DTC P0497: EVAP System Low Purge Flow Detected

Special Tools Required 

• Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available
• Vacuum/Pressure Gauge, 0-4 inHg 07JAZ-001000B

1. Turn the ignition switch to ON (II).
2. Clear the DTC with the HDS.
3. Select 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 EVAP canister purge valve, the FTP sensor, and the PCM.

   NO  -Go to step 4.

4. Turn the ignition switch to LOCK (0).
5. Check for a poor connection, a blockage, or damage at the EVAP canister purge line between the throttle body and the EVAP canister.

   Is the line OK? 

   YES  -Go to step 6.

   NO  -Reconnect or repair the EVAP canister purge line, then go to step  24.

6. Disconnect the vacuum hose (A) from the EVAP canister purge valve (B).
   Fig 1: Disconnecting Vacuum Hose From EVAP Canister Purge Valve

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Disconnect the vacuum hose (A) from the purge line (at the EVAP canister side), then connect a T-fitting (B), a vacuum gauge, and a vacuum pump/gauge, 0-30 inHg, to the vacuum hose as shown.
   Fig 2: Connecting T-Fitting Vacuum Gauge And Vacuum Pump/Gauge To Vacuum Hose

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

    Does the vacuum release immediately? 

    YES  -Go to step  15.

    NO  -Go to step 11.

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

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

    Does the vacuum release immediately? 

    YES  -Check for a blockage in the vacuum hose between the EVAP canister purge valve and the EVAP canister, then go to step  24.

    NO  -Replace the EVAP canister purge valve (see EVAP CANISTER PURGE VALVE REPLACEMENT  ), then go to step  24.

15. Connect the vacuum pump/gauge to the vacuum hose (A) as shown.
    Fig 4: Connecting Vacuum Pump/Gauge To Vacuum Hose

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
16. Start the engine, and let it idle.

    Is there vacuum? 

    YES  -Go to step 17.

    NO  -Check for a blockage in the vacuum hose between the EVAP canister purge valve and the intake manifold, then go to step  24.

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

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
20. Turn the ignition switch to ON (II).
21. Check and record the FTP SENSOR reading in the DATA LIST with the HDS.
22. Slowly apply about 1.3 kPa (0.4 inHg, 10 mmHg) of vacuum to the hose.
23. Check the FTP SENSOR in the DATA LIST with the HDS.

    Does the value change? 

    YES  -Check for debris or a blockage at the EVAP canister port and the FTP vent hose, then go to step 24.

    NO  -Replace the FTP sensor (see FTP SENSOR REPLACEMENT  ), then go to step 24.

24. Turn the ignition switch to ON (II).
25. Reset the PCM with the HDS.
26. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
27. Do 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 EVAP canister purge valve, the FTP sensor, and the PCM, then go to step  1.