P0456

DTC P0456: EVAP System Very Small Leak Detected (AT-PZEV (SULEV) model)

NOTE: The fuel system is designed to allow specified maximum vacuum and pressure conditions. Do not deviate from the vacuum and pressure tests as indicated in these procedures. Excessive pressure/vacuum would damage the EVAP components or cause eventual fuel tank failure.

Special Tools Required
- Vacuum pump/gauge, 0 - 30 in.Hg, Snap-on YA4000A or equivalent, commercially available
- Vacuum/pressure gauge, 0 - 4 in.Hg 07JAZ-001000B

NOTE: Fresh fuel has a higher volatility that will create greater pressure/vacuum. The optimum condition for testing is less than a full tank of fresh fuel. If possible, to assist in leak detection, add 1 gallon of fresh fuel to the tank (as long as it will not fill the tank) just before starting these procedures.

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 22.




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 22.

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 result OK?

YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, or the EVAP canister vent shut valve and the ECM.

NO - Go to step 6.

6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (II).
8. Check for a poor connection or damage at the fuel tank vapor recirculation tube.

Is the tube OK?

YES - Go to step 9.

N0 -
- Replace the fuel tank vapor recirculation tube, then go to step 22.
- If necessary, replace the fuel tank, then go to step 22.




9. Disconnect the fuel tank vapor recirculation tube (A) from the EVAP canister (B), and plug the EVAP canister port (C).




10. Disconnect the vacuum hose from the PCS line (EVAP canister purge valve side) and connect a, T-fitting (A) from the vacuum gauge and the vacuum pump/gauge, 0 - 30 in.Hg, to the hose as shown.
11. Do the EVAP CVS ON in the INSPECTION MENU with the HDS.
12. Apply vacuum to the hose until FTP reads 1.90 V (-0.5 in.Hg, -14.6 mmHg)
13. Check the FTP SENSOR in the DATA LIST for 1 minute with the HDS.

Does the voltage stay within 0.2 V (0.1 in.Hg, 0.5 mmHg)?

YES - Go to step 19.

NO - Go to step 14.

14. Do the EVAP CVS OFF in the INSPECTION MENU with the HDS.




15. Disconnect the purge air hose (A) from the EVAP canister vent shut valve (B), and plug the EVAP canister vent shut valve port (C).
16. Apply vacuum to the hose (disconnected in step 10) until FTP reads 1.90 V (-0.5 in.Hg, -14.6 mmHg).
17. Check the FTP SENSOR in the DATA LIST for 1 minute with the HDS.

Does the voltage stay within 0.2 V (0.1 in.Hg, 0.5 mmHg)?

YES - Replace the EVAP canister vent shut valve, then go to step 21.

NO - Go to step 18.

18. Check for a loose or damaged PCS line between the EVAP canister and the EVAP canister purge valve.

Is the line OK?

YES - Replace the following parts, then go to step 21.
- FTP sensor O-ring
- EVAP canister vent shut valve case and O-ring
- EVAP canister

NO - Reconnect or repair the PCS hose, then go to step 21.

19. Do the EVAP CVS OFF in the INSPECTION MENU with the HDS.
20. Check these parts for looseness or damage.
- Fuel fill pipe
- Fuel vapor return pipe

Are the parts OK?

YES - Check the fuel pump base gasket, and check the fuel tank, then go to step 21.

NO - Repair or replace any damaged parts, then go to step 21.

21. Reconnect all hoses.
22. Turn the ignition switch ON (II).
23. Reset the ECM with the HDS.
24. Do the ECM idle learn procedure.
25. Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

Is the result OK?

YES - Troubleshooting is complete.

NO - Check for poor connections or loose terminals at the FTP sensor, the EVAP canister purge valve, or the EVAP canister vent shut valve and the ECM, then go to step 1.