NHTSA Service Bulletin 11023283: 2025 Kia K4
Official manufacturer communication context for 2025 Kia K4, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.
Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.
TECHNICAL SERVICE BULLETIN: SERVICE ACTION: ECM JUDGEMENT LOGIC IMPROVEMENT FOR DTC P218100 (SA621) - This bulletin provides information to upgrade the Engine Control Module (ECM) system software on certain 2025MY K4 (CL4m) vehicles produced from July 03, 2024 through April 28, 2025 equipped with an Nu 2.0L MPI engine. The vehicles affected may exhibit a MIL ON with DTC P218100 stored under certain driving conditions such as high-load, high-speed driving in low temperature environments. There are no drivability or other symptoms associated with this condition. High-load control logic helps to lower the coolant temperature by allowing the valve of the Integrated Thermal Module (ITM) to fully open the radiator port during rapid acceleration.
What this bulletin may mean before buying
Treat this as service research, not a verdict on one car. Before you buy, compare this communication with official recall campaigns, model-level owner complaint patterns, and the exact vehicle’s VIN-decoded specifications. A bulletin can help you ask a seller or dealer sharper questions about software updates, known repairs, warranty extensions and service history.
Affected products listed in this communication
Buyer checklist
- Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
- Check recall campaign pages for safety actions that may require dealer repair.
- Compare this bulletin with common problem pages for the same model and component area.
- Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
- Use the used-car buying checklist and get an independent inspection.
Frequently asked questions
What is NHTSA service bulletin 11023283?
TECHNICAL SERVICE BULLETIN: SERVICE ACTION: ECM JUDGEMENT LOGIC IMPROVEMENT FOR DTC P218100 (SA621) - This bulletin provides information to upgrade the Engine Control Module (ECM) system software on certain 2025MY K4 (CL4m) vehicles produced from July 03, 2024 through April 28, 2025 equipped with an Nu 2.0L MPI engine. The vehicles affected may exhibit a MIL ON with DTC P218100 stored under certain driving.
Is a service bulletin the same as a recall?
No. A recall is a safety campaign with a required remedy for affected VINs. A service bulletin or manufacturer communication usually describes diagnostic, repair, software, warranty or service information.
How should a used-car buyer use this bulletin?
Use it as a research signal. Compare it with recalls, owner complaints, service records, a VIN report and an independent inspection before buying.
Check the exact VIN before you buy
Model-level pages show public safety patterns. A full VIN report helps confirm the exact vehicle, decoded specs, recall applicability and buyer checks.
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