DTC P1456

Evaporative Emission (EVAP) Control System Leak Detected (Fuel Tank System)

NOTE:
The symbol of "filled black square" indicates end of troubleshooting.

1. Check the fuel fill cap (The cap must be a gray OEM cap and be tightened at least three "clicks" to properly seal the system.)

Is the proper fuel cap installed and properly tightened?

YES - Go to step 2.

NO - Replace or tighten the cap. (filled black square)

2. Turn the ignition switch ON (II). Attach the Honda PGM-FI Tester with SN812 or later software to the 16P data link connector, and select the PGM-FI menu item. Go to the Data List screen and then select the All Data List.

3. Start the engine. Let the engine idle for five minutes.

4. Check the fuel tank pressure sensor readings.

Is the reading above 4 mm Hg pressure or below -4 mm Hg vacuum?

YES - The system is normal at this time; go to step 6.

NO - Go to step 5.

5. Check the fuel fill cap seal.

Is the fuel fill cap seal missing or damaged?

YES - Replace the fuel fill cap (gray colored cap). (filled black square)

NO - Go to step 6.





6. Remove the vacuum hose from the two-way valve, and connect a hand vacuum pump to the two-way valve. Apply vacuum (one squeeze only).

Does the valve hold vacuum?

YES - The two-way valve is functioning properly at this time; go to step 7.

NO - Possible problem with the EVAP bypass solenoid or two-way valve; go to step 14.

7. Turn the ignition switch OFF.





8. Connect the ECM/PCM terminal A3 to body ground with a jumper wire.

9. Turn the ignition switch ON (II).

10. Apply only one squeeze of vacuum to the two-way valve.

Does the valve hold vacuum?

YES - Possible problem with the EVAP bypass solenoid or two-way valve; go to step 16.

NO - The bypass solenoid is functioning properly at this time; go to step 11.





11. Fill the gas tank with fuel, then check for fuel in the two-way valve and ORVR vapor recirculation hose.

NOTE:
At either location, tiny droplets of fuel are normal.

Does fuel run out of the hoses at either location?

YES - The ORVR valve is faulty, replace the ORVR valve. filled black square

NO - The ORVR function is normal; go to step 12.

12. Check for loose hose connections at the fuel filler neck.

Are the hose connections loose?

YES - Tighten or reconnect the hose connections. (filled black square)

NO - Go to step 13.

13. Remove the fuel tank. Look for cracks and damage in the tank and the ORVR, and confirm that the ORVR gasket is in good condition. (filled black square)





14. Disconnect the EVAP bypass solenoid valve 2P connector.

15. Apply only one squeeze of vacuum to the two-way valve.

Does the valve hold vacuum?

YES - Repair the short in the wire between the EVAP bypass solenoid valve and the ECM/PCM terminal A3. If the wire is OK, replace the ECM/PCM. (filled black square)

NO - Replace the EVAP bypass solenoid valve, the O-rings, and the EVAP two-way valve. (filled black square)





16. Measure the voltage between the EVAP bypass solenoid valve 2P connector terminal No. 1 and body ground.

Is There battery voltage?

YES - The system function is OK; go to step 17.

NO - Repair the open in the wire between the EVAP bypass solenoid valve 2P connector terminal No. 1 and the No. 6 (15 A) fuse in the driver's under-dash fuse/relay box. (filled black square)

17. Turn the ignition switch OFF.

18. Check for continuity between the ECM/PCM terminal A3 and the EVAP bypass solenoid valve 2P connector terminal No. 2.

Is there continuity?

YES - Replace the EVAP bypass solenoid valve, the O-rings, and the EVAP two-way valve. (filled black square)

NO - Repair an open in the wire between the ECM/PCM terminal A3 and the EVAP bypass solenoid valve 2P connector terminal No. 2. (filled black square)