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 2004 Kia Optima owners, lightly cleaned up (personal details are redacted by NHTSA).
First my passenger side door would not unlock (cannot get the door open at all) - my passengers have to crawl in through the window to sit in passenger seat and my 78 year old grandma can't do that so she has to sit in the back. Now 7 months later, my driver side door will not unlock with the key and when I got off the exit last night doing about 20 or 25 miles an hour, my entire car failed (lcheck engine, brake, oil, etc. Lights all came on and then my car died - total system failure). Towed the car to get checked - nothing wrong with alternator or battery per mechanic. He said Kia knows they have this electrical issue and faulty locks but the cheapskates won't conduct a recall like responsible auto companies do, so he tells all his clients to never buy a Kia. For me, this is a serious safety issue. I saved my money to buy my first car and I have obviously made a poor choice. …
When trying to exit my Kia, the door locks would not unlock. I tried the manual and electrical switches on the door and all I could get was a click, and then an immediate re-lock of the doors, as soon as I pulled on the door handle. I then rolled the window down and tried the key, several times, from the outside with the same results. I managed to work my 79 year old 210 lb. Body over to the passenger seat and tried the same thing and got the same results. I was ready to call 911 when I tried the key on the outside again for the 5th or 6th time and the locks worked. This is a dangerous situation and I understand is quite common on the Kia's at about 100,000 miles, I know I was frightened. I don't know what would happen in a wreck with a fire and the doors would not unlock from the inside or outside. …
The driver side door will not open. It shows that it's unlocked. I can use the key and continuously pull the handle from the outside and it was opening. Now it doesn't work at all. Took it to Kia in holland they quoted me a minimum of $300 to fix the problem but told me they had no clue what it could be. I will not allow an ignorant person to touch my vehicle. I can at least tell you that it is the latch. I live in michigan. If I am hit on my passenger side and am in need of help I might as well close my eyes and die. No one would be able to get me out without having to drag me out of the window which they would have to break. This could easily be an issue that could result in death.
Tl* the contact owns a 2004 Kia Optima. While driving approximately 5 MPH, the vehicle stalled without warning. The vehicle restarted and resumed normal operation. The failure recurred four times and failed to restart on two separate occasions. The vehicle was taken to an independent mechanic, who replaced the fuel pump. The failure persisted after the repair was performed. There was a recall according to NHTSA campaign number: 03V067000 (electrical system) however, the VIN was not included. The vehicle was not repaired. The manufacturer was not notified. The approximate failure mileage was 120,000.
My car completely turns off while im driving it, most of the time when I used it the first time of the day and try to used it again it turns of and loose power, I can't turn it on again in that moment I need to wait and then it works again but if happens really frequently and its really dangerous because im on the freeway and cars are behind me and I can cause an accident or anything worse. I went to the dealership so they could inspect my car but they couldn't find anything at that moment.
Tl* the contact owns a 2004 Kia Optima. The contact stated that the driver side door failed to unlock from outside and inside the vehicle. The contact could not unlock the door manually or with by using the key fob. The vehicle was taken to an authorized dealer who diagnosed that the door actuator switch failed and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 100,000.
Tl* the contact owns a 2004 Kia Optima. The contact stated that the keyless entry ability failed to work for the past three years. The contact mentioned that the rear doors failed to unlock when utilizing a key or manually. The vehicle was not taken to a dealer or an independent mechanic for diagnostic testing. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 87,000.
Accelerated to get out of snow embankment and engine light came on then car locks went out of whack and locked doors. Could not exit, continued to relock and time you touched locks or door to get out! Very unsafe!!! Locked in vehicle only exit rear doors, electrical not OK after reset battery. I ordered new part, not even sure it will fix it. Driver door will not open at all!!!!!!!!!
On several occasions, when manually unlocking the power door locks, they will immediately lock again and will go into a loop of unlock-relock, whether using the manual door lock or the power lock switch (the relay clicks but nothing happens when using the switch). This happens about 10% of the time.
Power door lock locks when unlocking from outside with key. Replaced the door latch. But it still does it. Also the headlights stay on when turning off the car. Have to manually turn off headlight switch.
Electrical complaints in other Optima years
Frequently asked questions
How common are electrical problems on the 2004 Kia Optima?
NHTSA has 45 complaints about the electrical system of the 2004 Kia Optima, 20% of the model year's 225 complaints. The component named most often is horn (1 mentions).
Is there a recall for 2004 Kia Optima electrical problems?
No. NHTSA lists no electrical system recall for the 2004 Kia Optima, though it has 1 recall 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 2004 Kia Optima electrical problems start?
Half of the complaints with a recorded mileage happened before about 85,000 miles, and 14% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 3 fires and 0 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.