p0128
Moderate
Dodge · Sedans & Muscle Cars
Coolant Thermostat (Coolant Temp Regulating) Malfunction
Quick Answer
Error code P0128 on your Dodge Sedans & Muscle Cars means: Coolant Thermostat (Coolant Temp Regulating) Malfunction. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Monitor coolant temperature at startup
2
Check coolant level and top up if needed
3
Feel radiator hoses for temperature difference
4
Replace thermostat if temperature remains low
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
Gaskets
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