ECT Sensor No. 1 Inspection

1. Remove the battery cover. (See BATTERY REMOVAL/INSTALLATION [LF, L5] .)
2. Disconnect the negative battery cable.
3. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS .)
4. Remove the battery and battery tray. (See BATTERY REMOVAL/INSTALLATION [LF, L5] .)
5. Disconnect the ECT sensor No. 1 connector.
6. Remove the ECT sensor No. 1. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)
7. Place the ECT sensor No. 1 in water with a thermometer, and heat the water gradually.
8. Measure the resistance between the ECT sensor No. 1 terminals A and B using an ohmmeter.
   • If not as specified, replace the ECT sensor No. 1.

     (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION .)

ECT sensor No. 1 Specification 

Fig 1: Identifying Engine Coolant Temperature (ECT) Sensor Components

Courtesy of MAZDA MOTORS CORP.