Tools Required

J 41413 EVAP Pressure/Purge Diagnostic Station

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.

Important: Whenever the evaporative emissions (EVAP) DTC diagnostics lead to a no trouble found or to an EVAP purge solenoid replacement, proceed with the following EVAP canister diagnostics.

1. Remove the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
2. Lightly tap the EVAP purge solenoid on a clean work area.
3. Look for carbon particles or for carbon dust that is exiting from either of the vacuum ports.

•	If no carbon release is evident, re-install the purge solenoid. Continue with the published service manual DTC procedures.

•	If carbon is released from the purge solenoid, continue with this service procedure.

4. Remove the EVAP canister from the vehicle. Refer to Evaporative Emission Canister Replacement .
5. Turn OFF the main cylinder valve (1) on the J 41413 EVAP pressure/purge diagnostic station.
6. Disconnect the black hose (4) that connects the nitrogen cylinder to the cart J 41413 at the pressure regulator (5) by unscrewing the knurled nut on the pressure regulator.
7. Connect a section of the vacuum hose to the open fitting of the J 41413 pressure regulator (5).
8. Connect the other end of the vacuum hose to the engine compartment EVAP purge pipe.
9. Turn ON the main nitrogen cylinder valve (1).
10. Continue to blow any debris from the purge pipe for 15 seconds.
11. Return the J 41413 to its original condition by re-installing the black hose (4) that you disconnected in step 6.
12. Replace the EVAP canister purge solenoid valve with the new component. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
13. Replace the EVAP canister with the new component. Refer to Evaporative Emission Canister Replacement .



14. Connect the J 41413 to the vehicle EVAP service port.
15. Turn the 4-position switch to Purge.
16. Idle the engine at the normal operating temperature.
17. Open the throttle until the engine speed reaches 2000 RPM.
18. Observe the H2O vacuum gauge on the EVAP cart. The vacuum should read more than 15 inches H2O.

•	If the vacuum is less than 15 inches H2O, check the vacuum supply to the EVAP purge solenoid valve.

•	If the vacuum is more than 15 inches H2O, continue with the published service diagnostics.