EVAP Canister Air Valve

When ECM/PCM signals canister purge valve, fuel vapors flow from charcoal canister into combustion chambers for burning. A condition then exist, where after, EVAP canister is purged or cleaned by air drawn through filter and EVAP canister air valve. Also ECM/PCM signals EVAP canister air valve On (closed) when specific conditions are met to run a leak detection monitor.