LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 26 (Engine Controls Self-Diagnostics - 5.0L & 5.7L) >> Diagnostic Tests >> DTC P0446: EVAP Vent Valve Performance >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2001 GMC Savana, 2001 Chevrolet RV Cutaway, 2001 Chevrolet Cutaway, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. If scan tool indicates DTC P0443, P0449, P0452, or P0453 are also set, see DTC P0443: EVAP PURGE SOLENOID CONTROL CIRCUIT , DTC P0449: EVAP VENT SOLENOID CONTROL CIRCUIT , DTC P0452: FUEL TANK PRESSURE SENSOR - LOW VOLTAGE  or DTC P0453: FUEL TANK PRESSURE SENSOR - HIGH VOLTAGE  . If scan tool does not indicate DTCs P0443, P0449, P0452, or P0453 are also set, go to next step.
  3. Inspect EVAP system for a damaged EVAP vent valve and a pinched EVAP vent hose. See COMPONENT LOCATIONS . If problem was found, repair as necessary. After repairs, go to step  14. If problem was not found, go to next step.
    4. NOTE: SERVICE BAY TESTS are available with Tech 2 scan tool and may not be available with after market scan tools.
  4. Using scan tool, capture and record FREEZE FRAME/FAILURE RECORDS data and clear DTCs. Using scan tool, perform SERVICE BAY TEST in SPECIAL FUNCTIONS menu. If scan tool indicates service bay test passed, see DIAGNOSTIC AIDS . If scan tool did not indicate service bay test passed, go to next step.
  5. Disconnect purge line from EVAP purge valve. Turn ignition on, engine off. Using scan tool, observe Fuel Tank Pressure (FTP) parameter. If scan tool indicates FTP is about zero in. H2O, go to next step. If scan tool does not indicate FTP is about zero in. H2O, go to step  8.
    6. NOTE: Always zero EVAP pressure and vacuum gages on EVAP pressure/purge diagnostic station before proceeding with diagnosis.
  6. Turn ignition off. Install Fuel Tank Cap Adaptor (J 41415-40). Connect Pressure/Purge Diagnostic Station (J 41413) and vehicle fuel fill cap to fuel tank cap adaptor. Reconnect all previously disconnected hardware. Turn ignition on, engine off. Using scan tool, seal EVAP system. Using pressure/purge diagnostic station, pressurize EVAP system to 5 in. H2O. Turn pressure/purge diagnostic station rotary valve to OFF/HOLD position. Disconnect EVAP vent hose from EVAP vent valve. If scan tool indicates fuel tank pressure is about zero in. H2O, go to step  10. If scan tool does not indicate fuel tank pressure is about zero in. H2O, go to next step.
  7. Disconnect EVAP vapor pipe from EVAP canister. If scan tool indicates fuel tank pressure is about zero in. H2O, go to step  13. If scan tool does not indicate fuel pressure is about zero in. H2O, go to step  11.
  8. Using scan tool, observe FTP sensor voltage. If FTP sensor voltage is more than 4.3 volts, see DTC P0453: FUEL TANK PRESSURE SENSOR - HIGH VOLTAGE . If FTP sensor voltage is not more than 4.3 volts, go to next step.
  9. Check FTP sensor connector for poor connections. If problem was found, repair as necessary. After repairs, go to step  14. If problem was not found, go to step  12.
  10. Replace EVAP vent valve. After repairs, go to step  14.
  11. Replace EVAP canister. After repairs, go to step  14.
  12. Replace FTP sensor. After repairs, go to step  14.
  13. Repair blockage in EVAP vent hose. After repairs, go to next step.
  14. Reconnect all EVAP hardware that was previously disconnected. Using scan tool, perform SERVICE BAY TEST. If scan tool indicates SERVICE BAY TEST passed, go to next step. If scan tool does not indicate SERVICE BAY TEST did not pass, go to step  3.
  15. Using scan tool, observe stored information. If scan tool displays any DTCs that have not been diagnosed, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If scan tool does not display any DTCs, system is okay.
scientia non olet · About LEMON Manuals