Resistance Inspection

WARNING: This page is about a different car, the 2018 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

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

Fig 1: Placing ECT Sensor In Water With Thermometer
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 .)

Specification (Reference)

RESISTANCE SPECIFICATION

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

Fig 2: ECT Sensor No. 2 Temperature Resistance Graph

Courtesy of MAZDA MOTORS CORP.