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Manufacturer communication · Emissions

Kia bulletin SC340

Kia filed this with NHTSA as a emissions communication dated Apr 4, 2026, received Oct 24, 2025, about the engine — 20 documents under this number: SC340_TSB_R5, SC340_OWNR_NQ5_105, SC340_OWNR_JF&JFA_104, SC340_TSB_R4 and more. It names 17 model years (2016–2022). A emissions communication is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.

What the bulletin says

Source: NHTSA's summary of the manufacturer's communication

VOLUNTARY EMISSIONS SERVICE CAMPAIGN: THETA II 2.4L GDI EMISSIONS: ECM LOGIC IMPROVEMENT (SC340 REVISION 5) - 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 2016-2020MY Optima, 2016-2020MY Sorento, 2017-2022MY Sportage 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 may cause the vehicle to release air pollutants which exceed Federal and California standards. These standards were established to protect your health and welfare from the dangers of air pollution.

Manufacturer campaign id SC340 Kind Emissions (also filed as Service bulletin) Manufacturer date Apr 4, 2026 Received by NHTSA Oct 24, 2025 Components Engine, Electrical System First dated Oct 23, 2025

Documents filed under this number

DocumentKindDatedNHTSA idAt NHTSA
SC340_TSB_R5EmissionsApr 4, 202611031854not yet checked
SC340_OWNR_NQ5_105EmissionsMar 17, 202611030391not yet checked
SC340_OWNR_JF&JFA_104EmissionsMar 17, 202611030390not yet checked
SC340_TSB_R4EmissionsMar 6, 202611029979not yet checked
SC340_OWNR_UM103EmissionsDec 19, 202511026900not yet checked
SC340_OWNR_JF103EmissionsDec 19, 202511026899not yet checked
SC340_OWNR_QL103EmissionsDec 19, 202511026898not yet checked
SC340_TSB_R3Service bulletinDec 10, 202511026533not yet checked
SC340_OWNR_JF101EmissionsNov 27, 202511025897not yet checked
SC340_OWNR_QL101EmissionsNov 27, 202511025895not yet checked
SC340_OWNR_UM101EmissionsNov 27, 202511025894not yet checked
SC340_TSB_R2Service bulletinNov 21, 202511025892not yet checked
SC340_OWNR_JF102EmissionsNov 7, 202511025898not yet checked
SC340_TSB_R1Service bulletinNov 7, 202511025859not yet checked
SC340_TSBService bulletinNov 5, 202511025889not yet checked
SC340_STKREmissionsOct 23, 202511024469not yet checked
SC340_QAEmissionsOct 23, 202511024468not yet checked
SC340_POCEmissionsOct 23, 202511024467not yet checked
SC340_DPSMEmissionsOct 23, 202511024462not yet checked
SC340_DPEmissionsOct 23, 202511024445not yet checked

The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.

Model years it names

Source: as the manufacturer filed them

A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.

Common questions

Source: NHTSA, 49 CFR 579.5

Is Kia SC340 a recall?

No. A emissions communication is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.

Is the SC340 repair free?

A emissions communication is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.

Which vehicles does SC340 cover?

The manufacturer filed it against 17 model years: 2020 Kia Optima, 2019 Kia Optima, 2018 Kia Optima, 2017 Kia Optima, 2016 Kia Optima, 2020 Kia Sorento and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.