LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2003 >> Venture Base, Van Cargo Extended >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0446: EVAP Emission Control System Vent Control Circuit >> Diagnostic Procedures

Diagnostic Procedures

  1. Did you perform the Diagnostic System Check - Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Observe the Freeze Frame/Failure Records for this DTC. Using scan tool, perform the Service Bay Test. Does the scan tool indicate that the Service Bay Test passed? If yes, go to DIAGNOSTIC AIDS . If no, go to next step.
  3. Inspect the EVAP system for the following conditions:
    • A damaged EVAP vent valve.
    • A pinched EVAP vent hose.

    Did you find and correct the condition? If yes, go to step  13. If no, go to next step.

  4. Turn ignition off. Disconnect the purge line from the EVAP purge solenoid. Turn ignition on, with engine off. Is the fuel tank pressure sensor parameter within -1 to 1 in. H2O? If yes, go to next step. If no, go to step  9.
    5. NOTE: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results.
  5. Turn ignition off. Reconnect all previously disconnected hardware. Install the Fuel Fill Cap Adapter (J-41415-40). Connect the EVAP Pressure/Purge Diagnostic Station (J-41413) and the vehicle fuel fill cap to the Fuel Fill Cap Adapter. Turn ignition on, with engine off. With a scan tool, seal the EVAP system. With the EVAP Pressure/Purge Diagnostic Station, pressurize the EVAP system to 5 in. H2O. Rotate the EVAP Pressure/Purge Diagnostic Station rotary switch to the OFF/HOLD position. Command the EVAP canister vent valve OFF with a scan tool. Does the scan tool indicate FTP near zero in. H2O? If yes, see DIAGNOSTIC AIDS . If no, go to next step.
  6. Disconnect the EVAP vent hose from the EVAP vent solenoid. Is the fuel tank pressure sensor parameter less than one in. H2O? If yes, go to step  11. If no, go to next step.
  7. Disconnect the EVAP vent hose from the EVAP canister. Is the fuel tank pressure sensor parameter less than one in. H2O? If yes, go to next step. If no, go to step  12.
  8. Repair the pinched or restricted EVAP vent hose. After repairs, go to step  13.
  9. Test for an intermittent and for a poor connection at the control module. Did you find and correct the condition? If yes, go to step  13. If no, go to next step.
  10. Replace FTP sensor. See REMOVAL & INSTALLATION - MONTANA, SILHOUETTE & VENTURE article. After replacing sensor, go to step  13.
  11. Replace EVAP vent solenoid. See REMOVAL & INSTALLATION - MONTANA, SILHOUETTE & VENTURE article. After repairs, go to step  13.
  12. Replace EVAP canister. See REMOVAL & INSTALLATION - MONTANA, SILHOUETTE & VENTURE article. After repairs, go to step  13.
  13. Perform the Service Bay Test. Does the scan tool indicate that the Service Bay Test passed? If yes, go to next step. If no, go to step  3.
  14. Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
scientia non olet · About LEMON Manuals