P0456
DTC P0456: EVAP System Very Small Leak DetectedSpecial Tools Required
- Vacuum pump/gauge, 0 - 30 in.Hg A973X-041-XXXXX
- Vacuum/pressure gauge, 0 - 4 in.Hg 07JAZ-001000B
NOTE: If DTC P0461 is stored at the same time as DTC P0456, troubleshoot DTC P0461 first, then recheck for DTC P0456.
1. Check the fuel fill cap (the cap must say "If not tightened 3 clicks, check engine light may come on").
Is the correct fuel fill cap installed and properly tightened?
YES - Go to step 2.
NO - Replace or tighten the cap, then go to step 37.
2. Check the fuel fill cap seal (A) and the fuel fill pipe mating surface (B).
Is the fuel fill cap seal missing or damaged, or is the fuel fill pipe damaged?
YES - Replace the fuel fill cap or the fuel fill pipe, then go to step 37.
NO - Go to step 3.
3. Turn the ignition switch ON (II).
4. Clear the DTC with the HDS.
5. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
Is the EVAP SYSTEM normal?
YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the FTP sensor and the EVAP bypass solenoid valve, or at the EVAP canister vent shut valve, the EVAP canister purge valve, and the PCM.
NO - Go to step 6.
6. If "Small leak is detected in Canister" is indicated, go to step 7.
If "Small leak is detected in Tank" is indicated, go to step 28.
7. Turn the ignition switch OFF.
8. Disconnect the two vapor hoses (A) from the EVAP two way valve (B).
9. Plug the tank side port (C) of the EVAP two way valve.
10. Connect a T-fitting (D) from the vacuum gauge an the vacuum pump to the EVAP two way valve.
11. Turn the ignition switch ON (II).
12. Do the EVAP BPS ON in the INSPECTION MENU with the HDS.
13. Slowly apply 0.4 in.Hg (10 mmHg) of vacuum to the hose.
Does it hold vacuum for about 20 seconds?
YES - Go to step 14.
NO - Replace the EVAP two way valve or O-ring, then go to step 37.
14. Reconnect the fuel tank side vapor hose (A) to the EVAP two way valve (B) and plug the canister side vacuum hose (C).
15. Check the connection of the fuel tank vapor control valve vent hose and quick-connect fitting,
Is the hose connected properly?
YES - Go to step 16.
NO - Reconnect the fuel tank vapor control valve vent hose or the quick-connect fitting, then go to step 37.
16. Disconnect the fuel tank vapor control valve vent hose (A) from the EVAP canister (B) and plug the canister port (C).
17. Disconnect the vacuum hose (A) between the EVAP canister and the EVAP canister purge valve (B) from the EVAP canister purge valve side.
18. Connect a T-fitting (C) from the vacuum gauge and the vacuum pump to the vacuum hose.
19. Slowly apply 0.6 in.Hg (15 mmHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES - Inspect the fuel tank vapor control valve vent hose. If OK, replace the fuel tank vapor control valve, then go to step 37.
NO - Go to step 20.
20. Disconnect all drain hoses from the EVAP canister vent shut valve, and plug their ports.
21. Slowly apply 0.6 in.Hg (15 mmHg) of vacuum to the hose.
Does it hold vacuum for 1 minute?
YES - Replace the EVAP canister vent shut valve, then go to step 37.
NO - Go to step 22.
22. Disconnect the vacuum hose (VSV line) (A) between the EVAP canister (B) and EVAP canister vent shut valve from the EVAP canister side, and plug the EVAP canister port (C).
23. Slowly apply 0.6 in.Hg (15 mmHg) of vacuum to the hose,
Does it hold vacuum for 1 minute?
YES - Check the hose between the EVAP canister vent shut valve and EVAP canister. If the hose is OK, replace the EVAP canister vent shut valve, then go to step 37.
NO - Go to step 24.
24. Reconnect the vacuum hose to the EVAP canister purge valve.
25. Disconnect the vacuum hose (A) between the EVAP canister (B) and the EVAP canister purge valve from
26. Connect a T-fitting (C) from the vacuum gauge and the vacuum pump to the vacuum hose (A).
27. Slowly apply 0.6 in.Hg (15 mmHg) of vacuum to the hose.
Dose it hold vacuum?
YES - Check for a cracked or damaged EVAP canister. If the EVAP canister is OK, go to step 40.
NO - Check the hose between the EVAP canister purge cut valve and EVAP canister. If the hose is OK, replace the EVAP canister purge cut valve, then go to step 37.
28. Turn the ignition switch OFF.
29. Disconnect the two vapor hoses (A) from the EVAP two way valve (B).
30. Plug the tank side port (C) of the EVAP two way valve.
31. Connect a T-fitting (D) from the vacuum gauge and the vacuum pump to the EVAP two way valve.
32. Turn the ignition switch ON (II).
33. Do the EVAP BPS ON in the INSPECTION MENU with the HDS.
34. Slowly apply 0.4 in.Hg (10 mmHg) of vacuum to the hose.
Does it hold vacuum for about 20 seconds?
YES - Go to step 35.
NO - Replace the EVAP two way valve or O-rings, then go to step 37.
35. Test the fuel tank vapor control valve.
Is the fuel tank vapor control valve OK?
YES - Go to step 36.
NO - Replace the fuel tank vapor control valve, then go to step 37.
36. Check for poor connection of the fuel tank vapor tube, fuel tank vapor recirculation tube, fuel tank vapor signal tube, FTP sensor hoses, and the vapor line between the EVAP two way valve and the fuel tank.
Are all the connections OK?
YES - Remove the fuel tank unit, and check its seal and mating surface, then go to step 37.
NO - Reconnect or replace the loose hose, then then go to step 38.
37. Reconnect all hoses and connectors.
38. Turn the ignition switch ON (II).
39. Reset the PCM with the HDS.
40. Do the PCM idle learn procedure.
41. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
Is the EVAP SYSTEM normal?
YES - Troubleshooting is complete.
NO - Check for poor connections or loose terminals at the FTP sensor, the EVAP bypass solenoid valve, the EVAP canister vent shut valve, or EVAP canister purge valve and the PCM, then go to step 1.