LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2019 >> QX50 Essential, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTC/Circuit Diagnosis) (5 Of 12) >> DTC/Circuit Diagnosis >> DTC P0441: EVAP Control System >> Diagnosis Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis Procedure

  1. CHECK EVAP CANISTER 
    1. Turn ignition switch OFF.
    2. Check EVAP canister for cracks.

    Is the inspection result normal?

    YES

    With CONSULT: GO TO 2 .

    YES

    Without CONSULT: GO TO 3 .

    NO

    Replace EVAP canister. Refer to Removal and Installation .

  2. CHECK PURGE FLOW 

    SYMBOL With CONSULT

    1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port. Refer to Exploded View .
    2. Start the engine and let it idle.
    3. Select "PURG VOL CONT/V" in "ACTIVE TEST" mode of "ENGINE" using CONSULT.
    4. Touch "Qd" and "Qu" on CONSULT screen to adjust "PURG VOL CONT/V" opening and check vacuum existence.

      PURG VOL CONT/V

      Vacuum

      100%

      Existed

      0%

      Not existed

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    GO TO 4.

  3. CHECK PURGE FLOW 

    SYMBOL Without CONSULT

    1. Start the engine and warm it up to normal operating temperature.
    2. Stop the engine.
    3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port and install vacuum gauge. Refer to Exploded View .
    4. Start engine and let it idle.

      Never depress accelerator pedal even slightly.

    5. Check vacuum gauge indication before 60 seconds pass after starting engine.

      Vacuum should not exist.

    6. Rev engine up to 2, 000 rpm after 100 seconds pass after starting engine.

      Vacuum should exist.

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    GO TO 4.

  4. CHECK EVAP PURGE LINE 
    1. Turn ignition switch OFF.
    2. Check EVAP purge line for improper connection or disconnection. Refer to System Description .

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    Repair EVAP purge line.

  5. CHECK EVAP PURGE HOSE AND PURGE PORT 
    1. Disconnect purge hoses connected to EVAP service port SYMBOL and EVAP canister purge volume control solenoid valve SYMBOL .
      G04074089Courtesy of NISSAN NORTH AMERICA, INC.
    2. Blow air into each hose and EVAP purge port SYMBOL .
    3. Check that air flows freely.
      G04074090Courtesy of NISSAN NORTH AMERICA, INC.

    Is the inspection result normal?

    YES

    With CONSULT: GO TO 6 .

    YES

    Without CONSULT: GO TO 7 .

    NO

    Repair or clean hoses and/or purge port.

  6. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE 

    SYMBOL With CONSULT

    1. Start the engine.
    2. Perform "PURG VOL CONT/V" in "ACTIVE TEST" mode of "ENGINE" using CONSULT. Check that engine speed varies according to the valve opening.

    Does engine speed vary according to the valve opening?

    YES

    GO TO 8.

    NO

    GO TO 7.

  7. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE 

    Check the EVAP canister purge volume control solenoid valve. Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 8.

    NO

    Replace EVAP canister purge volume control solenoid valve. Refer to Exploded View .

  8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR 
    1. Disconnect EVAP control system pressure sensor harness connector.
    2. Check that water is not inside connectors.

    Is the inspection result normal?

    YES

    GO TO 9.

    NO

    Replace EVAP control system pressure sensor. Refer to Exploded View .

  9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR FUNCTION 

    Refer to DTC Description for DTC P0452, DTC Description for DTC P0453.

    Is the inspection result normal?

    YES

    GO TO 10.

    NO

    Replace EVAP control system pressure sensor. Refer to Exploded View .

  10. CHECK RUBBER TUBE FOR CLOGGING 
    1. Disconnect rubber tube connected to EVAP canister vent control valve.
    2. Check the rubber tube for clogging.

    Is the inspection result normal?

    YES

    GO TO 11.

    NO

    Clean the rubber tube using an air blower.

  11. CHECK EVAP CANISTER VENT CONTROL VALVE 

    Check the EVAP canister vent control valve. Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 12.

    NO

    Replace EVAP canister vent control valve. Refer to Exploded View .

  12. CHECK EVAP PURGE LINE 

    Inspect EVAP purge line (pipe and rubber tube). Check for evidence of leaks.

    Is the inspection result normal?

    YES

    GO TO 13.

    NO

    Repair or replace malfunctioning part.

  13. CLEAN EVAP PURGE LINE 

    Clean EVAP purge line (pipe and rubber tube) using air blower.

    INSPECTION END