DTC P0457: EVAP System Leak Detected/Fuel Fill Cap Loose or Missing (2006 model)

NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

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?
1. YES -Go to step 2.
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). Make sure the fuel fill cap tether cord (C) is not caught under the cap.

Fig 1: Checking Fuel Fill Cap Seal And Fuel Fill Pipe Mating Surface
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?
1. YES -Replace the fuel fill cap or the fuel fill pipe, then go to step 19.
2. 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?
1. YES -Intermittent failure, 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.
2. NO -Go to step 6.
Turn the ignition switch OFF.
Remove the EVAP canister vent shut valve from the EVAP canister (see FTP SENSOR 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.

Fig 2: Checking EVAP Canister Vent Shut Valve Operation
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the valve operate?
1. YES -Check the routing of the EVAP canister vent tube, then go to step 18.
2. NO -Go to step 12.
Turn the ignition switch OFF.
Replace the EVAP canister vent shut valve (see FTP SENSOR REPLACEMENT ).
Turn the ignition switch ON (II).
Reset the ECM with the HDS.
Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
Is the result OK?
1. YES -Troubleshooting is complete.
2. NO -Check for poor connections or loose terminals at the FTP sensor, the EVAP canister vent shut valve, and the ECM, then go to step 16.
Reinstall the EVAP canister vent shut valve (see FTP SENSOR REPLACEMENT ).
Turn the ignition switch ON (II).
Reset the ECM with the HDS.
Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.
Is the result OK?
1. YES -Troubleshooting is complete.
2. NO -Check for poor connections or loose terminals at the FTP sensor, the EVAP canister vent shut valve, and the ECM, then go to step 1.