P0497
DTC P0497: EVAP System Low Purge FlowSpecial Tools Required
Vacuum pump/gauge, 0-30 in.Hg A973X-041-XXXXX
1. Turn the ignition switch ON (II).
2. Measure voltage between ECM connector terminal B21 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 (A) from the EVAP canister purge valve (B) and connect a vacuum pump/gauge to the hose.
5. Connect the ECM connector terminal B21 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 16.
8. Turn the ignition switch OFF.
9. Disconnect the ECM connector B (24P).
10. Connect the ECM connector terminal B21 to body ground with a jumper wire.
11. Disconnect the EVAP canister purge valve 2P connector.
12. Check for continuity between the EVAP canister purge valve 2P connector No.2 and body ground.
Is there continuity?
YES - Go to step 13
NO - Repair open in the wire between the EVAP canister purge valve the ECM (B21).
13. Turn the ignition switch ON (II).
14. Measure voltage between the EVAP canister purge valve 2P connector terminal No.1 and body ground.
Is there battery voltage?
YES - Go to step 15
NO - Repair open in the wire between the EVAP canister purge valve and the No.4 ACG (10A) fuse in the under-dash fuse/relay box
15. Measure resistence between the EVAP canister purge valve 2P connector terminals No.1 and No.2
Is there about 33 Ohms at room temperature?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM
NO - Replace the EVAP canister purge valve
16. Measure voltage between ECM connector terminal E21 and body ground
Is there battery voltage?
YES - Go to step 17
NO - Go to step 22
17. Turn the ignition switch OFF.
18. Disconnect the vacuum hose from the EVAP canister vent filter line (A) and connect a vacuum pump/gauge to the hose.
19. Connect the ECM connector terminal E21 to body ground with a jumper wire.
20. Turn the ignition switch ON (II).
21. 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.
22. Turn the ignition switch OFF.
23. Disconnect the ECM connector E (31P).
24. Connect the ECM connector terminal E21 to body ground with a jumper wire.
25. Disconnect the EVAP canister vent shut valve 2P connector.
26. Check for continuity between the EVAP canister vent shut valve 2P connector No.2 and body ground
Is there continuity?
YES - Go to step 27.
NO - Repair open in the wire between the EVAP canister vent shut valve and the ECM (E21).
27. Turn the ignition switch ON (II).
28. Measure voltage between the EVAP canister vent shut valve 2P connector terminal No.1 and body ground.
Is there battery voltage?
YES - Go to step 29.
NO - Repair open in the wire between the EVAP canister vent shut valve and the No.4 ACG (10A) fuse in the under-dash fuse/relay box.
29. Measure resistance between the EVAP canister vent shut valve 2P connector terminals No.1 and No.2.
Is there about 33 Ohms at room temperature?
YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
NO - Replace the EVAP canister vent shut valve.