p0128
Easy Fix
Ford · SUVs
Coolant Thermostat Below Regulating Temperature
Quick Answer
Error code P0128 on your Ford SUVs means: Coolant Thermostat Below Regulating Temperature. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
BRNCOBRNCSEDGEESCPEEXPDNEXPLREXPLRHBronco Badlands 2024Bronco Base 2024Bronco Big Bend 2024Bronco Raptor 2024Bronco Sport Badlands 2024Bronco Sport Base 2024Bronco Sport Big Bend 2024Bronco Wildtrak 2024Escape Active 2024Escape Platinum 2024Escape ST-Line 2024Expedition King Ranch 2024Expedition Limited 2024Expedition Platinum 2024Expedition XLT 2024Explorer Base 2024Explorer Limited 2024Explorer Platinum 2024Explorer ST 2024Explorer XLT 2024MACHE
Likely Causes
How to Fix It
1
Check coolant level and top off if low
2
Monitor engine coolant temperature with a scan tool during warm-up
3
Compare ECT sensor reading to an infrared thermometer reading on the thermostat housing
4
Replace the thermostat if the engine does not reach operating temperature within the expected time
5
Replace ECT sensor if readings are inaccurate compared to actual temperature
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
Thermostat housing gasket
Engine coolant temperature sensor
Coolant
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