EVAP Pressure/Purge Diagnostic Test Procedure

1. Make sure fuel level is less than 85% full. Drain tank until this level is reached.
2. Ignition On, engine Off.
3. Using Scan tool, command EVAP PURGE/SEAL On.
4. Connect the red hose form the EVAP Pressure/Purge Diagnostic Station to the EVAP service port. Be sure to finger tighten to prevent damage to the internal hose seal or EVAP service port.
5. Fully open the nitrogen cylinder valve.




6. Turn the control panel rotary valve to the pressure position.




7. Use the Ultrasonic Leak Detector to locate leak.
Common leak areas are shown in the diagram.

NOTE: The Ultrasonic Leak Detector should be held as close to the test area as safely possible. Check around all hoses and connections using a zig zag motion, carefully covering all suspected areas. If there is no ultrasonic sound present, the display will not show any lights. When an ultrasonic signal is detected, there will be an increase in the LED meter and an accompanying rushing sound in the audio headset. The sound will become more intense and the meter reading will increase as the instrument is drawn closer to the leak point.

8. Close the nitrogen valve.
9. Turn the rotary valve to the pressure release position.
10. Allow adequate time for the EVAP pressure gauge to return to 0 inches of H2O.
11. Turn the rotary valve to the Off/Hold position.
12. Disconnect the red hose from the EVAP service port.

NOTE: Do not attempt any fuel system or EVAP system servicing when the EVAP system is pressurized. The rotary valve must be in the Off/Hold position and all nitrogen pressure must be depleted from the EVAP system prior to removal of any fuel or EVAP system component.

13. Repair/replace any leaking components.
14. Recheck EVAP system for leaks once repair has been made.