P0128 Ford Maverick
Coolant Thermostat Below Regulating Temperature · Powertrain Code · Medium · Repair: Easy
What is P0128?
The engine coolant is not reaching the expected temperature. Most commonly caused by a stuck-open thermostat, low coolant level, or a faulty coolant temperature sensor.
When the Ford Maverick triggers code P0128 (coolant thermostat below regulating temperature), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Ford Maverick.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Ford Maverick.
Common Causes on Ford Maverick
- Thermostat stuck open on 2.0L EcoBoost engine
- Coolant temperature sensor giving inaccurate low-temperature readings
- Low coolant from minor leak at thermostat housing seal
- Thermostat not fully closing due to debris or scale buildup
Symptoms
- Engine takes abnormally long to reach operating temperature
- Heater blows lukewarm or cold air
- Temperature gauge stays below normal or never reaches middle
- Slightly reduced fuel economy from extended open-loop operation
- Check engine light illuminated
Notes for Ford Maverick
Maverick 2.0L EcoBoost thermostat is the same unit used in the Escape platform.