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

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 Cylinder head temperature (CHT) sensor concern
Diagnostic Aids: Refer to ENHANCED THERMOSTAT MONITOR for system information.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST DL .