Evaporative Emissions System: Testing and Inspection

EVAP THERMAL VACUUM VALVE (EVAP TVV) CHECK

EVAP TVV Removal:

1. Remove EVAP TVV.
2. Connect length of vacuum hose to a port on the switch.

EVAP TVV Testing:

3. Place in water with temperature below 35°C (95°F).
4. Blow into valve, no air should pass through valve.

EVAP TVV Removal:

5. Heat water to a temperature above 54°C (129°F).
6. Blow into valve, air should pass through valve. If the TVV fails the above test, replace the valve.

Canister Valve:

EVAP CANISTER VALVE CHECK

The following checks will determine if the valve located on top of canister is operating properly.

1. Using a small length of vacuum hose connected to the TANK tube, blow into the canister. Air should escape through the PURGE tube and AIR tube at the bottom of canister.
2. Repeat the above test to the PURGE tube. Air should not escape any of the other tubes. If the valve on the canister fails the above test, the canister should be replaced.