Evaporative Emissions (EVAP) Control System Diagram: Notes

The EVAP control system minimizes the fuel vapor escaping to the atmosphere. Vapor from the fuel tank is temporarily stored in the EVAP canister until it can be purged from the canister into the engine and burned. The purge amount and timing is duty controlled by the PCM by operating the EVAP canister purge valve. This system is operated whenever the engine coolant temperature is above 140°F(60°C). For this turbo engine model, there are two different purge flow passages, because the intake manifold pressure can be positive (boost pressure) or negative (vacuum pressure).