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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 >> Inspection of Resistance
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Inspection of Resistance

NOTE:
  • Perform the following test only when directed.
  1. Drain the engine coolant. (See COOLING SYSTEM SERVICE WARNINGS .) (See ENGINE COOLANT REPLACEMENT .)
  2. Disconnect the ECT sensor connector.
  3. Remove the ECT sensor.
    Fig 1: Identifying ECT Sensor Connector
    G03637998Courtesy of MAZDA MOTORS CORP.
  4. Place the sensor in water with a thermometer, and heat the water gradually.
    Fig 2: Identifying ECT Sensor Connector Terminals
    G03637999Courtesy of MAZDA MOTORS CORP.
  5. Measure the resistance between the ECT sensor terminals using an ohmmeter.
    • If not as specified, replace the ECT sensor.
    • If ECT sensor is okay, but PID value is out of specification, perform the CIRCUIT OPEN/SHORT INSPECTION .
    Temperature (°C {°F}) Resistance (kilohm)
    20 {68} 2.27-2.74
    80 (176} 0.29-0.34
  6. Reconnect the ECT sensor connector.
    Fig 3: Identifying ECT Sensor Signal Reference Graph
    G03638000Courtesy of MAZDA MOTORS CORP.
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