Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Kia Optima owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owned a 2015 Kia Optima. The contact stated while driving 40 MPH, he noticed an abnormal burning odor; however, the temperature gauge did not indicate that the vehicle was overheating. The contact stated that upon noticing that the burning odor was becoming stronger, the contact pulled to the side of the road and turned off the vehicle. The contact stated that while exiting the vehicle, he noticed flames coming out through the upper part of the hood, near the windshield. The contact opened the hood and noticed that there was fire under the hood. The contact stated that the fire expanded, and the vehicle significantly burned from the front end to the rear seats. The fire was extinguished by the fire department. The contact was unsure whether a fire department report was filed. …
The contact owned a 2015 Kia Optima. The contact stated that while driving at 60 MPH, during a DoorDash delivery, the vehicle vibrated. The contact pulled to the side of the road and noticed smoke emitting underneath the vehicle from the right side. The contact exited the vehicle and noticed smoke emitting from underneath the hood. The state troopers were called. By the time the fire department arrived, the vehicle was engulfed in flames, and the engine had exploded. The fire department extinguished the fire. The contact was not injured. No police report was filed. The state troopers believed that the fire was caused by an electrical short. The contact stated that prior to the fire, the vehicle vibrated when idled. No warning lights were illuminated. The vehicle was towed to a towing yard. The insurance company was not notified about the fire. …
The contact owns a 2015 Kia Optima. The contact received notification of NHTSA Campaign Number: 21V331000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not yet available. The contact stated that while driving at an undisclosed speed, the brakes failed to stop the vehicle immediately, causing the vehicle to crash into a curve that fractured the lower control arm and damaged the tire rims, fender, and bumper. Additionally, the vehicle later failed to start. The dealer was made aware of the failure but confirmed that parts were not yet available. The vehicle was taken to an independent mechanic and diagnosed that either the alternator or battery was faulty. The mechanic replaced the lower control arm. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was 129,403. Parts distribution disconnect.
The contact owns a 2015 Kia Optima. The contact stated that while driving approximately 75 MPH, the vehicle lost power and the check engine light was illuminated. The vehicle was parked at the residence. The vehicle was taken to an independent mechanic where it was diagnosed that a handheld diagnostic machine provided code: P1326 where the knock sensor needed to be replaced. On another occasion, while driving at 20 MPH, the vehicle stalled. The contact attempted to start the vehicle again but observed smoke and flames emanating from the engine compartment and exited the vehicle. The fire department extinguished the fire. A police report was filed. The vehicle was towed to a dealer where it was diagnosed that the knock sensor needed to be replaced. The manufacturer was notified of the failure. The failure mileage was 152,451.
The contact leased a 2015 Kia Optima. The contact stated that the front passenger's side window, the rearview camera, and the brake lights were intermittently inoperable. Additionally, the contact stated while driving at approximately 10 MPH, the check engine warning light and several unknown warning lights illuminated, and the vehicle shut off. The contact shifted into neutral(N) and was able to push the vehicle to the side of the road with the assistance of several bystanders. The vehicle was towed to the residence. The vehicle was then towed to the dealer where it was leased, and it was diagnosed that the engine had seized and needed to be replaced. The engine was replaced; however, the failure persisted. The contact stated while driving at an undisclosed speed, the battery warning light and the steering warning light illuminated, and the vehicle shut off. …
The contact owns a 2015 Kia Optima. The contact stated while her granddaughter was driving at an undisclosed speed, the vehicle lost motive power and there was smoke coming from the front end of the vehicle. The driver was able to pull to the side of the road and turned off the vehicle. The contact met her granddaughter on the side of the road. Upon inspecting the vehicle, the contact noticed that the smoke was coming from underneath the vehicle, under the engine compartment. The vehicle was towed to an independent mechanic, where the contact was informed that an unknown wiring harness had burned, but the cause of the failure could not be determined. The vehicle was towed to the dealer, where it was diagnosed that the engine had seized and needed to be replaced. The was not repaired. …
Yesterday, [redacted], My 2015 kia optima engines reved up wothout me pushing the gas & within seconds later a loud noise and metal fell from under the hood. After pulling over, popping the hood on the passenger side and under the engine a fire had started. My daughter was seated in the back passenger side her door had locked, thankfully the passenger door was left opened bc within minutes the entire car was filled with smoke and engulfed in flames. Prior to this the steering wheel would jerk even while at a red light. This car just did have 100,000 miles & no knowledge this prior. Thank god i was able to get my daughter out of this vehicle & this didnt end in a tragedy due to negligence if this was a prior known fact.
The contact owns a 2015 Kia Optima. The contact stated that the check engine and battery warning lights were illuminated. The contact stated that the engine had been replaced two weeks prior to the failure. The vehicle was taken to a local dealer for routine maintenance; however, the cause of the failure could not be determined. In addition, during a battery replacement, there were several unknown warning lights illuminated and smoke was coming from the vents. The vehicle was towed to a local dealer where it was diagnosed that there was an EVAP leak, the canister purge valve had cracked, and the battery needed to be replaced. The vehicle was not repaired. The contact referenced Kia Campaign Number: SC135. The manufacturer was made aware of the failure. The failure mileage was approximately 160,000.
The contact owns a 2015 Kia Optima. The contact received notification of NHTSA Campaign Number: 21V331000 (Service Brakes, Hydraulic) however, the part to do the recall repair was not available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated while driving 60 MPH, the vehicle stalled without warning. The contact was able to coast the vehicle off to the shoulder of the roadway. The contact mentioned that the battery was drained from the engine not turning off. The vehicle was towed to the dealer but not diagnosed nor repaired. The vehicle was undrivable. The manufacturer was notified of the failure. The failure mileage was approximately 56,000. Parts distribution disconnect.
The contact owns a 2015 Kia Optima. The contact stated while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. Additionally, the check engine warning light illuminated, and the vehicle turned off unintendedly. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure; however, the contact was informed that the repair was not covered under the Technical Service Bulletin NHTSA ID: 10252085 (Electrical System, Engine and Engine Cooling); with a similar failure description. The failure mileage was approximately 92,394.
Electrical complaints in other Optima years
Frequently asked questions
How common are electrical problems on the 2015 Kia Optima?
NHTSA has 135 complaints about the electrical system of the 2015 Kia Optima, 13% of the model year's 1,009 complaints. The component named most often is ignition › anti-theft › immobilizer/proximity › key/sender (4 mentions).
Is there a recall for 2015 Kia Optima electrical problems?
No. NHTSA lists no electrical system recall for the 2015 Kia Optima, though it has 4 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2015 Kia Optima electrical problems start?
Half of the complaints with a recorded mileage happened before about 84,000 miles, and 13% before 25,000 miles.
Is it dangerous?
Owners linked 4 crashes, 24 fires and 5 injuries to electrical system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.