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 the 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 (31 P).
24. Connect the 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.