Except AT-PZEV (SULEV) Model
DTC P0497: EVAP System Low Purge Flow DetectedSpecial Tools Required
Vacuum pump/gauge, 0 - 30 in.Hg A973X-041-XXXXX
Except AT-PZEV
1. Turn the ignition switch ON (II).
2. Measure voltage between ECM connector terminal 821 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/purge 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 19.
8. Turn the ignition switch OFF.
9. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after the radiator fan stops.
10. Disconnect the ECM connector B (24P).
11. Connect the ECM connector terminal B21 to body ground with a jumper wire.
12. Remove the intake manifold.
13. Connect the intake manifold subharness 14P connector (C108) to the engine wire harness.
14. Disconnect the EVAP canister purge valve 2P connector.
15. Check for continuity between the EVAP canister purge valve 2P connector No. 2 and body ground.
Is there continuity?
YES - Go to step 16.
NO - Repair open in the wire between the EVAP canister purge valve and the ECM (B21).
16. Turn the ignition switch ON (II).
17. Measure voltage between the EVAP canister purge valve 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES - Go to step 18.
NO - Repair open in the wire between the EVAP canister purge valve and the No. 4 FI-ECU (10 A) fuse in the under-dash fuse/relay box.
18. Measure resistance 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 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.
NO - Replace the EVAP canister purge valve.
19. Measure voltage between ECM connector terminal E21 and body ground.
Is there battery voltage?
YES - Go to step 20.
NO - Go to step 25.
20. Turn the ignition switch OFF.
21. Disconnect the vacuum hose from the EVAP canister vent filter line (A) and connect a vacuum pump/gauge to the hose.
22. Connect the ECM connector terminal E21 to body ground with a jumper wire.
23. Turn the ignition switch ON (II).
24. Apply vacuum to the hose.
Does the valve hold vacuum?
YES - Inspect the vacuum line between the EVAP canister purge valve and EVAP canister.
NO - Replace the EVAP canister vent shut valve.
25. Turn the ignition switch OFF.
26. Wait for 1 minute. If the radiator fan is running, wait for 1 minute after the radiator fan stops.
27. Disconnect the ECM connector E (31P).
28. Connect the ECM connector terminal E21 to body ground with a jumper wire.
29. Disconnect the EVAP canister vent shut valve 2P connector.
30. Check for continuity between the EVAP canister vent shut valve 2P connector No. 2 and body ground.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between the EVAP canister vent shut valve and the ECM (E21).
31. Turn the ignition switch ON (II).
32. 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 33.
NO - Repair open in the wire between the EVAP canister vent shut valve and the No. 4 PI-ECU (10 A) fuse in the under-dash fuse/relay box.
33. 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 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.
NO - Replace the EVAP canister vent shut valve.