DTC P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off): Trouble Symptom

WARNING: This page is about a different variant/trim than selected.

Fuel odor
Fuel filler cap loose or lost

CAUTION: After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to OPERATION , Clear Memory Mode, and Inspection Mode Ref. to PROCEDURE , Inspection Mode.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK FUEL FILLER CAP. Turn the ignition switch to OFF. Check the fuel filler cap. NOTE: The DTC is stored in memory if fuel filler cap is or was loose or if the cap chain has caught while tightening.	Is the fuel filler cap tightened securely?	Go to step 2.	Tighten fuel filler cap securely.
2 CHECK FUEL FILLER CAP.	Is the fuel filler cap genuine?	Go to step 3.	Replace with a genuine fuel filler cap.
3 CHECK FUEL FILLER PIPE GASKET.	Is there any damage to the seal between fuel filler cap and fuel filler pipe?	Repair or replace the fuel filler cap and fuel filler pipe. Ref. to FUEL FILLER PIPE .	Go to step 4.
4 CHECK DRAIN VALVE. Install the delivery (test) mode fuse. Turn the ignition switch to ON. Operate the drain valve using the Subaru Select Monitor. NOTE: Drain valve can be operated using the Subaru Select Monitor. For detailed procedures, refer to "SYSTEM OPERATION CHECK MODE". Ref. to SYSTEM OPERATION CHECK MODE .	Does the drain valve operate?	Go to step 5.	Replace the drain valve. Ref. to DRAIN VALVE .
5 CHECK PURGE CONTROL SOLENOID VALVE. Operate the purge control solenoid valve using the Subaru Select Monitor. NOTE: Purge control solenoid valve operation can be executed using Subaru Select Monitor. For detailed procedures, refer to "SYSTEM OPERATION CHECK MODE". Ref. to SYSTEM OPERATION CHECK MODE .	Does the purge control solenoid valve operate?	Go to step 6.	Replace the purge control solenoid valve. Ref. to PURGE CONTROL SOLENOID VALVE .
6 CHECK EVAPORATIVE EMISSION CONTROL SYSTEM LINE. Turn the ignition switch to OFF. Remove the delivery (test) mode fuse.	Is there any disconnection, damage or clogging on the evaporation line?	Repair or replace the evaporation line. Ref. to FUEL DELIVERY AND EVAPORATION LINES .	Go to step 7.
7 CHECK CANISTER.	Is the canister damaged?	Repair or replace the canister. Ref. to CANISTER .	Go to step 8.
8 CHECK FUEL TANK. Remove the fuel tank. Ref. to FUEL TANK .	Is the fuel tank damaged?	Repair or replace the fuel tank. Ref. to FUEL TANK .	Go to step 9.
9 CHECK ANY OTHER MECHANICAL TROUBLE IN EVAPORATIVE EMISSION CONTROL SYSTEM.	Are there holes, cracks, clogging, or disconnections, mis-connection of hoses or pipes in evaporative emission control system?	Repair or replace the hoses or pipes.	Repair the poor contact of ECM connector.