Evaporative Emissions System: Description and Operation

DESCRIPTION - EVAPORATION CONTROL SYSTEM





The Evaporation Control System prevents the emission of fuel tank vapors into the atmosphere. When fuel evaporates in the fuel tank (1), the vapors pass through vent hoses or tubes (7) and (9) to an activated carbon filled evaporative canister (6). The canister temporarily holds the vapors. Based on input from the Fuel Tank Pressure Sensor (2), the Powertrain Control Module (PCM) (4) actuates the EVAP Purge Solenoid (8), which allows intake manifold vacuum to draw vapors into the combustion chambers during certain operating conditions.

This vehicle uses a pulse-width modulated EVAP Purge Solenoid System. The PCM controls vapor flow by operating the EVAP Purge Solenoid (8). Refer to EVAP Purge Solenoid.