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Home >> Ford >> 2000 >> Contour SE, 2.0 3, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 1328 (Engine Controls - Powertrain DTC Charts & Descriptions (Except Diesel & Hybrid)) >> DTC Diagnosis >> DTC P0128: Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

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

WARNING: This page does not describe the selected car, but rather 30 other vehicles, including the 2006 Mercury Mountaineer, 2006 Mercury Monterey, 2006 Mercury Montego, 2006 Mercury Mariner, and 2006 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
P0128 - COOLANT THERMOSTAT (COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE)

Description:  Indicates that 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
  • Inoperative engine coolant temperature (ECT) sensor
  • Inoperative 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 
Vehicles with only a CHT sensor - - GO to Pinpoint Test DL .
All others - - GO to Pinpoint Test DX .