Evaporative Emission Control: Notes

Carbon canister storage is used for evaporative fuel control on all vehicles. The function of evaporative emission control system is to store gasoline fumes from fuel tank in a carbon canister until fumes can be drawn into engine for burning during combustion process.

Evaporative emission system uses 4 basic components:

• Activated carbon canister (may be sealed or open at top or bottom for fresh air intake).
• Tank pressure control valve (mounted internally or externally to fuel tank).
• PCM-controlled canister purge control solenoid (mounted in-line or on canister).
• Canister purge control valve (mounted in-line or on canister).

For specific component application, see appropriate EMISSION APPLICATIONS article. For vacuum hose routing, see appropriate wiring diagram in WIRING DIAGRAMS article.