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Home >> Mazda >> 2005 >> MX-5 Miata Base, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Coolant Temperature (ECT) Sensor Inspection >> Water Temperature Sender Unit Inspection
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Water Temperature Sender Unit Inspection

  1. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS .) (See ENGINE COOLANT REPLACEMENT .)
  2. Remove the ECT sensor.
  3. Place the sensor in water with a thermometer, and heat the water gradually.
  4. Measure the resistance between ECT sensor terminal C and body GND using an ohmmeter.
    • If not as specified, replace the ECT sensor.

    Specification 

    Water temperature (°C {°F}) Resistance (Ω)
    50 {122} 160-230
    Fig 1: Identifying ETC Sensor Connector
    G03638002Courtesy of MAZDA MOTORS CORP.