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Home >> Infiniti >> 2021 >> Q60 Pure, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 7) >> Engine (ECM) >> DTC P0112: IAT Sensor >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

  1. CHECK INTAKE AIR TEMPERATURE SENSOR 1 POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect mass air flow (MAF) sensor (intake air temperature sensor 1 is built-into) harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between mass air flow sensor (bank 1) harness connector and ground.

      +

      -

      Voltage

      (Approx.)

      MAF sensor (bank 1)

      Connector

      Terminal

      F99

      4

      Ground

      5 V

    Is the inspection result normal?

    YES

    GO TO 3.

    NO

    GO TO 2.

  2. CHECK INTAKE AIR TEMPERATURE SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between mass air flow sensor (bank 1) harness connector and ECM harness connector.

      MAF sensor (bank 1)

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F99

      4

      F143

      43

      Existed

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

    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 INTAKE AIR TEMPERATURE SENSOR 1 GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between mass air flow sensor (bank 1) harness connector and ECM harness connector.

      MAF sensor (bank 1)

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F99

      3

      F143

      30

      Existed

    4. Also check harness for 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.

      ECM

      --

      Continuity

      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 INTAKE AIR TEMPERATURE SENSOR 1 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    INSPECTION END.

    NO

    Replace mass air flow sensor (bank 1) (with intake air temperature sensor 1). Refer to AIR CLEANER AND AIR DUCT : Exploded View .