Functional Test of EVAP Components

EVAP Charcoal Canister Vacuum Hose Routing:

FUNCTIONAL TEST
Disconnect the vacuum, tank and canister hoses from the Tank Pressure Control Valve (TPCV). Attach a hose to the fuel tank port of the TPCV and attempt to blow through it. Little or no air should pass through the TPCV.

With a hand vacuum pump, apply vacuum (15 inch Hg. or 51 kPa) through the TPCV upper tube (manifold vacuum supply port). If the vacuum reading is less than 10 inch Hg. after 10 seconds, the diaphragm is leaking and the TPCV must be replaced.

If the diaphragm holds vacuum, try to blow through the hose connected to the lower tube while vacuum is still being applied. An increased flow of air should be observed. If not, replace the TPCV.

Attach a hose to the fuel vapor port (from fuel tank) of the canister and attempt to blow through it. Air should pass into canister. If not, replace the canister.

Disconnect the EVAP solenoid electrical connector, attach a hose to the upper port of the canister, and attempt to blow through it. Air should not pass into the canister. If air passes, replace the canister.

Reconnect all purge hoses and the solenoid electrical connector.