Caravan AWD V6-201 3.3L (1991)
Canister Purge Solenoid: Description and Operation
Canister Purge Solenoid/Charcoal Canister
The canister purge solenoid controls the vacuum to the vapor canister. The canister purge solenoid is controlled by the engine controller. The engine
controller controls this solenoid by applying or removing the ground from its circuit. If the engine controller applies the ground, the solenoid becomes
ENERGIZED; whereas, if the engine controller removes the ground, the solenoid becomes DE-ENERGIZED. When the solenoid is ENERGIZED, it
prevents vacuum from flowing to the vapor canister. When it is DE-ENERGIZED, vacuum is allowed to flow to the vapor canister and the canister gets
purged of its vapors.
During engine warm-up and for a set period of time after hot starts, the engine controller ENERGIZES the solenoid, preventing canister purge. When
the engine reaches a specific operating temperature and the time delay has elapsed, the solenoid is DE-ENERGIZED, allowing the canister to purge its
vapors through the throttle body. The purge solenoid will also be ACTIVATED under certain idle conditions, to maintain fuel delivery calibration.
