EVAP Pressure/Purge Diagnostic Cart Test Procedures

1. Be sure that fuel tank is 3/4 full or less. If fuel level is greater than 3/4, use Scan tool tank drain function or equivalent to drain fuel down to 3/4 full. (Refer to "Tank Drain Procedure" in "fuel system".)
2. Turn ignition to RUN position (engine Off).
3. Using Scan tool (EVAP System), command [1][2]EVAP vent solenoid On (closed).
4. Connect red hose from [1][2]EVAP Pressure/Purge Diagnostic Station to vehicle service port (on back of air cleaner box). Be sure to finger tighten to prevent damage to internal hose seal or service port.
5. Fully open nitrogen cylinder valve.
6. Turn control panel rotary valve to pressure position.
7. Use ultrasonic leak detector to locate leak.

NOTE: The ultrasonic leak detector should be held as close to 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, display will not show any lights. When an ultrasonic signal is detected, it will be indicated by an increase in LED meter and an accompanying translation in audio in headset. A leak will produce a rushing sound in headset. The sound will become more intense and meter reading will increase as instrument is drawn closer to leak point.

8. Close nitrogen cylinder valve.
9. Turn rotary valve to pressure Release position.
10. Allow adequate time for [1][2]EVAP pressure gauge to return to zero inches of H2O.
11. Turn rotary valve to Off/Hold position.
12. Disconnect red hose from service port.

CAUTION: Do not attempt any fuel system servicing when fuel system is pressurized. the rotary valve must be in off/hold position and all nitrogen pressure must be depleted from fuel system prior to removal of fuel cap or disassembly of any fuel system component.

13. Repair any leaking components.
14. Perform "EVAP System Check" to verify repair. Component Tests and General Diagnostics