Purge Control Diaphragm Valve and Thermosensor
- With engine cold, there should be continuity across the terminals of thermosensor. Disconnect upper hose at purge control valve on canister. Connect a vacuum gauge to hose and start engine. No vacuum should be present.
- With engine at normal operating temperature, disconnect upper hose from purge control valve. Connect a vacuum gauge and start engine. Vacuum should appear on gauge. If not, check thermosensor or solenoid valve (in emission control box, left side of back row).
Courtesy of AMERICAN HONDA MOTOR CO., INC.