Service bulletins for the 2025 Kia K4
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
19 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
Only bulletins with component: Engine are shown. Show all
| OTA_SA621 | 2025-12-10. Over-the-air update. ENGINE; ELECTRICAL SYSTEM. RELEASE NOTES: OVER-THE-AIR: SERVICE ACTION SOFTWARE UPDATE FOR WARNING LIGHTS (SA621) - This Over-the-Air (OTA) software update is designed to update the Engine Control Unit (ECU) logic of certain 2025 K4 vehicles. This update improves the processing logic of the Engine Control Unit (ECU) to reduce the unintended display of warning lights. |
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| TSB_ENG258 | 2025-09-23. Service bulletin. ENGINE. 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. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.