DTC Troubleshooting
DTC Troubleshooting: P0497
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
- Fuel pressure gauge attachment set, 07AAJ-S6MA150
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview
1. Check the fuel fill cap installation (the cap must say TIGHTEN TO CLICK. The cap should tighten 1/4 turn after it is tight.).
Is the fuel fill cap installed and properly tightened?
YES - Go to step 2.
NO - Properly install the fuel fill cap, then go to step 23.
2. Turn the ignition switch to 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?
YES - Intermittent failure, the 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 ECM.
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?
YES - Go to step 6.
NO - Reconnect or repair the EVAP canister purge line, then go to step 23.
6. Disconnect the vacuum hose (A) from the EVAP canister purge valve (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 EVAP canister purge valve as shown.
7. Select EVAP PCS ON in the INSPECTION MENU with the HDS.
8. Slowly apply about 2 kPa (0.6 in.Hg, 15 mmHg) of vacuum to the hose.
Does it hold vacuum?
YES - Check for a blockage in the EVAP canister purge line between the intake manifold and the EVAP canister purge valve. If the vacuum hose is OK, replace the EVAP canister purge valve, then go to step 22.
NO - Go to step 9.
9. Reconnect the vacuum hose to the EVAP canister purge valve.
10. Disconnect the vacuum hose from the EVAP canister purge line (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.
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?
YES - Check for a restriction in the EVAP canister purge line between the EVAP canister purge valve and the EVAP canister, then go to step 22.
NO - Go to step 13.
13. Remove the FTP sensor with its connector connected. Service and Repair
14. Connect a T-fitting (A) to the vacuum gauge, the vacuum pump/gauge, and the FTP sensor (B) as shown.
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?
YES - Go to step 18.
NO - Replace the FTP sensor, Service and Repair then go to step 22.
18. Reconnect the vacuum hose 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.
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?
YES - Check for a blockage at the EVAP canister port, then go to step 22.
NO - Replace the EVAP canister vent shut valve, then go to step 22.
22. Reconnect all hoses.
23. Turn the ignition switch to ON (II).
24. Reset the ECM with the HDS.
25. Do the ECM idle learn procedure. ECM Idle Learn Procedure
26. 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 FTP sensor, the EVAP canister purge valve, the EVAP canister vent shut valve, and the ECM, then go to step 1.