P0497

DTC P0497: EVAP System Low Purge Flow (2004 - 2005 models)

Special Tools Required
Vacuum pump/gauge, 0 - 30 in.Hg, Snap-on YA4000A or equivalent, commercially available

NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information.

1. Turn the ignition switch ON (II).




2. Measure voltage between ECM connector terminal A6 and body ground.

Is there battery voltage?

YES - Go to step 3.

NO - Go to step 8.

3. Turn the ignition switch OFF.




4. Disconnect the vacuum hose from the EVAP purge joint (A), and connect a commercially available vacuum pump/gauge, 0-30 in.Hg, to the hose.




5. Connect ECM connector terminal A6 to body ground with a jumper wire.
6. Turn the ignition switch ON (II).
7. Apply vacuum to the hose.

Does the valve hold vacuum?

YES - Replace the EVAP canister purge valve.

NO - Go to step 14.

8. Turn the ignition switch OFF.
9. Disconnect the EVAP canister purge valve 2P connector.




10. Check for continuity between EVAP canister purge valve 2P connector terminal No. 2 and body ground.

Is there continuity?

YES - Go to step 11.

NO - Repair open in the wire between the EVAP canister purge valve and the ECM (A6).

11. Turn the ignition switch ON (II).




12. Measure voltage between EVAP canister purge valve 2P connector terminal No. 1 and body ground.

Is there battery voltage?

YES - Go to step 13,

NO - Repair open in the wire between the EVAP canister purge valve and the No. 6 ACG (15 A) fuse in the under-dash fuse/relay box.




13. Measure resistance between EVAP canister purge valve 2P connector terminals No. 1 and No. 2.

Is there about 33 Ohm, at room temperature?

YES - Go to step 14.

NO - Replace the EVAP canister purge valve.




14. Measure voltage between ECM connector terminal A4 and body ground.

Is there battery voltage?

YES - Go to step 15.

NO - Go to step 20.

15. Turn the ignition switch OFF.




16. Disconnect the vacuum hose from the EVAP canister vent filter line (A), and connect a commercially available vacuum pump/gauge, 0 - 30 in.Hg, to the hose.




17. Connect ECM connector terminal A4to body ground with a jumper wire.
18. Turn the ignition switch ON (II).
19. Apply vacuum to the hose.

Does the valve hold vacuum?

YES - Inspect the vacuum line between the EVAP canister purge valve and the EVAP canister.

NO - Replace the EVAP canister vent shut valve.

20. Turn the ignition switch OFF.
21. Disconnect the EVAP canister vent shut valve 2P connector.




22. Check for continuity between EVAP canister vent shut valve 2P connector terminal No. 2 and body ground.

Is there continuity?

YES - Go to step 23.

NO - Repair open in the wire between the EVAP canister vent shut valve and the ECM.

23. Turn the ignition switch ON (II).




24. Measure voltage between EVAP canister vent shut valve 2P connector terminal No. 1 and body ground.

Is there battery voltage?

YES - Go to step 25.

NO - Repair open in the wire between the EVAP canister vent shut valve and the No. 6 ACG (15 A) fuse in the under-dash fuse/relay box.




25. Measure resistance between EVAP canister vent shut valve 2P connector terminals No. 1 and No. 2.

Is there about 33 Ohm at room temperature?

YES - Substitute a known-good ECM and retest. If the symptom/indication goes away, replace the original ECM.

NO - Replace the EVAP canister vent shut valve.