What does this code mean?
The warm-up performance did not meet the monitor's expectation. Check coolant level only when the engine is cool, compare temperature readings from a cold start, and assess the thermostat and cooling-fan operation. Climate, sensor accuracy and vehicle calibration matter. Never open a hot pressurised cooling system.
Sources and interpretation [1]
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
7Original wording in English
KIA
Reported code forms P0128
TSB: SERVICE ACTION: ECU LOGIC IMPROVEMENT FOR DTC P0128 (SA374) - This bulletin provides the procedure to improve the logic of the Engine Control Unit (ECU) on some 2019MY Rio (SC) vehicles, produced from August 27,…
KIA
Reported code forms P0128
TSB: ECM UPGRADE – RIO, SOUL MIL ON WITH DTC(S) P0456/P0461/P050A/P2188/P2192/P0128/P0326/P0441 - THIS BULLETIN PROVIDES INFORMATION RELATED TO THE ECM SOFTWARE UPGRADE FOR SOME 2012~2014MY RIO (UB), SOME 2012~2013 SOUL…
KIA
Reported code forms P0128
TSB: ECM UPGRADE – RIO, SOUL MIL ON WITH DTC(S) P0456/P0461/P050A/P2188/P2192/P0128/P0326/P0441 - THIS BULLETIN PROVIDES INFORMATION RELATED TO THE ECM SOFTWARE UPGRADE FOR SOME 2012~2013MY RIO (UB) AND SOME 2012~2013…
KIA
Reported code forms P0128
TSB: COMBINED TSB/SERVICE ACTION ? RIO, SOUL 1.6 GDI MIL ON WITH DTCS P0456/P0461/P050A/P2188/P2192/P0128 (SA152) - This bulletin provides information related to the ECM software upgrade for some 2012-2013MY Rio (UB)…
KIA
Reported code forms P0128
KIA: COMBINED TSB/SERVICE ACTION ECM UPGRADE FOR MULTIPLE DTC'S LISTED-P0300, P0128, P0140, P0451, P0461. PROVIDES THE PROCEDURE TO UPGRADE THE ENGINE CONTROL MODULE (ECM) OF SOME VEHICLES (MAP SENSORS ONLY) WHICH MAY…
KIA
Reported code forms P0128
KIA: ECM UPGRADE-MIL ON WITH DTC P0300, P0128, P0140, P0442 & P0461. VEHICLES MAY EXPERIENCE A ROUGH IDLE DURING INITIAL COLD START UP PERIOD AND/OR ILLUMINATE THE MIL. *PE UPDATED 10/29/10. *PE
Check vehicle applicability
8A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Historical vehicle association; OBD-II compatibility is not established by this record.
Historical records · 4 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Sources and interpretation
These explanations are editorial summaries of the linked manufacturer material. PDF page numbers count from the first file page. Original publications are in English; translations are reference aids. A cited edition is not a claim that it is the manufacturer's latest instruction.
- 2024–2025 MY OBD System Operation Summary for Gasoline Engines ↗
Ford Motor Company · PDF page(s) 71 ·
Source check date · 2026-10-27
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.