EVAP System Operation

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

The evaporative emission (EVAP) control system limits fuel vapors from escaping into the atmosphere. Fuel tank vapors are allowed to move from the fuel tank, due to pressure in the tank, through the EVAP vapor tube, into the EVAP canister. Carbon in the canister adsorbs and stores the fuel vapors. The EVAP canister stores the fuel vapors until the engine is able to use them.

The Hybrid Electric Vehicle vented fuel system features a normally vented fuel tank and canister unlike the Extended Range Electric Vehicle/Plug-in Hybrid Electric Vehicle which uses a normally-sealed fuel tank and canister. At an appropriate time, the engine control module (ECM) will command the EVAP purge solenoid valve ON, allowing engine vacuum to be applied to the EVAP canister. Fresh air is drawn through the canister, pulling fuel vapors from the carbon. The air/fuel vapor mixture continues through the EVAP purge tube and EVAP purge solenoid valve into the intake manifold to be consumed during normal combustion. Excess pressure is vented through the vent hose and EVAP canister to the atmosphere at a predetermined limit. Diagnostics are performed with the propulsion system ON and OFF.