DTC P0497: EVAP System Low Purge Flow

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. Check the fuel fill cap installation.

   Is the fuel fill cap installed and properly tightened? 

   1. YES  - Go to step 2.
   2. NO  - Properly install the fuel fill cap (the cap must say "Tighten to click"). It should turn 1/4 turn after it's tight, then go to step  23.
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, the EVAP canister vent shut valve, and the 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  23.
6. Disconnect the vacuum hose (A) from the purge joint (B) in the engine compartment, and connect a T-fitting (C) from the vacuum gauge and the vacuum pump/gauge, 0-30 in.Hg, to the vacuum hose (A) as shown in Fig 1.
   Fig 1: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge To Vacuum Hose

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
7. Select EVAP PCS ON in the INSPECTION MENU with the HDS.
8. Slowly apply about 0.6 in.Hg (15 mmHg) of vacuum to the hose.
   1. Does it hold vacuum? 
   2. YES  - Replace the EVAP canister purge valve, then go to step  22.
   3. NO  - Go to step 9.
9. Reconnect the vacuum hose to the purge joint.
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 in Fig 2.
    Fig 2: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge To Hose

    Courtesy 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.
    1. Does it hold vacuum? 
    2. YES  - Check for a restricted EVAP canister purge line between the EVAP canister purge valve and the EVAP canister, then go to step  22.
    3. 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 pump to the FTP sensor (B) as shown in Fig 3.
    Fig 3: Connecting T-Fitting From Vacuum Pump/Gauge And Vacuum Pump To FTP Sensor

    Courtesy 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  22.
18. Reconnect the vacuum hoses to the EVAP canister purge line (EVAP canister side), and reinstall the FTP sensor.
19. Disconnect the vacuum hose (purge line) (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 in Fig 4.
    Fig 4: Connecting T-Fitting From Vacuum Gauge And Vacuum Pump/Gauge To Hose

    Courtesy 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.
    1. Does the hose hold vacuum? 
    2. YES  - Check for blockage at the EVAP canister port, then go to step 22.
    3. NO  - Replace the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT  ), then go to step 22.
22. Reconnect all hoses.
23. Turn the ignition switch ON (II).
24. Reset the PCM with the HDS.
25. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
26. 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, the EVAP canister vent shut valve, and the PCM, then go to step  1.