Evaporation Control System

The evaporation control system prevents the emission of fuel tank vapors into the atmosphere. When fuel evaporates in the fuel tank, the vapors pass through vent hoses or tubes to a charcoal filled evaporative canister. The canister temporarily holds the vapors. The Powertrain Control Module (PCM) allows intake manifold vacuum to draw vapors into the combustion chambers during certain operating conditions.

All engines use a duty-cycle purge system. The PCM controls vapor flow by operating the duty-cycle EVAP purge solenoid. Refer to Duty-Cycle EVAP Canister Purge Solenoid.

An ORVR system is used. This system is part of the EVAP Control System. Refer to On-Board Refueling Vapor Recovery (ORVR) for information.

When equipped with certain emissions packages, a Leak Detection Pump (LDP) will be used as part of the evaporative system for OBD II requirements. Also refer to Leak Detection Pump.

NOTE: The evaporative system uses specially manufactured lines/hoses. If replacement becomes necessary, only use fuel resistant hose.