Canister Purge Solenoid: Description and Operation

Canister Purge Wiring Diagram:

The canister purge is controlled by a solenoid that allows vacuum to purge the canister when de-energized. The ECM supplies a ground to energize the solenoid (purge "OFF"). The purge solenoid controlled by the ECM is Pulse Width Modulated. The duty cycle is calculated by the ECM and commands the output when the following conditions have been met.

^ Engine run time after start more than 3 minute.
^ Coolant temperature above 80°C (176°F).
^ Vehicle speed above 15 m.p.h.
^ Throttle off idle.