Tools Required

Whenever the diagnostics lead to a no trouble found or an evaporative emission (EVAP) canister purge valve replacement, proceed with the following EVAP canister diagnostic.

1. Turn OFF the ignition.

Notice: Use the EVAP Pressure/Purge Diagnostic Station J 41413 in order to provide a clean, dry, low pressure gas source. Do not substitute any other pressurized gas source. Damage may result to the EVAP system.

2. Remove the EVAP canister purge valve from the vehicle. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
3. Lightly tap the EVAP canister purge valve on a hard surface.
4. Visually inspect for carbon particles exiting from either of the vacuum ports.
5. If no carbon particle release is evident, reinstall the valve. The procedure is complete.
6. If carbon particles have been released, the EVAP canister is faulty and the purge lines must be cleared.
7. Remove the EVAP canister from the vehicle. Refer to Evaporative Emission Canister Replacement .
8. Turn OFF the main cylinder valve (1) on the J 41413 EVAP purge/pressure diagnostic station.
9. Disconnect the black hose (4) that connects to the pressure regulator valve (5) of the nitrogen cylinder (3) on the EVAP cart.
10. Using a section of vacuum hose, connect one end onto the open fitting of the pressure regulator valve (5).
11. Connect the other end of the vacuum hose to the EVAP purge line on the vehicle.
12. Turn ON the main nitrogen cylinder valve (1) in order to blow out any charcoal particles and foreign material.
13. Continue to blow any debris from the purge line for 15 seconds.
14. Remove the vacuum hose from the vehicle purge line and return the J 41413 EVAP purge/pressure diagnostic station to its original condition as in step 9.
15. Install a new EVAP canister purge solenoid valve.
16. Install a new EVAP canister.
17. Connect the J 41413 EVAP purge/pressure diagnostic station to the vehicle and test the EVAP system for leaks with the J 41416 ultrasonic leak detector. Repair any leaks as necessary.