Diagnostic Help

The diagnostic trouble code indicates a leak in one of the following components:

^ Fuel filler cap not tightened properly, damaged seal, etc.

^ Filler piper or breather pipe

^ Line from fuel tank to tank pressure sensor

^ Tank, above surface of fuel

^ Line from roll-over valve to evaporative emission canister

^ Evaporative emission canister

^ Evaporative emission canister close valve

^ Line from evaporative emission canister to EVAP valve

^ EVAP canister purge valve

It is possible that DTC P0455 might be caused by a fault in the canister close valve circuit. It is important during testing that you make sure the canister close valve works properly, that the circuit from ECM pin # 28 to the canister close valve is ok, and that the canister close valve receives power from the main relay.