DTC P0497: EVAP System Low Purge Flow Detected

Special Tools Required 

• Vacuum/pressure gauge, 0-4 in.Hg 07JAZ-001000B
• Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Select the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

   Is the result OK? 

   YES  - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the FTP sensor and the PCM.

   NO  - Go to step  4.

4. Check for poor connection, blockage, or damage at the EVAP canister purge line between the throttle body and EVAP canister.

   Is the line OK? 

   YES  - Go to step  5.

   NO  - Reconnect or repair the EVAP canister purge line, then go to step  26.

5. Remove the intake air duct (air flow tube) (see step 19 on page 9-16).
6. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B).
   Fig 1: Identifying Vacuum Hose And EVAP Canister Purge Valve

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Disconnect the vacuum hose from the 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: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge To Hose

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
9. Select EVAP PCS ON in the INSPECTION MENU with the HDS.

   Does the vacuum release immediately? 

   YES  - Go to step  14.

   NO  - Go to step  10.

10. Select EVAP PCS OFF in the INSPECTION MENU with the HDS.
11. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B). Connect a T-fitting (C) from the vacuum gauge and the vacuum pump/gauge, 0-30 in.Hg, to the EVAP canister purge valve as shown.
    Fig 3: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge To EVAP Canister Purge Valve

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
12. Apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
13. Select EVAP PCS ON in the INSPECTION MENU with the HDS.

    Does the vacuum release immediately? 

    YES  - Check for blockage in the vacuum hose between the EVAP canister purge valve and the EVAP canister, then go to step  26.

    NO  - Replace the EVAP canister purge valve (see EVAP CANISTER PURGE VALVE REPLACEMENT ), then go to step  26.

14. Connect the vacuum pump/gauge, 0-30 in.Hg, to the vacuum hose (A) as shown.
    Fig 4: Connecting Vacuum Pump/Gauge To Vacuum Hose

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
15. Reinstall the intake air duct (air flow tube). Start the engine, and let it idle.

    Is there vacuum? 

    YES  - Go to step  18.

    NO  - Go to step  16.

16. Turn the ignition switch OFF.
17. Inspect non-return valve A (see NON-RETURN VALVE A/B INSPECTION/REPLACEMENT ).

    Is the valve OK? 

    YES  - Check for blockage at the EVAP purge line between the throttle body and EVAP canister purge valve, then go to step  26.

    NO  - Replace non-return valve A (see NON-RETURN VALVE A REPLACEMENT ), then go to step  26.

18. Turn the ignition switch to LOCK (0).
19. Remove the FTP sensor with its connector connected (see FTP SENSOR REPLACEMENT ).
20. Connect a T-fitting (A) from the vacuum pump/gauge, 0-30 in.Hg, and the vacuum pump to the FTP sensor (B) as shown.
    Fig 5: Connecting T-Fitting From Vacuum Pump/Gauge And Vacuum Pump To FTP Sensor

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
21. Turn the ignition switch ON (II).
22. Check and record the FTP SENSOR reading in the DATA LIST with the HDS.
23. Slowly apply about 1.3 kPa (0.4 in.Hg, 10 mmHg) of vacuum to the hose.
    NOTE: To avoid FTP sensor damage, do not apply more than 1.3 kPa of vacuum.
24. Check the FTP SENSOR in the DATA LIST with the HDS.

    Does the value change? 

    YES  - Check for debris or blockage at the FTP sensor port and at the EVAP canister, then go to step  26.

    NO  - Go to step  25.

25. Replace the FTP sensor (see FTP SENSOR REPLACEMENT ).
26. Reconnect all hoses.
27. Turn the ignition switch ON (II).
28. Reset the PCM with the HDS.
29. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
30. Select the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

    Is the result OK? 

    YES  - Troubleshooting is complete.

    NO  - Check for poor connections or loose terminals at the FTP sensor and the PCM, then go to step  1.