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 ↗2016 Kia Optima electrical problems
severe Owners of the 2016 Kia Optima have filed 78 NHTSA complaints about the electrical, typically surfacing around 72,000 miles at roughly $850 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See electrical across all vehicles →
Failure mileage
Complaints
78
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2012 Optima | 95 |
| 2013 Optima | 130 |
| 2014 Optima | 50 |
| 2015 Optima | 104 |
| 2016 Optima (this page) | 78 |
| 2017 Optima | 24 |
| 2018 Optima | 27 |
| 2019 Optima | 18 |
| 2020 Optima | 11 |
3crashes
5fires
1injury
When does it fail?
Of the 78 electrical complaints filed for the 2016 Kia Optima, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 78 electrical complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
No new NHTSA electrical complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
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
Power window regulators are the most chronic complaint: plastic pulleys degrade and destroy entire assemblies, leaving windows stuck down. Owners cite multiple windows failing 3–6 months apart, with repair costs of $500–$3,500 total. Kia refuses warranty coverage, calling it wear and tear despite knowing the problem is widespread.
Headlights cut off randomly while driving at night—forcing hard braking and manual cycling to restore them. Multifunction switches are suspected. One dealership quoted $400 repair and acknowledged the defect.
Engine oil consumption runs excessive (over 1 quart per 1,000 miles), but warning lights don't trigger until oil is critically low. Owners report sudden stalls, loud knocking, and smoke, sometimes requiring full engine replacement. Mechanics confirm this as a known Kia defect.
Electrical gremlins cluster: batteries fail multiple times within months or a year, even after replacement and alternator swaps. Some vehicles lose all power while driving, forcing tows. Two separate fire incidents occurred in parked vehicles at low mileage (10,700 and 29,000 miles), believed electrical in origin.
Hybrid models suffer sudden loss of propulsion mid-highway with "Check Hybrid System" warnings and unresponsive gas pedals. One engine replacement failed the same way within 5,000 miles—dealership allegedly installed ignition coils improperly both times.
Additional electrical failures span cruise control getting stuck in menu mode, rodent damage to soy-based wiring, airbags failing to deploy in crashes, and spark plug failures. Owners report annual electrical repairs across seats, windows, dashboard, and lights with no permanent fixes.
Same Kia Optima electrical reports on nearby years: 2013 · 2014 · 2015 · 2017 · 2018
Failure modes owners describe
Headlight cutoff/random shutdown
Headlights turn off unexpectedly while driving at night, sometimes multiple times, forcing drivers to pull over or brake hard. Owners report the lights come back on only after manual intervention (switch cycling). One dealership cited the multifunction switch as likely cause; another quoted $400 repair.
When: Occurring throughout ownership; incidents reported up to 114k+ miles
Symptoms owners cite: headlights shut off without driver input while driving at night; high beams and low beams shut off randomly; dash displays auto-headlight engagement when it is not activated; lights return only after manual switch cycling
Repairs/costs cited: Dealership quoted $400; multifunction switch suspected by owner research; no confirmed repair cost in narratives
Recalls/TSBs owners mention: Dealership aware and quoted repair but classified as non-recall issue
Power window regulator failure
Window regulator motors and assemblies fail prematurely, causing windows to drop or refuse to operate. Plastic pulleys degrade and destroy the entire regulator. Owners report multiple windows failing in sequence, sometimes all four within months. Kia refuses warranty coverage, classifying as normal wear despite similar complaints across many 2016–2017 Optimas.
When: 2-4 years into ownership; as early as 21k miles; multiple windows failing 3–6 months apart
Symptoms owners cite: window will not roll up or down; window drops suddenly without warning and cannot be raised; windows sag and fall down during driving; regulator gears degrade or break
Repairs/costs cited: Replacement of entire window regulator assembly required (not just plastic pulleys); owners cite $500–$3,500+ repair cost for multiple windows; dealerships note this is a known problem
Recalls/TSBs owners mention: Kia refuses warranty coverage; one recall authorization for rear windows only at one dealership; Kia advised insurance claim for one customer
Battery drain and repeated failures
Multiple battery failures within short timeframes despite replacements and new alternators. Vehicles experience sustained low-voltage conditions, loss of electrical power, and complete shutdown while driving.
When: Throughout ownership; one owner reports three replacements in one year; incidents up to 114k miles
Symptoms owners cite: battery drains without holding charge; vehicle loses power while driving; steering wheel locks up after power loss; electrical system enters emergency mode
Repairs/costs cited: New battery and alternator replacements performed; issue recurs within 20 minutes of test driving in one case
Recalls/TSBs owners mention: No manufacturer response documented
Engine fire/electrical fire
Two separate incidents of vehicle fire. One fire ignited approximately ten minutes after owner exited vehicle while parked in driveway for 15 hours; another occurred while parked in driveway. Both believed to be electrical in origin.
When: One at 10,700 miles; one at 29,000 miles
Symptoms owners cite: flames ignited inside vehicle without warning while parked; vehicle destroyed by fire
Repairs/costs cited: Vehicles destroyed; fire department called and extinguished flames
Recalls/TSBs owners mention: One manufacturer notification made; other incident manufacturer not notified
Hybrid system failure/loss of propulsion
Hybrid Optimas lose power or shift unexpectedly between gas and hybrid engines. Engine stalls, hybrid battery depletes rapidly, and vehicle becomes immobile on highway. Owner reports metallic particles in oil post-failure.
When: One incident at unspecified mileage; another at unspecified current mileage; diagnostic codes appeared 2 weeks before one incident
Symptoms owners cite: strange engine noise and shake; vehicle switches from gas to hybrid engine unexpectedly; hybrid battery depletes within minutes; engine stalls mid-highway; zero propulsion on gas pedal input; check hybrid system warning
Repairs/costs cited: Hybrid battery replacement performed; metallic particles found in oil; dealership slow to schedule appointment
Recalls/TSBs owners mention: None documented
Check hybrid system cutoff
Vehicle randomly stops working while driving on hybrid models, displaying 'HEV: Check Hybrid System. Stop Vehicle and Turn Off Engine' warning. Gas pedal becomes unresponsive, forcing driver to coast to safety. One incident resulted in blown spark plug. Occurs intermittently with no warning.
When: Recurring; one incident 4 years prior followed by safety recall, then recurrence afterward
Symptoms owners cite: vehicle stops working mid-drive without warning; gas pedal stops responding; check hybrid system warning displayed; spark plug blown in one instance; vehicle resumes normal operation a day or two later
Repairs/costs cited: Spark plug replacement required in one case; battery replacement did not resolve issue
Recalls/TSBs owners mention: Previous safety recall issued; issue recurred despite recall completion
Engine stall with no oil warning
Engine stalls while driving with little or no warning from oil-level indicator. Rapid oil consumption (exceeding 1 quart per 1,000 miles) not caught by warning system until engine is nearly dry. Owners report knocking, shaking, and smoke from exhaust. Multiple owners link to known Kia engine defect.
When: Within 30 days of oil change; incidents throughout ownership; one at 57,400 miles
Symptoms owners cite: check engine light flickers before stall; engine shakes and produces loud thudding or knocking noise; smoke from exhaust; oil light does not activate until oil is critically low; engine ceases operation
Repairs/costs cited: Engine replacement required in at least one case (57,400 miles); Valvoline mechanic confirmed high oil consumption issue with these engines
Recalls/TSBs owners mention: One owner emailed dealership with no documented response; replacement engine installed but customer has no assurance defect will not reoccur
Acceleration hesitation and jerking
Vehicle hesitates, stutters, or jerks when accelerating from a stop or during normal driving. Engine performance intermittent, sometimes fine then suddenly resuming. Occurs even on low-mileage vehicles, ruling out normal wear.
When: Low mileage (11,145 miles reported); also reported at 75k+ miles; ongoing for months in some cases
Symptoms owners cite: hesitation or stutter when accelerating from stop; jerking movement during acceleration; delayed throttle response; feels like gear slipping but transmission not at fault
Repairs/costs cited: None documented as completed
Recalls/TSBs owners mention: None documented
Fuel vapor purge valve repeated failure
Purge valve replaced four times in one vehicle; continues to fail. Component malfunction linked to fuel vapor management system defect.
When: Multiple failures throughout ownership; recurrence after each replacement
Symptoms owners cite: fuel vapor management system malfunction; engine performance issues
Repairs/costs cited: Purge valve replaced four times; defect persists
Recalls/TSBs owners mention: None documented
Electronic emergency brake spontaneous engagement
Electronic emergency brake engages unexpectedly while vehicle is in motion, causing sudden deceleration without driver input.
When: At 114,155 miles (reported as ongoing issue)
Symptoms owners cite: electronic emergency brake engages while driving; abrupt deceleration without driver command
Repairs/costs cited: None documented as completed
Recalls/TSBs owners mention: None documented
Airbag and safety system malfunction
Airbags fail to deploy in crash at high speed (60 mph impact); seatbelt does not lock. Vehicle also refuses to shut off after accident, staying operational until EMT manually disconnected power.
When: Incident mileage not specified; cracking reported in airbag area at 4-year ownership mark
Symptoms owners cite: airbags do not deploy in T-bone collision at 60 mph; seatbelt does not lock during impact; vehicle will not shut off after accident; cracking visible in passenger side (near airbag location)
Repairs/costs cited: No repairs documented; heavy chest injuries sustained
Recalls/TSBs owners mention: None documented
Rodent damage to soy-based wiring
Vehicle wiring is soy-based and attracts rodents. Two separate damage incidents totaling approximately $3,000. Kia declined to assist, suggesting insurance claim instead.
When: First incident 11/2019; second incident later in ownership
Symptoms owners cite: rodent damage to vehicle wiring; electrical failures from gnaw marks
Repairs/costs cited: $3,000 total damage across two incidents; owners paid out of pocket on second incident due to insurance concern
Recalls/TSBs owners mention: Kia suggested insurance claim; declined to assist or address soy-based wiring issue
Front camera lens cracking
Front grille camera lens cracks without visible impact or damage to surrounding grille or bumper. Same failure repeated after warranty replacement. Owner found online forum with 3+ pages of similar complaints from other 2016–2017 Optima owners; dealership service manager acknowledged it was unlikely to crack twice without visible damage.
When: First crack in 2017; second crack in August 2018 at 2+ year ownership
Symptoms owners cite: front camera lens cracks; camera produces blurry image; no visible damage to camera unit, grille, or bumper
Repairs/costs cited: First repair covered under warranty (2017); second repair denied as normal wear and tear despite dealership initially agreeing to cover it
Recalls/TSBs owners mention: First replacement covered as warranty item; second denial upheld after consumer contacted Kia Consumer Affairs; service manager acknowledged multiple online complaints but stated uncertainty why not a recall
Cruise control menu malfunction
Cruise control gets stuck in menu display or fails to set. Cannot return to speedometer view without stopping vehicle. Pedal method also fails intermittently. Hazardous while driving as menu blocks speedometer visibility.
When: Ongoing since approximately 75k miles for several months
Symptoms owners cite: cruise control will not set; menu gets stuck and will not return to speedometer; must pull over to reset cruise control; cannot see speedometer while menu is stuck; pedal method to set cruise control sometimes fails
Repairs/costs cited: None documented
Recalls/TSBs owners mention: None documented
Mirror malfunction
Driver-side mirror fails to return to normal position after reverse. Requires returning to reverse and back to drive to reset.
When: Early ownership at 11,145 miles
Symptoms owners cite: mirror does not return to normal position after reverse; mirror stuck in adjusted position
Repairs/costs cited: None documented
Recalls/TSBs owners mention: None documented
Seat warmer button illumination failure
Driver-side seat warmer button does not illuminate correctly. Fewer indicator lights appear on high setting compared to passenger side.
When: Early ownership at 11,145 miles; ongoing for about 2 weeks at time of report
Symptoms owners cite: seat warmer button does not light up properly; high setting only shows 2 lights instead of expected number
Repairs/costs cited: None documented
Recalls/TSBs owners mention: None documented
Moonroof/sunroof rattle noise
Sunroof/moonroof produces loud rattle noise when closed at highway speeds or in windy weather. Kia reset method does not resolve issue. Owner research shows widespread complaints and Kia refusal to repair.
When: Throughout ownership at various speeds
Symptoms owners cite: rattle noise from closed sunroof at highway speeds; rattle noise in windy weather; reset method does not resolve
Repairs/costs cited: None documented; sunroof parts described as expensive
Recalls/TSBs owners mention: Kia does not want to fix according to owner forum research
Running light assembly failure
Driver-side running light fails. Bulb and fuse replacement do not resolve. Power reaches headlight assembly but cuts off before running light connection. Entire headlight assembly replacement required.
When: At unspecified mileage
Symptoms owners cite: driver-side running light will not illuminate; bulb replacement does not fix; fuse replacement does not fix; power loss at headlight assembly connection to running light
Repairs/costs cited: $360 for entire headlight assembly replacement
Recalls/TSBs owners mention: None documented
Engine knock and stall on startup
Loud knocking noise from engine on startup with check engine, oil, and battery warning lights illuminated simultaneously. All four windows also fail to function. Dealership unable to determine cause.
When: At 124,000 miles
Symptoms owners cite: loud knocking noise from engine on startup; check engine light illuminated; oil warning light illuminated; battery warning light illuminated; all four windows fail to operate
Repairs/costs cited: Not repaired at time of report
Recalls/TSBs owners mention: Manufacturer made aware; cause not determined by dealer
Blind spot detection and ABS intermittent malfunction
Blind spot detection warning lights and ABS lights activate. Left rear wheel sensor suspected. Replacement fixes issue temporarily (2 weeks) then lights return. Airbag light remains on after repair.
When: At unspecified mileage
Symptoms owners cite: blind spot detection warning lights on; ABS lights on; airbag light on
Repairs/costs cited: $800 quoted for left rear wheel sensor replacement (no longer under warranty); sensor replaced by independent mechanic; issue recurred after 2 weeks
Recalls/TSBs owners mention: None documented
Engine failure requiring replacement
Engine failure requiring replacement in less than 6 months of ownership. First engine made knocking noise followed by check engine light; owner continued driving as dealer had no immediate appointment. Engine seized within 2 days. Replaced engine then seized again within 5,000 miles. Dealership initially denied responsibility; ignition coils found improperly installed on both engine replacements.
When: First failure early in ownership; second failure within 5,000 miles of first replacement
Symptoms owners cite: loud knocking noise from engine; check engine light flashes; engine seizes; will not start
Repairs/costs cited: Two engine replacements in less than 6 months; ignition coils improperly installed both times; second and third engines exhibiting same symptoms as first
Recalls/TSBs owners mention: Dealership initially refused responsibility for second failure; improper installation noted
Electrical system general malfunction
Chronic electrical issues requiring repair every year affecting various components: windows, dashboard, seats, lighting. Recurring failures across multiple systems without single root cause identified.
When: Throughout 5+ years of ownership
Symptoms owners cite: seat electrical failure; window electrical failure; dashboard electrical issues; lighting failures; pattern of annual electrical repairs
Repairs/costs cited: Multiple repairs each year; no permanent resolution achieved
Recalls/TSBs owners mention: None documented
Headlight bulb frequent burnout
Headlight bulbs fail repeatedly, requiring replacement multiple times within short periods. One owner reports bulb change needed weekly.
When: Over 1-year period; ongoing issue
Symptoms owners cite: headlight bulbs burn out repeatedly; frequent replacement needed
Repairs/costs cited: Bulb replacement; recurring issue
Recalls/TSBs owners mention: None documented
Synthesized from 78 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
All four of my window regulators/and or motors have died within months of each other. First it was my back two, now my front two have gone and don’t stay up. I don’t have children nor frequent passengers. I find it mind boggling that all four of my windows have to be repaired. It is completely unsafe that my windows just drop at any given moment, especially if it’s pouring raining or even at…
First my driver side back window wouldn’t roll up or down. It just sags and falls down everytime I drive so I duck taped it until I could afford to get it fixed. Now a month later, the passenger back seat is doing this exact same thing. There is over 100 articles of people talking about this exact problem with 2016-2017 Kia Optimas and I read apparently Kia is even aware as they sent out an alert…
My oil pressure light continues to turn on and off even after replaced parts! Burning at least 2 quarts of oil per week! Brake lights stop working if headlights are on! Had to start using super to eliminate a rattle while accelerating uphill! Engine shakes!!
Had electrical trouble with your 2016 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 2016 Kia Optima?
It's a meaningful issue. 78 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Across the 32 complaints that reported odometer mileage, most electrical failures cluster between 43,000 and 107,110 miles, with the median around 72,000. A quarter of owners report trouble before 43,000; a quarter make it past 107,110. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
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/2016/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.