Evaporative Emission Control Canister: Description and Operation

PURPOSE

Prevents fuel system damage, by venting the system in the event of high internal pressure or vacuum.

Prevents fuel and vapors from escaping into the atmosphere, (except under extreme conditions, see above).

Top Of Evaporative Canister (Non-Duty Cycle Purge Type):

EVAP Canister Operation:

OPERATION

Under certain conditions, fuel and fuel vapors in the tank expand.

When the volume of the tank is exceded by vapors or fuel and vapors, the overflow is routed, through the pressure relief/rollover valve, into the tube on the EVAP canister labeled "Fuel Tank".

The vapors are absorbed by the carbon, and any liquid fuel enters the reservoir in the bottom of the canister, (to protect the carbon bed above).

The fuel and vapors are stored in the canister, until the engine is started and certain conditions are met, (see Purge Solenoid Operation, below).