EVAP Purge Solenoid Operation

Canister Purge Solenoid:

PURPOSE

Powertrain Control Module (PCM) controls purge operation by energizing and de-energizing the solenoid.

OPERATION

The PCM controls the purge solenoid by applying and removing the solenoid ground.

- During open loop operation, (including cold start up and hot start time delay), the PCM ENERGIZES the solenoid, preventing canister purge.

- When the engine enters closed loop, (after warm-up and time delay), PCM DE-ENERGIZES solenoid, allowing manifold vacuum to be routed to the EVAP canister.

When manifold vacuum is routed to the canister, it pulls ambient air into the canister through the air tube in the top of the canister. The fuel and vapors stored in the canister mix with the air and are purged from canister, drawn into the engine, and burned in the combustion process.

This valve is also energized (no canister purge), during certain idle conditions, so that fuel delivery can be recalibrated by the PCM.