DTC P0442 Or DTC P0455: Description

When engine is running, Engine Control Module (ECM) closes EVAP Canister Vent Valve (EVAP-CVV) and opens EVAP Canister Purge Valve (EVAP-CPV). If EVAP system is okay, EVAP control system pressure which was detected by fuel tank pressure sensor decreases. After which ECM closes EVAP-CPV leaving EVAP-CVV closed. If EVAP control system is okay, fuel tank pressure will then rise a specified rate.