Circuit/System Testing: Restriction

WARNING: This page is about a different car, the 2010 Saturn Outlook, 2010 GMC Acadia, 2010 Chevrolet Traverse, and 2010 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.

With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 %, the fuel tank vacuum should not increase to more than -15 mm Hg (-8 in. H2O).

If the fuel tank vacuum is greater than the specified value, isolate the restriction in the vent path by disconnecting one component at a time while the EVAP canister purge solenoid valve is commanded to 100 % and the vent valve is open.