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 the general troubleshooting information (see 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 20.
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 Fuel Fill Cap Seal, Mating Surface And 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 20.

NO - Go to step 3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
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, the EVAP canister vent shut valve, and the ECM/PCM.

NO - Go to step 6.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Remove the EVAP canister vent shut valve from the EVAP canister; without SH-AWD (see WITH SH-AWD ), with SH-AWD (see WITH SH-AWD ).
Connect the 2P connector to the EVAP canister vent shut valve.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
Select EVAP CVS ON in the INSPECTION MENU with the HDS.
Check the EVAP canister vent shut valve (A) operation.

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

Does the valve operate?

YES - Go to step 18.

NO - Go to step 12.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Replace the EVAP canister vent shut valve; without SH-AWD system (see WITH SH-AWD ), with SH-AWD system (see WITH SH-AWD ).
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
Reset the ECM/PCM with the HDS.
Do the ECM/PCM idle learn procedure (see 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, the EVAP canister vent shut valve, and the ECM/PCM, then go to step 1.
Check the EVAP canister vent tube.
Is there any damage or blockage?

YES - YES-Remove the blockage, and replace the EVAP canister vent tube if needed, then go to step 19.

NO - Do the DTC P0455 troubleshooting (see DTC P0455: EVAP SYSTEM LARGE LEAK DETECTED; DTC P0456: EVAP SYSTEM VERY SMALL LEAK DETECTED ).
Reinstall the EVAP canister vent shut valve.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
Reset the ECM/PCM with the HDS.
Do the ECM/PCM idle learn procedure (see 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, the EVAP canister vent shut valve, and the ECM/PCM, then go to step 1.