can be provided if requested. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11753551 — an unverified report by a vehicle owner.
The contact owns a 2025 Kia K4. The contact stated that while driving at 75 MPH, the vehicle downshifted upon depression of the accelerator pedal, with heavy white smoke coming out of the exhaust pipe. The contact stated that the low oil pressure warning light was illuminated prior to the failure. The contact pulled off the highway and drove into a store parking lot as the engine made an abnormal knocking sound. The contact requested assistance from a bystander, who advised the contact that the head gasket appeared to have blown. The contact checked and noticed that the coolant and oil levels were low. The contact added both oil and water to the vehicle and drove to the residence. The contact made a diagnosis appointment with a local dealer. Upon starting the vehicle, the check engine warning light illuminated, and the contact decided to tow the vehicle to the dealer. The dealer determined that the engine needed to be replaced due to sludge. Additionally, the contact stated that the vehicle had experienced various electrical failures, as the trunk, power door, and power windows buttons were inoperable. The contact also stated that the rearview camera image remained displayed while in drive(D) for an extended period. The contact was provided an estimate for the repair, and the vehicle remained in the dealer's possession. The manufacturer was notified of the failure and provided a case number. The vehicle was not repaired. The failure mileage was approximately 58,000.
NHTSA complaint #11743732 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
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.
NHTSA complaint #11741355 — an unverified report by a vehicle owner.
The warnings on the car all failed and I was lead off the road while going on a roundabout. This has trigged my car to completely lose all control and even though I was attentive to my steering wheel I still didn’t stop the car from leading me to that curb and off road onto grass etc.
NHTSA complaint #11739853 — an unverified report by a vehicle owner.
The contact owns a 2026 Kia K4. The contact stated while her daughter was driving at approximately 25 MPH, the lane assist feature was diabled however, the contact attempted to avoid a dog and the vehicle independently jerked the vehicle and caused the front driver side of the vehicle to crash into a fence. No warning lights were illuminated. The air bags were not deployed. The vehicle was taken back to the residence. A police report was filed. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 465.
NHTSA complaint #11738505 — an unverified report by a vehicle owner.
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
To whom this may concern, I was using my cruise control on my way to work. I usually set it to 80 because police are okay with that speed on I-75. I braked before my automatic brakes hit after I got cut off. I pressed resume in the cruise control and it accelerated pretty quick. I’ve experienced that quite a bit, but there’s been a few times that the car exceeded the set cruising speed while trying to resume. I forget it happens because it’s happened about 4 times since purchasing the vehicle. I noticed an officer on the shoulder leaving the shoulder as I got closer, and he got right behind me and cut his lights on, I look down and the cruise control shows 80 above the speedometer (photo attached taken while pulled over), BUT the arm was past the tick for 90. The officer clocked me at 92 apparently. This is the only time this issue has occurred, and I informed the officer that this happens. I have a court date set for July 9th now. I Googled to see if other owners have this problem. There are others who expressed experiencing this in their K4s and K5s. The AI tool explained the following • "Resume" Behavior: When you press the resume button, the car attempts to get back to 80 mph as quickly as possible. This aggressive acceleration can cause it to temporarily overshoot the target speed before settling down. • Settings Sensitivity: The acceleration strength and reaction speed can be set to "Fast" in your infotainment system, causing more aggressive throttle input.
NHTSA complaint #11737989 — an unverified report by a vehicle owner.
Sometimes when I’m driving the steering wheel just jerks to the left sometimes causing me to swerve into incoming traffic. It’s very scary. Luckily I’m holding tight to the steering wheel to keep myself from hitting someone.
NHTSA complaint #11733624 — an unverified report by a vehicle owner.
Sometimes when I’m driving the steering wheel just jerks to the left sometimes causing me to swerve into incoming traffic. It’s very scary. Luckily I’m holding tight to the steering wheel to keep myself from hitting someone.
NHTSA complaint #11733624 — an unverified report by a vehicle owner.
Steering Instability: The steering wheel would periodically veer to the right and left on its own without my input. This created an unsafe driving condition and required constant correction to maintain control of the vehicle. Blind Spot / Reverse Detection Malfunction: When shifting the vehicle into reverse, the dashboard display indicated that no vehicle was present. However, when visually checking my driver-side mirror, there was clearly a vehicle immediately adjacent to my car. The system failed to detect or warn of the nearby vehicle, creating a significant near missed accident and safety risk.
NHTSA complaint #11720323 — an unverified report by a vehicle owner.
Steering Instability: The steering wheel would periodically veer to the right and left on its own without my input. This created an unsafe driving condition and required constant correction to maintain control of the vehicle. Blind Spot / Reverse Detection Malfunction: When shifting the vehicle into reverse, the dashboard display indicated that no vehicle was present. However, when visually checking my driver-side mirror, there was clearly a vehicle immediately adjacent to my car. The system failed to detect or warn of the nearby vehicle, creating a significant near missed accident and safety risk.
NHTSA complaint #11720323 — an unverified report by a vehicle owner.
When parked and cutting the car on check driver assistance system come on, check and, and esc comes on. The parking brake does not go off and malfunction. When trying to move the car sometimes it still drives and sometimes the parking brake will not allow you to move until the system resets its self. There are 6 codes that appear. Started in December 2025 have taken car to the dealership 3 times and they report back because the codes are no longer present they can not fix it.
NHTSA complaint #11718311 — an unverified report by a vehicle owner.
When parked and cutting the car on check driver assistance system come on, check and, and esc comes on. The parking brake does not go off and malfunction. When trying to move the car sometimes it still drives and sometimes the parking brake will not allow you to move until the system resets its self. There are 6 codes that appear. Started in December 2025 have taken car to the dealership 3 times and they report back because the codes are no longer present they can not fix it.
NHTSA complaint #11718311 — an unverified report by a vehicle owner.
The insurance claim agent called on behalf of their insured driver, who rented a 2025 Kia K4. The contact stated that while their insured driver was attempting to reverse, the reverse sensor became inoperable with no warning lights illuminated. The contact stated that the reverse sensor failed to function properly. The contact stated that due to the failure, the rear of the vehicle crashed into a barrier. The driver did not suffer any injuries, and no medical attention was required. A police report was not filed. The contact stated that the air bags did not deploy during the incident. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The rental company was made aware of the failure, and a case was opened. The failure mileage was not available.
NHTSA complaint #11717827 — an unverified report by a vehicle owner.
There are times my vehicle keeps accelerating even though I’m hitting the brakes. Once stopped, it then doesn’t want to accelerate. I’ve reported to the dealership and they try to tell me it’s the type of transmission it has and that it’s normal. Continuing to accelerate while braking is extremely unsafe. My engine is also making a ticking noise that it never used to make. I bought my car brand new in October of 2025. I left the dealership with 9 miles on it, I now have 25k miles on it and I don’t feel safe driving it. The lane assist and emergency braking system is also extremely inaccurate and over corrects when it shouldn’t especially in bad weather. Emergency braking is detecting stuff in front of me that isn’t actually there, same with in reverse it sees things extremely far away and prevents you from moving, although it’s safe to do so.
NHTSA complaint #11711366 — an unverified report by a vehicle owner.