Ignition switch, key fob or immobilizer failure on the 2005 Kia Optima
Only 5 reports for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.
When ignition switch, key fob or immobilizer failure gets reported
There are 6 reports of ignition switch, key fob or immobilizer failure on the 2005 Kia Optima, 5 with a mileage attached. That is too few to place the failure on the odometer with any confidence.
A part like this is normally expected to survive 85,000 miles. It is the 6th most-reported problem on this model year.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| — | — | 100,050 miles | — | — |
Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.
What a percentile can and cannot tell you here
These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.
What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.
Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.
What happens, and what it costs
Putting it right typically runs $250–$1,500 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.
The same failure on other years
The same failure is reported on 13 model years of this car. It shows up earliest on the 2006, at a median of 50,000 miles, and latest on the 2004 at 115,000 miles.
By volume the 2006 carries the most reports, with 16; the 2005 has 6. A mode that appears across most years of a model is usually a design choice rather than a bad batch.
If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.
Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens
What owners wrote
Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.
Reporting a failure in the door lock mechanism. The door lock will "unlock" when you push the button on the key fob, door panel or use the key to unlock the door. When you pull the handle to open the door, it locks the door preventing you from opening it. The driver is trapt in the car with the only option to exit from the passenger side. This would be a serious safety issue in the event of an accident or any other time you needed to evacuate the car quickly. In searching the internet there are numerous reports of this problem on kia vehicles. *tt
Tl* the contact owns a 2005 kia optima. The contact stated that the front doors did not open when using the key, key fob, or from the interior. The contact had to enter the vehicle from the rear. The vehicle had not been taken to the dealer. The failure mileage was 73,000 and the current mileage was 75,000. The VIN was not accepted.
Tl* the contact owns a 2005 kia optima. While parked, the contact attempted to unlock the front driver side door but it would not unlock. The contact entered the vehicle through the front passenger side door. The front driver side door would not unlock using the key fob from the exterior or manually from the interior or exterior of the vehicle. The vehicle was not taken to the dealer for diagnostics. The dealer was made aware of the failure and advised the contact that the key fob and door locks would have to be replaced . The vehicle was not repaired. The approximate failure mileage was 65,000.
Also reported on the 2005 Kia Optima
Other body or interior problem
Door latch or handle failure
Other electrical problem
Airbag warning light or occupant sensor fault
Fuel tank, filler or EVAP failure
Seat belt or retractor failure
How far this goes
This page is kept out of search results because 6 reports is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.
Complaints are voluntary, so 6 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.
Questions this page answers
At what mileage does ignition switch, key fob or immobilizer failure happen on the 2005 Kia Optima?
Across 5 owner reports that included an odometer reading, half were filed by 100,000 miles. A quarter were filed before — and a quarter after —. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is ignition switch, key fob or immobilizer failure on the 2005 Kia Optima?
6 reports have been filed with NHTSA, about 0.2 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.
What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars
Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed