p0128
Moderate
Kia · SUVs
Coolant Thermostat (Coolant Temp Regulation) Malfunction
Quick Answer
Error code P0128 on your Kia SUVs means: Coolant Thermostat (Coolant Temp Regulation) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Faulty thermostat
  2. Coolant temperature sensor defect
  3. Water pump failure
  4. Cooling fan malfunction
  5. Radiator blockage
How to Fix It
1
Monitor coolant temperature on scanner
2
Check radiator coolant level
3
Test thermostat operation
4
Inspect water pump function
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Thermostat
Coolant
Water pump gasket
Related Error Codes
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