EVAP Control System

EVAP system minimizes fuel vapor escaping into atmosphere. EVAP control system consists of rollover valves, liquid/vapor separator, an anti-trickle fill valve, EVAP control canister, EVAP canister purge valve, EVAP canister vent valve, EVAP canister vent valve control solenoid and fuel tank pressure sensor.

Fuel vapor inside fuel tank is directed to liquid/vapor separator. There are 2 rollover valves in EVAP system to prevent liquid fuel from entering separator if vehicle rolls over. Liquid/vapor separator tank and anti-trickle fill valve are located in fuel filler neck at right rear of vehicle. Fuel filler cap contains a relief valve to prevent excessive pressure or vacuum build-up in tank.

When ECM detects desired engine operation it opens EVAP control canister purge valve, allowing a regulated flow of fuel vapor from EVAP control canister. Fuel vapor is drawn into intake manifold and burned in combustion chamber. During canister purging, fresh air is drawn into canister through EVAP control vent solenoid valve.