DTC P0497: EVAP System Low Purge Flow Detected

Special Tools Required 

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

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  -If the EVAP FUNCTION TEST failed because of a stored DTC, do the indicated DTC's troubleshooting, then go to step 4.

4. Turn the ignition switch to LOCK (0).
5. Check for poor connections, 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: Identifying Vacuum Hose And 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 vacuum pump/gauge, 0-30 in.Hg, to the hose as shown.
   Fig 2: Connecting Vacuum Pump/Gauge

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
8. Turn the ignition switch to ON (II).
9. Apply about 2 kPa (0.6 in. Hg, 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 the T-fitting (C) between the vacuum gauge, the vacuum pump/gauge, 0-30 in.Hg, and the EVAP canister purge valve as shown.
    Fig 3: Connecting T-Fitting Between Vacuum Gauge

    Courtesy of AMERICAN HONDA MOTOR CO., INC.
13. Apply about 2 kPa (0.6 in.Hg, 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 VENT SHUT VALVE REPLACEMENT ), then Go to step  24.

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

    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) from the vacuum pump/gauge, 0-30 in.Hg, then connect the vacuum pump to the FTP sensor (B) as shown.
    Fig 5: Connecting T-Fitting From Vacuum Pump/Gauge

    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 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.
23. Check the FTP SENSOR in the DATA LIST with the HDS.

    Does the value change? 

    YES  -Check for debris or blockage at the EVAP canister port, 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  -Go to step 28.

    NO  -Check for poor connections or loose terminals at the EVAP canister purge valve, the FTP sensor, and PCM, then Go to step  1.

28. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC P0497 indicated? 

    YES  -Check for poor connections or loose terminals at the EVAP canister purge valve, the FTP sensor, and the PCM, then Go to step  1.

    NO  -Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. ■