Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (1 Of 5) >> Engine (ECM) >> DTC P0112: IAT Sensor >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

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

      MAF sensor

      Ground

      Voltage (V)

      Connector

      Terminal

      F31

      2

      Ground

      Approx. 5

    Is the inspection result normal?

    YES

    GO TO 2.

    NO

    Repair open circuit, short to ground or short to power in harness or connectors.

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

      MAF sensor

      ECM

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      F31

      1

      F91

      42

      Existed

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

    Is the inspection result normal?

    YES

    GO TO 3.

    NO

    Repair open circuit, short to ground or short to power in harness or connectors.

  3. CHECK INTAKE AIR TEMPERATURE SENSOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Replace mass air flow sensor (with intake air temperature sensor).

  4. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .

    INSPECTION END