Canister Purge Solenoid: Description and Operation

Canister Purge Solenoid Circuit:

To regulate the canister purge, an ECM controlled electronic vacuum valve solenoid is used. The ECM uses information from various sensors to regulate the solenoid. If the following conditions are met with the engine running, the canister purge solenoid is energized:

1. The engine run time is greater than one minute.
2. Coolant Temperature is above 75°C (167°F).
3. Vehicle speed sensor (VSS) is above 15 mph.
4. Throttle Position Sensor (TPS) signal is approximately .75 volts and the throttle valve is above idle.