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Home >> Infiniti >> 2021 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS) (5 Of 5) >> Engine (ECM) >> DTC P2252: A/F Sensor >> DTC Diagnosis Procedure

DTC Diagnosis Procedure

  1. CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between A/F sensor 1 harness connector and ground.

      A/F sensor 1

      Ground

      Voltage

      Bank

      Connector

      Terminal

      1

      F133

      4

      Ground

      Battery voltage

    Is the inspection result normal?

    YES

    GO TO 3.

    NO

    GO TO 2.

  2. CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector.
    3. Check the continuity between A/F sensor 1 harness connector and IPDM E/R harness connector.

      A/F sensor 1

      IPDM E/R

      Continuity

      Bank

      Connector

      Terminal

      Connector

      Terminal

      1

      F133

      4

      E14

      35

      Existed

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

    Is the inspection result normal?

    YES

    Perform trouble diagnosis for power supply circuit.

    NO

    Repair or replace malfunctioning part.

  3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

      A/F sensor 1

      ECM

      Continuity

      Bank

      Connector

      Terminal

      Connector

      Terminal

      1

      F133

      1

      F92

      79

      Existed

      2

      74

    4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.

      A/F sensor 1

      Ground

      Continuity

      Bank

      Connector

      Terminal

      1

      F133

      1

      Ground

      Not Existed

      2

      ECM

      Ground

      Continuity

      Bank

      Connector

      Terminal

      1

      F92

      74

      Ground

      Not Existed

      79

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

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    Repair or replace malfunctioning part.

  4. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    Repair or replace malfunctioning part.

  5. REPLACE A/F SENSOR 1 

    Replace malfunctioning A/F sensor 1. Refer to EXHAUST MANIFOLD AND THREE WAY CATALYST : Exploded View .

    CAUTION:
    • Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
    • Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).

    INSPECTION END