2018 Kia Optima electrical system problems
33 owner complaints filed with NHTSA name the electrical system on the 2018 Kia Optima — 14% of all complaints for this model year.
What owners report
“I am submitting this complaint regarding ongoing and persistent mechanical issues with my vehicle since the time of purchase. The vehicle has repeatedly shut off unexpectedly, creating a serious safety concern. Initially, I suspected the issue might be related to the battery, and I have replaced…”
filed Mar 18, 2026
“I turned the car off, it had difficulty turning back on and the brake pedal got really hard. I had to wait about 30-45 minutes and then I was able to get the car started and brake pedal back to normal and no lights. Recently, I left the car on to run into a shop real quick and come back out. When I…”
filed Jan 8, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
VOLUNTARY EMISSIONS SERVICE CAMPAIGN: OWNER NOTIFICATION (SC340 FLIGHT 104 ) - This document is the owner notification advising that Kia is conducting a Voluntary Emissions Service Campaign to improve the emissions…
SC340_OWNR_JF&JFA_104 · Emissions · issued Mar 17, 2026TECHNICAL SERVICE BULLETIN: VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSION SECM LOGIC IMPROVEMENT (SC340 REV 4) - This bulletin has been revised to include additional information. New/revised sections…
SC340_TSB_R4 · Emissions · issued Mar 6, 2026
Electrical System problems in other Optima years
| Year | Reports | Share |
|---|---|---|
| 2020 Optima | 12 | 9% |
| 2019 Optima | 22 | 11% |
| 2017 Optima | 25 | 10% |
| 2016 Optima | 99 | 13% |
| 2015 Optima | 135 | 13% |
| 2014 Optima | 59 | 10% |
| 2013 Optima | 145 | 11% |
| 2012 Optima | 122 | 13% |
| 2011 Optima | 61 | 10% |
| 2010 Optima | 13 | 17% |
| 2009 Optima | 16 | 14% |
| 2008 Optima | 15 | 10% |
Other reported problem areas on the 2018 Kia Optima
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.