DTC P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2013 Lincoln Navigator, 2013 Lincoln MKZ, 2013 Lincoln MKX, 2013 Lincoln MKT, and 2013 Lincoln MKS. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0128: COOLANT THERMOSTAT (COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE)

Description:	Indicates the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine.
Possible Causes:	Insufficient warm up time Low engine coolant level Leaking or stuck open thermostat Damaged engine coolant temperature (ECT) sensor Damaged cylinder head temperature (CHT) sensor
Diagnostic Aids:	Refer to THERMOSTAT MONITOR for system information.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
Edge 2.0L, Escape 2.0L, Explorer 2.0L, Fiesta, Focus, Fusion 1.6L, Fusion 2.0L, MKT 2.0L, MKZ 2.0L, Taurus 2.0L	GO to PINPOINT TEST DX .
All others	GO to PINPOINT TEST DL .