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/PCM 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/PCM 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/PCM 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/PCM (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 (10 A) 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 Ohm at room temperature?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM,then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Replace the EVAP canister purge valve.
16. Measure voltage between ECM/PCM 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 ECM/PCM 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 ECM/PCM 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/PCM (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 (10 A) 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 Ohm at room temperature?
YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO - Replace the EVAP canister vent shut valve.