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 software logic in the Electronic Control Module (ECM) for certain 2016-2020 MY Optima vehicles equipped with 2.4L Gas Direct Injection (GDI) engines to ensure compliance with emissions regulations.
full bulletin at NHTSA ↗2020 Kia Optima electrical problems
severe Owners of the 2020 Kia Optima have filed 11 NHTSA complaints about the electrical at roughly $850 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See electrical across all vehicles →
Complaints
11
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2016 Optima | 78 |
| 2017 Optima | 24 |
| 2018 Optima | 27 |
| 2019 Optima | 18 |
| 2020 Optima (this page) | 11 |
1fire
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering electrical on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
TECHNICAL 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 of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to upgrade the Electronic Control Module ‘ECM’ system software for certain 2016-2022MY vehicles equipped with 2.4L Theta II engines listed in the table below. Kia has become aware that certain 2016-2022MY vehicles equipped with 2.4L Theta II engines may have engine calibrations that were not optimized for emissions standards under certain specific conditions. These calibrations
full bulletin at NHTSA ↗VOLUNTARY EMISSIONS SERVICE CAMPAIGN: DEALER PRINCIPAL MEMO (SC340) - This document is the announcement to the dealer principals advising that Kia is conducting a Voluntary Emissions Service Campaign to improve the emissions software logic in the Electronic Control Module (ECM) to ensure compliance with emissions regulations in certain 2017-2022 MY Sportage vehicles manufactured from December 10, 2015, through December 7, 2021, certain 2016-2020 MY Optima vehicles manufactured from August 28, 2015, through June 23, 2020, and certain 2016-2020 MY Sorento vehicles manufactured from October 27, 2014, through November 4, 2020, equipped with 2.4L Theta GDI engines.
full bulletin at NHTSA ↗VOLUNTARY EMISSIONS SERVICE CAMPAIGN: DEALER PARTS AND SERVICE MANAGER MEMO (SC340) - This document is the announcement to the dealer Parts and Service managers advising that Kia is conducting a Voluntary Emissions Service Campaign to improve the emissions software logic in the Electronic Control Module (ECM) to ensure compliance with emissions regulations in certain 2017-2022 MY Sportage vehicles manufactured from December 10, 2015, through December 7, 2021, certain 2016-2020 MY Optima vehicles manufactured from August 28, 2015, through June 23, 2020, and certain 2016-2020 MY Sorento vehicles manufactured from October 27, 2014, through November 4, 2020, equipped with 2.4L Theta GDI engines.
full bulletin at NHTSA ↗VOLUNTARY EMISSIONS SERVICE CAMPAIGN: SC340_POC: PROOF OF CORRECTION CARD
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2020 Kia Optimas describe a cluster of electrical and engine problems that Kia hasn't adequately addressed. The knock sensor fault (P1326 code) causes the check engine light to flash and forces the vehicle into limp mode, dropping speed from highway cruising (75 mph) to 32-63 mph with no ability to accelerate further. This happens sporadically, sometimes triggered by heavy rain or car washes. Owners have paid out of pocket to replace knock sensors multiple times.
More severe are reports of catastrophic engine failure. Several owners describe excessive oil consumption (2 quarts per 1000 miles), engine seizure, and in one case, a fire under the hood. One owner was stranded multiple times, and another found the dealership refused to file warranty paperwork despite having documented proof of the oil burn. Kia has denied claims citing expired warranties or second-owner status.
The anti-theft vulnerability is documented: vehicles start with a USB charger or flathead screwdriver—no key or fob needed. Multiple thefts have been reported, learned and spread via TikTok. Owners say dealerships never mentioned a required anti-theft software upgrade at purchase. Insurance companies have denied claims because this defect is now widely known.
Headlight electrical shorts are also reported, with bulbs and assemblies failing repeatedly since 2020.
Same Kia Optima electrical reports on nearby years: 2017 · 2018 · 2019
Failure modes owners describe
Knock sensor fault / limp mode
Check engine light flashes, car enters limp mode (power reduction), unable to accelerate beyond 32-63 mph. Code P1326 reported. Owners report this occurs sporadically, sometimes after hard rain or car wash.
When: Various; one at 60k miles, another at 75 mph highway, another after heavy rain/car wash
Symptoms owners cite: Flashing check engine light; Knocking sound from engine; Abrupt power loss while driving (75 mph drops to 32-63 mph); Vehicle enters limp mode; Cannot accelerate past reduced speed
Codes mentioned: P1326, Code 1326
Repairs/costs cited: Knock sensor replacement required. Owners paid for replacement at independent mechanic and Kia dealership.
Recalls/TSBs owners mention: Recall exists for model years older than 2020. Kia informed owner they lack sufficient complaint volume to investigate 2020 model. No TSB or warranty coverage mentioned for 2020s.
Engine bearing/internal failure with excessive oil consumption
Engine consumes 2 quarts per 1000 miles, vehicle dies while driving with flashing check engine and oil lights. Internal engine damage reported by independent mechanic. Owners stranded multiple times requiring oil top-ups. One vehicle caught fire under the hood.
When: Around 60k miles; one owner reports starting September 2023 at 60k, another at 105k miles
Symptoms owners cite: Excessive oil consumption (2 quarts per 1000 miles); Flashing check engine light; Flashing oil light; Engine dies while driving; Rumbling noise on restart attempt; Engine will not stay running; Smoke and fire under hood
Repairs/costs cited: Estimated engine replacement cost $10,000+. One owner went through warranty process 3x over one year; dealership refused to file warranty paperwork. Engine fire damage also reported.
Recalls/TSBs owners mention: Warranty expired at 60k miles on one vehicle; extended warranty denied on second owner (105k miles). Dealership refused to honor warranty despite clear documentation of oil burn.
Vulnerability to theft / weak immobilizer
2020 Kia Optimas are easily stolen using a USB cord/charger block or flathead screwdriver without key or fob. Multiple thefts reported; method shared on social media (TikTok). Anti-theft software upgrade available but owners not notified by dealership or Kia at point of sale.
When: Multiple incidents: July 2022, April 2023, ongoing
Symptoms owners cite: Vehicle starts without key or fob using USB cord; Vehicle starts without key or fob using flathead screwdriver; No warning or immobilizer activation
Repairs/costs cited: Theft damage costs over $4000 in one case. Owners requesting immobilizer installation to obtain insurance.
Recalls/TSBs owners mention: No notification at dealership or from Kia about required anti-theft software upgrade. No recall issued. Insurance denied one claim citing known defect.
Headlight electrical shorts
Both front headlights short out simultaneously while driving without warning. Bulbs and entire headlight assemblies replaced multiple times since 2020 with recurring failure.
When: Ongoing since 2020; multiple failures through current date
Symptoms owners cite: Both headlights short out simultaneously; Lights flicker or don't come on; No warning prior to failure
Repairs/costs cited: Headlight bulbs replaced 4 times, headlight assemblies replaced 3 times over vehicle lifespan.
Vehicle self-locks while running with no occupant
Vehicle locks by itself while engine is running and no one is inside the car. Isolated report but indicates electrical/locking system malfunction.
When: Frequency not specified
Symptoms owners cite: Door locks engage while vehicle running and unoccupied
Radio/infotainment system failure
Dashboard screen where radio displays goes blank intermittently.
When: Frequency not specified
Symptoms owners cite: Infotainment screen goes blank
Synthesized from 11 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had electrical trouble with your 2020 Kia Optima?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the electrical problem on the 2020 Kia Optima?
It's a meaningful issue. 11 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2020/Kia/Optima.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.