Engine Temperature Sensor: Testing and Inspection

ECM Inputs
All of the sensors and input switches can be diagnosed by the use of a "Scan" tool. Following is a short description of how the sensors and switches can be diagnosed by the use of "Scan Tool". The "Scan Tool" can also be used to compare the values for a normal running engine with the engine you"re diagnosing.

Engine Coolant Temperature (ECT) Sensor
A "Scan" tool displays ECT in degree centigrade. After the engine is started, the temperature should rise steadily to about 90°C, Then stabilize when thermostat opens. A fault in the ECT sensor circuit should set a DTC 14 or 15. The DTC charts also contain a chart to check for sensor resistance values relative to temperature.