Canister Purge Control Solenoid (CPCS)
WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2002 Saturn Vue, 2002 Pontiac Montana, 2002 Pontiac Aztek, 2002 Oldsmobile Silhouette, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.
The CPCS allows fuel vapor to flow from carbon canister to the engine. CPCS is normally closed and is pulse-width modulated by the PCM to precisely control vapor flow. PCM controls flow of fuel vapors based on coolant temperature. At temperatures greater than 113°F (45°C), purge control solenoid is open. Purge control solenoid is also opened if PCM detects extreme lean air/fuel mixture ratio conditions.