Checking the engine coolant temperature (ECT) sensor: Notes

Check that the signal from the engine coolant temperature (ECT) sensor is reasonable in comparison with the temperature the engine is considered to be at.

HINT: The comparison should be made both with the engine cold and with the engine at operating temperature. Or at the temperature at which the problem occurs. 

Check the engine coolant temperature (ECT) sensor. Check for contact resistance and oxidation.

Other information: 

• For specifications see Engine coolant temperature (ECT) sensor
• For the signal table, see Signal specification
• To replace the engine coolant temperature (ECT) sensor, see Replacing the thermostat and/or engine coolant temperature sensor
• See Checking wiring and terminals .

Is the engine coolant temperature (ECT) sensor functioning correctly? 

• YES 

  FAULT NOT FOUND:  Troubleshooting has been completed.

• NO 

  Refer to Replacing the engine coolant temperature (ECT) sensor