Evaporative Emissions System: Service and Repair
TOOLS REQUIREDJ 41413 [1][2]EVAP Pressure/Purge Diagnostic Station
NOTE: Use the [1][2]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 DTC diagnostics lead to a no trouble found or to EVAP purge solenoid replacement, proceed with the following EVAP canister diagnostics.
1. Remove the EVAP canister purge solenoid valve.
2. Lightly tap the EVAP canister purge solenoid on a clean work area.
3. Look for carbon particles or carbon dust exiting from either of the vacuum ports.
^ Reinstall the EVAP purge solenoid if no carbon release is evident. Continue with the published service manual DTC procedures.
^ Continue with this service procedure if carbon is being released from the EVAP purge solenoid.
4. Remove the EVAP canister from the vehicle.
5. Turn off the main cylinder valve (1) on the J 41413 [1][2]EVAP purge/pressure diagnostic station.
6. Disconnect the black hose (4) that connects the nitrogen cylinder to the J 41413 cart at the pressure regulator (5) by unscrewing the knurled nut on the regulator.
7. Connect a section of vacuum hose to the open fitting of the J 41413 pressure regulator (5).
8. Disconnect the engine compartment [1][2]EVAP pipe (5) at the chassis EVAP purge pipe (4)
9. Connect the other end of the vacuum hose to the chassis [1][2]EVAP purge pipe (4).
10. Turn on the main nitrogen cylinder valve.
11. Continue to blow any debris from the purge pipe for 15 seconds.
12. Return the J 41413 [1][2]EVAP purge/pressure diagnostic station to its original condition by re-installing the black hose disconnected in step 6.
13. Replace the EVAP canister purge solenoid valve.
14. Replace the EVAP canister.
15. Connect the J 41413 [1][2]EVAP purge/pressure diagnostic station to the vehicle EVAP service port.
16. Turn the 4 position switch to Purge.
17. Idle the engine at the normal operating temperature.
18. Open the throttle until engine speed reaches 2000 RPM.
19. Observe the H2O vacuum gauge on the [1][2]EVAP cant. The vacuum should read greater than 15 in. H2O.
^ Check the vacuum supply to the EVAP purge solenoid valve if the vacuum is less than 15 in. H2O.
^ Continue with the published service diagnostics if the vacuum is greater than 15 in. H2O.