ECT Sensor No. 2 Inspection

Remove the battery cover. (See BATTERY REMOVAL/INSTALLATION [LF, L5] ).
Disconnect the negative battery cable.
Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS ).
Disconnect the ECT sensor No. 2 connector.
Remove the ECT sensor No. 2. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION ).
Place the ECT sensor No. 2 in water with a thermometer, and heat the water gradually.

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

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

ECT SENSOR NO. 2 SPECIFICATION

ECT (°C {°F})	Resistance (kilohms)
20{68}	Approx. 2.45
80{176}	Approx. 0.318

Fig 1: Identifying ECT Sensor No. 2 Connector Terminals

Courtesy of MAZDA MOTORS CORP.