2017 Kia Optima: adaptive cruise control problems

Filed Dec 30, 2025 · Electrical, Engine · 98,000 miles · UT

The contact called on behalf of her daughter who owns a 2017 Kia Optima. The contact stated while driving at approximately 60 MPH, the vehicle made an abnormal knocking sound, the cruise control was inoperative, the infotainment screen darkened, and the charging outlet was inoperative. The Check Engine warning light was intermittently illuminated. The vehicle was taken to the contact's residence, and the contact used a vehicle scanner to scan the vehicle. The contact stated that DTC: P1326 for the Knock Sensor Detection System (KSDS) was found, which detected excessive engine vibration. A dealer was contacted; however, the vehicle was not diagnosed or repaired by the dealer. No further information was available. The failure mileage was approximately 98,000.

Filed Sep 1, 2023 · Acceleration, Engine · WA

First I had an oil leak which I was advised to warm my car up to prevent from getting worse. At the time I was told it was minor. Then my oil light started coming up every 2 weeks and when checked there was no oil. Now 2 months later, my car has stopped and showed a blinking check engine light. When checked I was told a code of p1326 which is the knock sensor. I have only had my car 7 months and it’s been problem after problem. Not to mention only a month after buying it was stolen. Due to no immobilizer So I’m sure a lot of the issues are also a result of the dumb theif who decided to damage my car. Also my cruise control doesn’t work a lot of the time.

Filed Jul 24, 2023 · Acceleration, Driver assistance · CA · crash · 2 injuries

On 6 June 2022 I was driving Eastbound Interstate 80 passing Fairfield, CA. Traffic was moderate, average traffic speed 65. The Kia’s Adaptive Cruise was enabled and set to the maximum amount of safe distance. I recall the car directly in front of me changed lanes to pass a truck towing a trailer. I remember the Kia began to accelerate and I couldn’t turn the wheel. Next memory was opening my eyes to the dust smoke of deployed air bags. I lost consciousness likely due to the sudden impact and air bags deployed. I was taken to a Fairfield hospital by ambulance where I spent 4 days. A slurry of tests ruled out loss of consciousness as the cause. No stroke, heart attack or seizure occurred. I was treated for bruised ribs due to the airbag. No doubt to me that this collision could have been catastrophic to this driver and others driving nearby. Witness reported that I sped up and clipped the truck/trailer while attempting to pass. What I believe happened: 1) the Adaptive Cruise accelerated when it determined there was room but failed to see the trailer and 2) the steering was unresponsive when I attempted to avoid a collision. The reaction time between car accelerating and getting knocked out had to be a mere three or four seconds. The vehicle was totaled, The insurance company, Mercury Insurance, released the vehicle

Filed Mar 14, 2023 · Driver assistance · CA

Cruise control does not maintain a steady speed and constantly fluctuates 10+- miles an hour! The dealer refuses to fix and says they cannot reproduce the symptom. I used a tracker and saw the dealer drive it around the block, never attempting to put it on the freeway.

Filed Sep 23, 2022 · Acceleration, Driver assistance · GA

I was driving with an SUV in front of me at 18-wheeler in front of them. This is on a road where the speed limit is 65 however there's a section on 301 where there's a traffic light. All three vehicles came to a slow normal stop and the adaptive cruise control was doing a good job of slowing the vehicle down without my input. But the SUV when we were at about stopping speed but had not yet come to a complete stop, the SUV switched to the left lane. At which point I was maybe 20 ft behind the 18-wheeler and all of a sudden the car is adaptive cruise control tried to accelerate the car back up to the setting of 65. It didn't register the 18-wheeler at all It just registered that the car in front of me had cleared the space and if I had not been paying attention and immediately applied the brakes to stop the car manually It absolutely would have accelerated directly into the back of the 18-wheeler. I was maybe 5 ft and it was still accelerating when I slammed on the brakes. I've been able to since reproduce the effects, it doesn't register 18 wheelers correctly in this specific situation as vehicles. I've even had the camera recalibrated in between tests. I have everything on video but unfortunately do not have access to the car's computer logs. I would be willing to send in my ECU for whatever is needed to identify this further.