Evaporative Emission Control Canister: Description and Operation

ORVR Vapor Line:

The EVAP (vapor) canister (1), Natural Vacuum Leak Detection (NVLD) pump (3) and pump filter are attached to a common support bracket. This support assembly is located to the rear of the right / rear tire under the plastic wheelhouse liner.

A maintenance free, EVAP canister is used on all vehicles. The EVAP canister is filled with granules of an activated carbon mixture. Fuel vapors entering the EVAP canister are absorbed by the charcoal granules.

Fuel tank pressure vents into the EVAP canister. Fuel vapors are temporarily held in the canister until they can be drawn into the intake manifold. The duty cycle EVAP canister purge solenoid allows the EVAP canister to be purged at predetermined times and at certain engine operating conditions.

The EVAP canister is also to be considered as part of the ORVR system.