Test Description
WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number in the diagnostic procedures.
- 4
This test determines if the EVAP canister purge valve can seal. Any indication of vacuum on the vacuum gage indicates that the EVAP purge valve is not seating properly.