The vent solenoid on a Chevy Tahoe is part of the evaporative emissions control system that absorbs fuel vapors from the fuel tank. These vapors are released through the vent solenoid and into the combustion chamber where they are burned. Because the system performs a self-diagnostic test each time the engine is started, a problem with the vent solenoid will cause the vehicle's on-board computer to generate a problem code that can be read by a diagnostic tool. A faulty vent solenoid must be replaced.
Locate the diagnostic connector underneath the instrument panel, directly above the parking brake lever.
Plug a diagnostic scan tool into the connector to read the code. If a scan tool is not available, have a Chevrolet dealer service department diagnose the problem for you. Problem Code P0446 relates to vent solenoid performance.
Follow the steps in the next section to replace the vent solenoid if it is faulty.
Raise the rear of the Tahoe with a jack, and then slowly lower it onto jack stands.
Locate the vent solenoid, mounted on a bracket next to the fuel tank on the driver's side. Pull the electrical connector out of the terminal attached to its end. Remove the hose fitting by squeezing the retainer tabs together and pulling the fitting off.
Pull the retainers apart to release the vent solenoid from the bracket, and then remove it from the vehicle.
To reinstall the vent solenoid, follow the steps for removal in reverse order.
Turn the ignition on and allow the engine to warm up for a few minutes. If the new vent solenoid is operating correctly, the "Service Engine Soon" warning should not be illuminated (or should go out after the engine has reached its programmed temperature).
