Test NTC-6: Checking Evaporative Emissions System

NOTE: For circuit identification, see WIRING DIAGRAMS article. After each repair procedure has been completed, reconnect all components. Perform TEST VER-5 to ensure system is functioning properly. Ensure no DTCs are present before performing this test.

Evaporative canister is located on top of fuel tank. See Figure. It may be necessary to lower or remove fuel tank to access to EVAP canister. Check EVAP canister for damage or any signs of fuel inside of canister. If any fuel is present, fuel tank rollover valve may be defective. If EVAP canister is not damaged and no signs of fuel entering EVAP canister exists, go to next step. If EVAP canister is damaged or signs of fuel entering EVAP canisters exist, repair or replace EVAP canister as necessary.
Inspect EVAP purge hose that goes from EVAP canister to fuel tank. Check hose for being ripped, restricted or showing signs of dry rotting. If EVAP purge hose is okay, go to next step. If EVAP purge hose is defective, repair or replace EVAP purge hose as necessary.
Inspect EVAP purge hose that goes from EVAP purge solenoid to EVAP canister. Check hose for being ripped, restricted or showing signs of dry rotting. EVAP purge solenoid is located at right front corner of engine compartment, near air cleaner. See Figure. If EVAP purge hose is okay, go to next step. If EVAP purge hose is defective, repair or replace EVAP purge hose as necessary.
Inspect vacuum supply hose between EVAP purge solenoid and throttle body for proper routing and for being ripped, restricted or showing signs of dry rotting. Inspect vacuum supply hose fitting on throttle body for restrictions or signs of damage. If vacuum supply hose and fitting on throttle body are okay, go to next step. If vacuum supply hose is defective or fitting on throttle body is damaged or restricted, repair or replace components as necessary.
Ensure vacuum supply hose and EVAP purge hose are disconnected at EVAP purge solenoid. Using vacuum pump, apply 10 in. Hg of vacuum to vacuum supply hose fitting on EVAP purge solenoid and see if EVAP purge solenoid holds vacuum. If EVAP purge solenoid holds vacuum, go to next step. If EVAP purge solenoid does not hold vacuum, replace EVAP purge solenoid.
Using vacuum pump, apply 10 in. Hg of vacuum to vacuum supply hose fitting on EVAP purge solenoid. Turn ignition on. Using scan tool, actuate EVAP purge solenoid and monitor vacuum reading on vacuum pump. If vacuum decreases when EVAP purge solenoid is actuated, no problem is indicated at this time. Test is complete. If vacuum does not decrease when EVAP purge solenoid is actuated, replace EVAP purge solenoid.