Functional Description - Vent Blocker Valve (VBV)
WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
The normally open Vent Blocker Valve (VBV), located between the Fuel Tank and Charcoal Canister, is used to manage pressure and vacuum in the Fuel Tank. When the VBV is closed it splits the Evaporative system into two separate sections that can be diagnosed during leak testing, the "fresh air side" and "fuel tank side".
- During normal engine operation the VBV is opened to relieve excess Fuel Tank pressure above approximately 35kPa (4.64psi) and excess vacuum below approximately -14.0kPa (-2.03psi).
The Powertrain Control Module (PCM) controls the VBV operation through a high side driver control.