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Home >> Infiniti >> 2003 >> G35 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0441: EVAP Control System Incorrect Purge Flow >> Diagnostic Procedure

Diagnostic Procedure

CAUTION: DO NOT use ECM ground terminals when measuring voltage. Damage to ECM transistor may result. Use engine ground.
NOTE: If DTC P0441 is displayed with other DTC such as P0226, P0227, P0228, P1227 or P1228, first perform trouble diagnosis for other DTC.

For component location, see COMPONENT LOCATIONS  . For connector terminal identification, see CONNECTOR IDENTIFICATION  .

  1. Turn ignition off. Inspect EVAP canister for cracks. Replace, if cracked. If EVAP canister is not cracked, and using CONSULT-II, go to next step. If using generic scan tool, go to step  3 .
  2. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port. Connect vacuum gauge to disconnected hose. Start engine and let it idle. Select PURG VOL CONT/V in ACTIVE TEST mode with CONSULT-II. Increase engine speed to 2000 RPM. While observing vacuum gauge, press QD and QU on CONSULT-II screen to adjust PURG VOL CONT/V opening. Vacuum should exist when PURG VOL CONT/V opening is 100 percent. Vacuum should not exist when PURG VOL CONT/V opening is zero percent. If operation is as specified, go to step  7 . If operation is not as specified, go to step  4 .
  3. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port. Connect vacuum gauge to disconnected hose. Start engine and let it idle for at least 80 seconds. While observing vacuum gauge, increase engine speed to 2000 RPM. Vacuum should exist. Release throttle. Vacuum should not exist. If operation is as specified, go to step  8 . If operation is not as specified, go to next step.
  4. Turn ignition off. Check EVAP purge line for blockage or incorrect connections. If problem is found, repair as necessary. If no problem is found, go to next step.
  5. Disconnect purge hoses connected to EVAP service port "A" and EVAP canister purge volume control solenoid valve "B". See Fig 1 . Blow air into each hose and EVAP purge port "C". Ensure air flows freely. If air does not flow freely, repair or clean hoses and/or purge port. If air flows freely, and using CONSULT-II, go to next. If using generic scan tool, go to step  8 .
    Fig 1: Checking EVAP Purge Hose & Purge Port
    G00275835Courtesy of NISSAN MOTOR CO., U.S.A.
  6. Start engine. Perform PURG VOL CONT/V in ACTIVE TEST mode with CONSULT-II. Check that engine speed varies according to the valve opening. If engine speed is correct, go to step  9 . If engine speed is not correct, go to next step.
  7. Disconnect hoses from EVAP canister purge volume control solenoid valve. Command PURG VOL CONT/V to 100 percent with CONSULT-II. Air should flow between EVAP canister purge volume control solenoid valve ports "A" and "B". See Fig 2 . Command PURG VOL CONT/V to zero percent. Air should not flow between EVAP canister purge volume control solenoid valve ports "A" and "B". If operation is as specified, go to step  9 . If operation is not as specified, replace EVAP canister purge volume control solenoid valve.
    Fig 2: Testing EVAP Canister Purge Volume Control Solenoid Valve (With CONSULT-II)
    G00275836Courtesy of NISSAN MOTOR CO., U.S.A.
  8. Turn ignition off. Remove EVAP canister purge volume control solenoid valve. Using jumper wires, apply battery voltage to EVAP canister purge volume control solenoid valve terminals. See Fig 3 . Air should flow between ports "A" and "B". Remove jumper wires. Air should not flow. If operation is as specified, go to next step. If operation is not as specified, replace EVAP canister purge volume control solenoid valve.
    Fig 3: Testing EVAP Canister Purge Volume Control Solenoid Valve (Without CONSULT-II)
    G00275837Courtesy of NISSAN MOTOR CO., U.S.A.
  9. Disconnect EVAP control system pressure sensor harness connector. Check connectors for water. If water exists, repair or replace harness connector. If water does not exist, go to next step.
  10. Check EVAP control system pressure sensor function. See appropriate DTC CONFIRMATION TEST under DTC P0452: EVAP CONTROL SYSTEM PRESSURE SENSOR LOW INPUT  or DTC P0453: EVAP CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT  . If CONFIRMATION TEST is okay, go to next step. If CONFIRMATION TEST is not okay, replace EVAP control system pressure sensor.
  11. Disconnect rubber hose connected to EVAP canister vent control valve. Check hose for blockage. If blockage exists, clean hose with compressed air. If blockage does not exist, go to next step.
  12. Remove EVAP canister vent control valve from EVAP canister. See EVAP CANISTER VENT CONTROL VALVE under EMISSION SYSTEMS & SUB-SYSTEMS in REMOVAL & INSTALLATION - EXCEPT I35 & QX4 article. Check for rust in port "B". See Fig 4 . If rust exists, replace EVAP canister vent control valve. If rust does not exist, and using CONSULT-II, go to next step. If using generic scan tool, go to step  14 .
    Fig 4: Checking EVAP Canister Vent Control Valve
    G00275838Courtesy of NISSAN MOTOR CO., U.S.A.
  13. Turn ignition off. Reconnect harness connectors. Turn ignition on. Perform VENT CONT/V in ACTIVE TEST mode. Check air passage continuity and operation delay time. With VENT CONTROL/V on, air passage continuity between port "A" and port "B" should not exist. With VENT CONT/V off, air passage continuity between port "A" and port "B" should exist and air passage should take less than one second. If EVAP canister vent control valve checks okay, go to step  15 . If EVAP canister vent control valve does not check okay, replace EVAP canister vent control valve.
  14. Check air passage continuity and operation delay time. Apply a 12-volt direct current across EVAP canister vent control valve 2-pin connector (component side). With 12-volt direct current applied, air passage continuity between port "A" and port "B" should not exist. With 12-volt direct current not applied, air passage continuity between port "A" and port "B" should exist. It should take less than one second for valve to open or close. If EVAP canister vent control valve checks okay, go to next step. If EVAP canister vent control valve is does not check okay, replace EVAP canister vent control valve.
  15. Clean the air passage between EVAP canister vent control valve port "A" and port "B" with compressed air. Then, go to next step.
  16. Check EVAP purge line (pipe and rubber hose) for evidence of leaks. If a leak is found, repair as necessary. If no leak is found, go to next step.
  17. Clean EVAP purge line with compressed air. If EVAP purge line is clean, go to next step.
  18. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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