EVAP/Purge Solenoid

The duty cycle EVAP purge solenoid regulates rate of vapor flow from EVAP canister to throttle body. The Powertrain Control Module (PCM) operates solenoid.

During cold start warm-up period and hot start time delay, PCM does not energize solenoid. When de-energized, no vapors are purged.

When purging PCM energizes and de-energizes solenoid approximately 5 or 10 times per second, depending upon operating conditions. The PCM varies vapor flow rate by changing solenoid pulse width. Pulse width is amount of time solenoid energizes.