DTC P0457: EVAP System Leak Detected/Fuel Fill Cap Loose or Missing

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review GENERAL TROUBLESHOOTING INFORMATION .

Check the fuel fill cap (the cap must say "TIGHTEN TO CLICK"). It should turn 1/4 turn after it's tight, then it clicks.
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 19.
Check the fuel fill cap seal (A) and the fuel fill pipe mating surface (B). Verify that the fuel fill cap tether cord (C) is not caught under the cap.

Fig 1: Identifying Cap Seal, Fuel Fill Pipe Mating Surface & Fuel Fill Cap Tether Cord
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is the fuel fill cap seal missing or damaged, is the fuel fill pipe damaged, or is the tether cord caught under the cap?

YES - Replace the fuel fill cap or the fuel fill pipe, then go to step 19.

NO - Go to step 3.
Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
Is the result OK?

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

NO - Go to step 6.
Turn the ignition switch OFF.
Remove the EVAP canister vent shut valve from the EVAP canister (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT ).
Connect the 2P connector to the EVAP canister vent shut valve.
Turn the ignition switch ON (II).
Select EVAP CVS ON in the INSPECTION MENU with the HDS.
Check the EVAP canister vent shut valve (A) operation.
Does the valve operate?

YES - Check the routing of the EVAP canister vent tube, then go to step 18.

NO - Go to step 12.

Fig 2: Identifying EVAP Canister Vent Shut Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch OFF.
Replace the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT ).
Turn the ignition switch ON (II).
Reset the ECM/PCM with the HDS.
Do ECM/PCM IDLE LEARN PROCEDURE ).
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 or the EVAP canister vent shut valve and the ECM/PCM, then go to step 1.
Reinstall the EVAP canister vent shut valve (see EVAP CANISTER VENT SHUT VALVE REPLACEMENT ).
Turn the ignition switch ON (II).
Reset the ECM/PCM with the HDS.
Do ECM/PCM IDLE LEARN PROCEDURE .
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 or the EVAP canister vent shut valve and the ECM/PCM, then go to step 1.