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Home >> Infiniti >> 2010 >> M45 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0460 To P1421 >> DTC P1421 Cold Start Control >> Diagnosis Procedure
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Diagnosis Procedure

  1. PERFORM IDLE AIR VOLUME LEARNING

    Perform "IDLE AIR VOLUME LEARNING ".

    Is Idle Air Volume Learning carried out successfully? 

    Yes or No 

    Yes: GO TO 2.

    No: Follow the instructions of Idle Air Volume Learning.

  2. CHECK INTAKE SYSTEM

    Check for the cause of intake air volume lacking. Refer to the following.

    • Crushed intake air passage
    • Intake air passage clogging

    OK or NG 

    OK: GO TO 3.

    NG: Repair or replace malfunctioning part.

  3. CHECK FUEL INJECTION SYSTEM FUNCTION

    Perform "DTC CONFIRMATION PROCEDURE " for DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION.

    OK or NG 

    OK: GO TO 4.

    NG: Go to "DIAGNOSIS PROCEDURE ".

  4. PERFORM DTC CONFIRMATION PROCEDURE
    1. Turn ignition switch ON.
    2. Erase DTC.
    3. Perform DTC Confirmation Procedure.

      See "DTC CONFIRMATION PROCEDURE ".

    4. Is the 1st trip DTC P1421 displayed again?

    Yes or No 

    Yes: GO TO 5.

    No: INSPECTION END 

  5. REPLACE ECM
    1. Replace ECM.
    2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs.

      Refer to "ECM RE-COMMUNICATING FUNCTION ".

    3. Perform "VIN REGISTRATION ".
    4. Perform "ACCELERATOR PEDAL RELEASED POSITION LEARNING ".
    5. Perform "THROTTLE VALVE CLOSED POSITION LEARNING ".
    6. Perform "IDLE AIR VOLUME LEARNING ".

    INSPECTION END