Canister Purge Solenoid: Description and Operation

EVAP System:

PURPOSE
Through its control of this solenoid valve, the PCME regulates the evaporative emission control system (EVAP) according to engine operating conditions.

LOCATION
Engine compartment, near center of firewall.

OPERATION
The solenoid valve is a normally closed vacuum solenoid valve that opens when energized. It gets battery power from the main relay when the ignition is turned ON, and is energized when the PCME completes the circuit to ground. It operates on duty cycle signals (ON time vs. OFF time) from the PCME. When energized, fuel vapors stored in the charcoal canister are allowed into the intake system to be burned with the normal air/fuel charge. The PCME allows canister purging under these conditions:
^ Engine at operating temperature.
^ Vehicle being driven in gear.
^ Accelerator pedal depressed (idle switch OFF).
^ Oxygen sensor functioning properly.