Locate the purge valve and disconnect the electrical connector
Inspect the valve and hoses for cracks, damage, or loose connections
Check the valve resistance with a multimeter against manufacturer specifications
Apply vacuum to the valve and verify it holds or opens as specified
Use a scan tool to command the purge valve on and off if available
Listen or feel for clicking when the valve is energized
Test for continuity in the wiring harness and connector
Check for power and ground at the connector with the ignition on
Verify the valve is not stuck open or stuck closed
Reinstall all connections and clear any diagnostic trouble codes after testing