Note. If DTC P0115 and DTC P0116 are output together, ECT sensor circuit may be open. Diagnosis and repair DTC P0115 first. See DTC P0115: ENGINE COOLANT TEMPERATURE (ECT) SENSOR CIRCUIT .
Circuit Description
ECT sensor is a thermistor sensor which monitors water temperature. DTC is set when ECT sensor signal value is out of range during engine operation. Possible causes are
- Defective ECT sensor.
- Defective cooling system.
Diagnostic Aids
After confirming DTC P0116, use scan tool to access CURRENT DATA to confirm engine coolant temperature. If temperature displayed on scan tool is -40°F (-40°C), ECT sensor circuit may be open. If temperature displayed on scan tool is 284°F (140°C) or more, ECT sensor circuit may be shorted. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.