ULEV Model
DTC P0497: EVAP System Low Purge Flow Detected (ULEV model)Special Tools Required
Vacuum pump/gauge, 0 - 30 in.Hg, Snap-on YA4000A or equivalent, commercially available
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/purge, 0 - 30 in.Hg, to the hose.
5. Connect 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 it stops.
10. Disconnect ECM connector B (24P).
11. Connect 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 EVAP canister purge valve 2P connector terminal 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 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 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, replace the original 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, 0 - 30 in.Hg, to the hose.
22. Connect 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 it stops.
27. Disconnect ECM connector E (31P).
28. Connect 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 EVAP canister vent shut valve 2P connector terminal No.2 and body ground.
Is there continuity?
YES - Go to step 31.
NO - Repair open in the wire between EVAP canister vent shut valve and the ECM (E21).
31. Turn the ignition switch ON (II).
32. Measure voltage between 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 EVAP canister vent shut valve and the No.4 FI-ECU (10 A) fuse in the under-dash fuse/relay box.
33. 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 - 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.