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Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 2 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P0440: Evaporative Emission System >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  1. If powertrain diagnostic system check was performed, go to next step. If powertrain diagnostic system check was not performed, go to POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under DIAGNOSTIC SYSTEM TESTS. After performing powertrain diagnostic system check, go to next step.
  2. If DTC P0443 or P0449 are also set, diagnose those DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTC P0443 or P0449 are not set, go to next step.
  3. Inspect EVAP system for the following conditions:
    • Loose, missing or damaged service port Schrader valve.
    • 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  19. If EVAP system is okay, go to next step.

  4. Using scan tool, perform EVAP system SERVICE BAY TEST. See SERVICE BAY TEST  under INSPECTION/MAINTENANCE PROCEDURES. If vehicle passes test, see DIAGNOSTIC AIDS . If vehicle fails test, go to next step.
  5. Remove fuel tank cap. Install Fuel Fill Cap Adapter (J 41415-40) to fuel filler neck. Connect EVAP Pressure/Purge Diagnostic Station (J 41413) to fuel fill cap adapter. Turn ignition on. Using scan tool, seal the EVAP system. Pressurize system to 5 in. H2O using EVAP pressure/purge diagnostic station. Rotate rotary switch on EVAP pressure/purge diagnostic station to OFF/HOLD position. Monitor pressure gauge for one minute. If pressure holds steady, go to next step. If pressure does not hold steady, go to step  9.
  6. Compare EVAP pressure/purge diagnostic station pressure gauge and FTP sensor reading on scan tool. If gauge and scan tool readings are approximately the same, go to next step. If gauge and scan tool readings are not approximately the same, go to step  13.
  7. Pressurize system to 5 in. H2O using EVAP pressure/purge diagnostic station. Rotate rotary switch on EVAP pressure/purge diagnostic station to OFF/HOLD position. Monitor pressure gauge for one minute. Using scan tool, command EVAP canister purge solenoid to 50 percent. If pressure decreases, go to next step. If pressure does not decrease, go to step  10.
  8. Check vacuum source hose to EVAP canister purge solenoid for blockage or leaks. See Figure. Repair as necessary. After repairs, go to step  19. If vacuum source hose is okay, go to DIAGNOSTIC AIDS .
    NOTE: In next step, to check for leaks at fuel fill hoses/pipes, fuel tanks may need to be lowered, but not disconnected. See REMOVAL, OVERHAUL & INSTALLATION - CARS article.
  9. Pressurize system to 5 in. H2O using EVAP pressure/purge diagnostic station. Check for leaks using Ultrasonic Leak Detector (J 41416). Check for leaks at the following areas: EVAP purge, vapor and vent hose/pipes, fuel fill hose/pipe, EVAP canister, EVAP canister vent and purge solenoids, fuel sender seals, fuel tank pressure valve and fuel fill limiter vent valve. See Figure and Figure . If leak is found and repaired, go to step  19. If no leaks are found, go to DIAGNOSTIC AIDS .
  10. Monitor pressure gauge. Disconnect EVAP purge pipe from EVAP canister purge solenoid. See Figure. If EVAP system pressure decreases, go to step  16. If EVAP system pressure does not decrease, go to next step.
  11. Monitor pressure gauge. Disconnect EVAP purge pipe from EVAP canister. If EVAP system pressure decreases, go to step  17. If EVAP system pressure does not decrease, go to next step.
  12. Monitor pressure gauge. Disconnect EVAP vapor line from EVAP canister. If EVAP system pressure decreases, go to step  18. If EVAP system pressure does not decrease, go to step  15.
  13. Using scan tool, monitor Fuel Tank Pressure (FTP) sensor voltage. If voltage is more than 4.3 volts, go to DTC P0453: FUEL TANK PRESSURE SENSOR CIRCUIT HIGH VOLTAGE . If voltage is less than 4.3 volts, go to next step.
  14. Replace FTP sensor. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After replacement, go to step  19.
  15. Repair pinched or obstructed EVAP vapor line. After repairs, go to step  19.
  16. Replace EVAP canister purge solenoid. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After replacement, go to step  19.
  17. Repair restriction in the EVAP purge pipe. After repairs, go to step  19.
  18. Replace EVAP canister. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After replacement, go to next step.
  19. Using scan tool, perform EVAP system SERVICE BAY TEST. See SERVICE BAY TEST  under INSPECTION/MAINTENANCE PROCEDURES. If test passes, go to next step. If test does not pass, go to step  2.
  20. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no undiagnosed DTCs are displayed, system is okay.
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