LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 57 (Engine Control System Self-Diagnostics - 3.1L Engine) >> Diagnostic Tests >> DTC P0446: EVAP Canister Vent Blocked >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix, 2002 Chevrolet Malibu, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Did DTC P0443, P0449, or P0453 set? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Inspect the Evaporative Emission (EVAP) system for a damaged EVAP vent valve, or a pinched EVAP vent hose. Did you find and correct the condition? If yes, go to step  15. If no, go to next step.
  4. With a scan tool, capture and record the Fail Record data and clear the DTCs. 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.
  5. Disconnect the purge line from the EVAP purge valve. Turn ignition on, with engine off. Observe the Fuel Tank Pressure (FTP) parameter with a scan tool. Does the scan tool indicate FTP about 0 in. H2O. If yes, go to next step. If no, go to step  9.
  6. Turn ignition off. Reconnect all previously disconnected hardware. Install the J-41415 Fuel Fill Cap Adaptor. Connect the J-41413 EVAP Pressure and Purge Station and the fuel fill cap to the J-41415. Turn ignition on, with engine off. Command the EVAP canister vent valve ON with a scan tool. DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results. Pressurize the EVAP system to 5 in. H2O with the J-41413. Rotate the J-41413 rotary switch to the OFF/HOLD position. Command the EVAP canister vent valve OFF with a scan tool. Does the scan tool indicate FTP about 0 in. H2O. If yes, go to step  11. If no, go to step  8.
  7. Disconnect the EVAP canister vent hose from the EVAP canister vent valve. Does the scan tool indicate FTP within -0.5 to 0.5 in. H2O? If yes, go to step  11. If no, go to next step.
  8. Disconnect the EVAP vent pipe from the EVAP canister. Does the scan tool indicate FTP about 0 in. H2O? If yes, go to step  14. If no, go to step  12.
  9. Observe the FTP sensor voltage with a scan tool. Is the FTP sensor voltage more than 4.3 volts? If yes, go to DTC P0453: FUEL TANK PRESSURE SENSOR CIRCUIT - HIGH VOLTAGE . If no, go to next step.
  10. Test for poor connections at the harness connector of the FTP sensor. Did you find and correct the condition? If yes, go to step  15. If no, go to step  13.
  11. Replace the EVAP canister vent valve. After repairs, go to step  15.
  12. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  13. Replace the FTP sensor. After repairs, go to step  15.
  14. Repair the blockage in the EVAP vent hose. After repairs, go to next step.
  15. With a scan tool, capture and record the Fail Record data and clear the DTCs. 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  5.
  16. Using scan tool, observe stored information and Capture Info. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other DTCs are displayed, system is okay.
scientia non olet · About LEMON Manuals