Resistance inspection

Disconnect the negative battery cable. (Refer to NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
Remove the front under cover No. 1. (Refer to FRONT UNDER COVER No. 1 REMOVAL/INSTALLATION .)
Drain the engine coolant. (Refer to ENGINE COOLANT REPLACEMENT .)
Disconnect the ECT sensor No. 2 connector. (Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)
Remove the ECT sensor No. 2. (Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)
Place the ECT sensor No. 2 in water with a thermometer, and heat the water gradually.

Fig 1: Measuring Resistance Between ECT Sensor No. 2 Terminals
Courtesy of MAZDA

Measure the resistance between ECT sensor No. 2 terminals A and B.

If not as specified, replace the ECT sensor No. 2. (Refer to ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)

RESISTANCE SPECIFICATION (REFERENCE)

ECT (°C {°F})	Resistance (Kilohms)
20	Approx. 2.45
80	Approx. 0.318

Fig 2: ECT Temperature And Resistance Graph

Courtesy of MAZDA