P0117 CHEVROLET - Engine Coolant Temperature Circuit Low Input
Low engine coolant level
Faulty Engine Coolant Temperature (ECT) sensor
Faulty engine coolant thermostat
Engine Coolant Temperature (ECT) sensor harness is open or shorted
Engine Coolant Temperature (ECT) sensor circuit poor electrical connection
When is the code detected?
An excessively low voltage from the sensor is sent to ECM.
Engine Light ON (or Service Engine Soon Warning Light)
P0117 Chevrolet Description
The Engine Coolant Temperature (ECT
) sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the Engine Control Module (ECM
). The modified signal returns to the ECM
as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.