p0128
Easy Fix
Ford · Sedans & Cars
Coolant Thermostat (Coolant Temp Regulation) Malfunction
Quick Answer
Error code P0128 on your Ford Sedans & Cars means: Coolant Thermostat (Coolant Temp Regulation) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Allow engine to cool
2
Check coolant level
3
Monitor temperature gauge
4
Test thermostat operation
5
Replace thermostat if needed
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Thermostat
Coolant (optional)
Gaskets and seals (optional)
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