Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

A scan tool displays engine coolant temperature in degrees (Celsius & Fahrenheit). After engine is started, the temperature should rise steadily to about 90°C (194°F) then stabilize when thermostat opens.

Diagnostic Trouble Code (DTC) 14 or DTC 15 indicates a failure in Engine Coolant Temperature (ECT) sensor circuit. The DTC charts also contain a chart to check for ECT sensor resistance values relative to temperature. Refer to Diagnostic Trouble Code Charts/Diagnostic Charts. Testing and Inspection