Resistance Inspection

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G (WITH CYLINDER DEACTIVATION)] .)
Remove the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G (WITH CYLINDER DEACTIVATION)] .)
Place the ECT sensor in water with a thermometer, and heat the water gradually.

Courtesy of MAZDA MOTORS CORP.
Measure the resistance between ECT sensor terminals A and B.
- If not as specified, replace the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [SKYACTIV-G (WITH CYLINDER DEACTIVATION)] .)