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Home >> Infiniti >> 2021 >> Q50 Pure, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 6) >> Engine (ECM) >> DTC P0118: ECT Sensor >> DTC Diagnosis Procedure >> VR30DDTT engine

VR30DDTT engine

  1. CHECK ECT SENSOR 1 POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect engine coolant temperature (ECT) sensor 1 harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between ECT sensor 1 harness connector and ground.

      ECT sensor 1

      Ground

      Voltage

      (Approx.)

      Connector

      Terminal

      F86

      1

      Ground

      5 V

    Is the inspection result normal?

    YES

    GO TO 3.

    NO

    GO TO 2.

  2. CHECK ECT SENSOR 1 POWER SUPPLY CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between ECT sensor 1 harness connector and ECM harness connector.

      ECT sensor 1

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F86

      1

      F143

      48

      Existed

    4. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES

    Perform trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

    NO

    Repair or replace error-detected parts.

  3. CHECK ECT SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between ECT sensor 1 harness connector and ECM harness connector.

      ECT sensor 1

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F86

      2

      F143

      29

      Existed

    4. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Repair or replace error-detected parts.

  4. CHECK ECM GROUND CIRCUIT 
    1. Check the continuity between ECM harness connector and ground.

      +

      -

      Continuity

      ECM

      Connector

      Terminal

      F143

      3

      Ground

      Existed

      F142

      87

      88

      E152

      199

      201

      204

    2. Also check harness for short to power.

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    Repair or replace error-detected parts.

  5. CHECK ENGINE COOLANT TEMPERATURE SENSOR 1 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    Replace engine coolant temperature sensor 1. Refer to MULTI-WAY CONTROL VALVE : Exploded View .