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Home >> Acura >> 2004 >> TL Standard >> Repair and Diagnosis >> Engine Mechanical >> Auxiliary Emission Control Systems >> EVAP System >> DTC Troubleshooting >> DTC P0497: EVAP System Low Purge Flow

DTC P0497: EVAP System Low Purge Flow

Special Tools Required 

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Check the fuel fill cap (the cap must say "Tighten to click"). It should turn 1/4 turn after it's tight, then it clicks.

    Is the correct fuel fill cap installed and properly tightened? 

    1. YES  - Go to step  2.
    2. NO  - Replace or tighten the fuel fill cap, then go to step  24.
  2. Turn the ignition switch ON (II).
  3. Clear the DTC with the HDS.
  4. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

    Is the result OK? 

    1. YES  -Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, or the EVAP canister vent shut valve and the ECM/PCM.
    2. NO  - Go to step  5.
  5. Check for a loose or damaged EVAP canister purge line between the intake manifold and the EVAP canister purge valve.

    Is the line OK? 

    1. YES  - Go to step  6.
    2. NO  - Reconnect or repair the EVAP canister purge line, then go to step  24.
  6. Disconnect the vacuum hose from the EVAP canister purge valve service port (A) in the engine compartment, and connect a T-fitting (B) from the vacuum gauge and the vacuum pump/gauge, 0-30 in.Hg, to the vacuum hose (C) as shown.
    Fig 1: Disconnecting Vacuum Hose From EVAP Canister Purge Valve
    G03659880Courtesy of AMERICAN HONDA MOTOR CO., INC.
  7. Select EVAP PCS ON in the INSPECTION MENU with the HDS.
  8. Slowly apply about 2.0 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.

    Does it hold vacuum? 

    1. YES  - Replace the EVAP canister purge valve, then go to step  24.
    2. NO  - Go to step  9.
  9. Reconnect the vacuum hose to the EVAP service port.
  10. Disconnect the vacuum hose from the EVAP canister purge line (at the EVAP canister side), and connect a T-fitting (A) from the vacuum gauge and the vacuum pump/gauge, 0-30 in.Hg, to the hose as shown.
    Fig 2: Disconnecting Vacuum Hose From EVAP Canister Purge Line
    G03659881Courtesy of AMERICAN HONDA MOTOR CO., INC.
  11. Select EVAP PCS ON in the INSPECTION MENU with the HDS.
  12. Slowly apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.

    Does it hold vacuum? 

    1. YES  - Check for a restricted EVAP canister purge line between the EVAP canister purge valve and the EVAP canister, then go to step  23.
    2. NO  - Go to step  13.
  13. Remove the FTP sensor with its connector connected (see FTP SENSOR REPLACEMENT ).
  14. Connect a T-fitting (A) from the vacuum pump/gauge, 0-30 in.Hg, and the vacuum pressure gauge 0-4 in.Hg (0-100 mmHg) to the FTP sensor (B) as shown.
    Fig 3: Connecting T-Fitting
    G03659882Courtesy of AMERICAN HONDA MOTOR CO., INC.
  15. Check and record the FTP SENSOR reading in the DATA LIST with the HDS.
  16. Slowly apply about 1.3 kPa (0.4 in.Hg, 10 mmHg) of vacuum to the hose.
  17. Check the FTP SENSOR in the DATA LIST with the HDS.

    Is the difference more than 1.1 kPa (0.31 in.Hg, 8 mmHg) before and after applying vacuum? 

    1. YES  - Go to step  18.
    2. NO  - Replace the FTP sensor (see FTP SENSOR REPLACEMENT  ), then go to step  23.
  18. Reconnect the vacuum hoses to the EVAP canister purge line (EVAP canister side), and reinstall the FTP sensor.
  19. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B), and connect a T-fitting (C) from the vacuum gauge and the vacuum pump/gauge, 0-30 in.Hg, to the hose as shown.
    Fig 4: Disconnecting Vacuum Hose From EVAP Canister Purge Valve
    G03659883Courtesy of AMERICAN HONDA MOTOR CO., INC.
  20. Select EVAP CVS ON in the INSPECTION MENU with the HDS.
  21. Slowly apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.

    Does the hose hold vacuum? 

    1. YES  - Check for blockage on the EVAP canister port, then go to step  22.
    2. NO  - Replace the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT  ), then go to step  22.
  22. Install the FTP sensor (see FTP SENSOR REPLACEMENT ).
  23. Reconnect all hoses.
  24. Turn the ignition switch ON (II).
  25. Reset the ECM/PCM with the HDS.
  26. Do the ECM/PCM IDLE LEARN PROCEDURE .
  27. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

    Is the result OK? 

    1. YES  - Troubleshooting is complete.
    2. NO  - Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, or the EVAP canister vent shut valve and the ECM/PCM, then go to step  1.
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