The vent valve solenoid is part of the evaporative emissions control system which absorbs fuel vapor from the fuel tank before it can be released into the environment.The vent valve opens to purge the vapors into the fuel system where they are burned in the combustion chambers.The system self-diagnoses when the engine is started, and any faults are reported to the vehicle's main computer. Replacing the vent valve solenoid in a 2000 Silverado is simple and straightforward.ow to Replace the Vent Valve Solenoid on a 2000 Silverado. The vent valve solenoid is part of the evaporative emissions control... 1  How to Verify if a Chevy Tahoe Solenoid Vent Is Clogged.