P0128 code on 2006 ford escape, solutions?
Diagnostic Test Code (DTC) P0128 has a generic description of "Coolant Temperature Below Thermostat Regulating Temperature".
The Poertrain Control Module (PCM) checks the coolant temperature at startup. It then calculates the period of time that it should take for the engine to reach operating temperature (or thermostat regulated temperature). After the calculated period of time, the PCM again checks the coolant temperature. If it has not reached operating temperature, a code P0128 flag is set in mode 6.
If the engine still has not reached operating temperature after 5 more minutes of continuous engine operation, code P0128 is set in continuous memory and the Check Engine (or Malfunction Indicator Light "MIL" is turned on.
> A stuck-open engine coolant thermostat (MOST common)
> A skewed Engine Coolant Temperature (ECT) or Cylinder Head Temperature(CHT) sensor (working, but not reading correct temperature)
> Low engine coolant level (causing the sensor to not read correctly)
First, the engine coolant (antifreeze) level should be checked. If it is low, it is recommended to perform a cooling system pressure test to find out WHY.
Then, the actual engine temperature should be measured with an infrared thermometer near the ECT or CHT. The reading from the thermometer should be checked against the live sensor data with a scan tool. (PLease note that MOST generic OBD code readers CANNOT perform this function.)
If the reading from the thermometer and the sensor data is within 10 degrees F of each other, replace the thermostat. Otherwise, the sensor circuit should be checked for high resistance (loose or corroded connector, damagd wire, etc.). If no high resistance is measured in the rest of the circuit, the sensor should be replaced.
Jan 03, 2012 |
Ford Escape Cars & Trucks