Thermal Vacuum Valve - EVAP: Description and Operation

Thermal Vacuum Valve (TVV)

PURPOSE
The Thermal vacuum valve (TVV) controls canister purge operation based on coolant temperature.

OPERATION
Below 40°C (104°F) the TVV is closed forcing fuel vapors to be absorbed into the canister. Above 59°C (138°F) the TVV is opened allowing vacuum to flow through the TVV and purge the charcoal canister.