Resistance Inspection

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Drain the engine coolant. (See Engine Coolant Replacement .)
Remove the ECT sensor No. 1. (See Engine Coolant Temperature (ECT) Sensor Removal/Installation .)
Place the ECT sensor No. 1 in water with a thermometer, and heat the water gradually.

Fig 1: Measuring Resistance Between ECT Sensor No. 1 Terminals A And B And Connector End View
Courtesy of MAZDA MOTORS CORP.
Measure the resistance between ECT sensor No. 1 terminals A and B.
- If not as specified, replace the ECT sensor No. 1. (See Engine Coolant Temperature (ECT) Sensor Removal/Installation .)