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Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 7 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P0442: Evaporative Emission (EVAP) System Small Leak Detected ("Y" Body) >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. If any other EVAP system DTCs are present, go to applicable DTC. If no other EVAP system DTCs are present, go to next step.
  3. Inspect EVAP system for the following conditions:
    • Loose, incorrect, defective or missing fuel filler cap.
    • Improperly routed, kinked or damaged EVAP system chassis purge line from vacuum source in engine compartment.
    • Damaged EVAP purge solenoid valve.
    • Improperly routed, kinked or damaged EVAP system chassis purge line from EVAP purge solenoid valve to EVAP canister.
    • Leaking fuel tank vent valve.

    Repair EVAP system as necessary. After repairs, go to step 24. If EVAP system is okay, go to next step.

  4. Using scan tool, perform EVAP system SERVICE BAY TEST. If test passes (scan tool indicates 0.7-2.5 volts), see DIAGNOSTIC AIDS . If test does not pass, go to next step.
  5. Turn ignition on, with engine off. Remove fuel tank cap. Using scan tool, monitor fuel tank pressure. If fuel tank pressure is about zero in. Hg, go to next step. If fuel tank pressure is not about zero in. Hg, go to step  7.
  6. Using scan tool, clear DTCs. Install fuel tank cap. Start and operate engine at idle. Using scan tool, command EVAP purge solenoid valve to 50 percent. Monitor fuel tank pressure. If fuel tank pressure changes when solenoid is enabled, go to step  8. If fuel tank pressure does not change when solenoid is enabled, go to next step.
  7. Turn ignition on, with engine off. Remove fuel tank pressure sensor, located on top of right fuel tank. Connect an hand-held vacuum pump to vacuum port of fuel tank pressure sensor. Apply 10 in. Hg. Monitor fuel tank pressure sensor parameter using scan tool. If parameter changes as vacuum is applied, go to next step. If parameter does not change as vacuum is applied, go to step  23.
  8. Turn ignition off. Remove EVAP purge line from EVAP purge solenoid valve. Connect vacuum pump to EVAP purge solenoid valve vacuum port. Attempt to apply 10 in. Hg. If specified vacuum can be obtained, go to next step. If specified vacuum cannot be obtained, go to step  19.
  9. Connect vacuum gauge to EVAP purge solenoid valve. Start engine. Using scan tool, command EVAP purge solenoid valve to 50 percent. If vacuum gauge reading is 12 in. Hg or greater, go to step  11. If vacuum gauge reading is not 12 in. Hg or greater, go to next step.
  10. Turn ignition off. Remove vacuum source line from EVAP purge solenoid valve. Connect vacuum gauge to vacuum source. Start engine. If vacuum reading is 12 in. Hg or greater, go to step  19. If vacuum reading is not 12 in. Hg, go to step  18.
  11. Reconnect all EVAP components. Connect EVAP Pressure/Purge Diagnostic Station (J-41413) to EVAP system service port. Command EVAP vent valve on (closed) using scan tool. Continuously attempt to pressurize EVAP system leaving the diagnostic station knob in PRESSURIZE position. Using Ultrasonic Leak Detector (J-41416), attempt to locate EVAP system leak. Repair as necessary. After repairs, go to step  24. If no leaks are found, go to next step.
  12. Turn ignition off. Disconnect EVAP station. Disconnect vent line at EVAP vent valve, located near right fuel tank). Disconnect chassis EVAP purge pipe at EVAP canister nylon purge pipe. Connect vacuum pump to chassis EVAP purge pipe. Attempt to apply 5 in. Hg vacuum to EVAP canister. If vacuum can be obtained and held, go to next step. If vacuum cannot be obtained or held, go to step  22.
  13. Disconnect fuel tank vapor line from EVAP canister. Plug canister port for fuel tank vapor tank vapor line. Disconnect EVAP purge line from EVAP canister. Connect vacuum pump to EVAP purge port on EVAP canister. Turn ignition on. Using scan tool, command EVAP vent valve on (closed). Attempt to apply 5 in. Hg. If vacuum can be obtained, go to step  16. If vacuum cannot be obtained, go to next step.
  14. Leave system connected as in previous step. Disconnect vent line from EVAP vent valve. Plug vent line. Attempt to apply 5 in. Hg. If vacuum can be obtained, go to step  20. If vacuum cannot be obtained, go to next step.
  15. Check EVAP vent line from canister to EVAP vent valve for damage or leaks. Check EVAP canister purge nylon pipe or damage or leaks. Check for missing or damaged "O" rings. Repair as necessary. After repairs, go to step  24. If no problem is found, go to step  21.
  16. Check for loose clamps, kinked lines, disconnected or damaged hoses, pipes or components. Check for damaged or mission "O" ring seals. Remove both fuel tanks. Perform fuel tank leak test. Repair as necessary. After repairs, go to step  24. If no problem is found, go to next step.
  17. Check EVAP components or pipes for restrictions. Repair as necessary. After repairs, go to step  24. If no restriction is found, go to step  2.
  18. Repair vacuum source to EVAP purge solenoid valve. After repairs, go to step  24.
  19. Replace EVAP purge solenoid valve. After repairs, go to step  24.
  20. Replace EVAP vent valve. After replacing vent valve, go to step  24.
  21. Replace EVAP vapor canister. After replacing vapor canister, go to step  24.
  22. Replace EVAP line from EVAP purge solenoid valve to canister. After replacing line, go to step  24.
  23. Replace fuel tank pressure sensor. After replacing sensor, go to step  24.
  24. Using scan tool, perform EVAP system SERVICE BAY TEST. If test passes, go to next step. If test does not pass, go to step  5.
  25. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test. If no undiagnosed DTCs are displayed, system is okay.
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