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Home >> Oldsmobile >> 1997 >> Regency >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Systems Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0441 - EVAP System No Flow During Purge >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. See the BASIC TESTING - 3.8L article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
  2. Turn engine on and allow it to idle. Using scan tool, command EVAP purge solenoid on, while monitoring EVAP VACUUM SW on ENG 2 data list. If scan tool displays PURGE, go to next step. If scan tool does not display PURGE, go to step 4).
  3. Turn ignition on, engine off. Using scan tool, read and record FAIL RECORDS data for DTC P0441. Operate vehicle within conditions noted in FAIL RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0441 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0441 FAILED THIS IGN, see DIAGNOSTIC AIDS.
  4. Plug vacuum line between EVAP purge canister and EVAP vacuum switch. Turn engine on and allow it to idle. Using scan tool, command EVAP purge solenoid on, while monitoring EVAP VACUUM SW on ENG 2 data list. If scan tool displays PURGE, go to next step. If scan tool does not display PURGE, go to step 6).
  5. Check vacuum line to canister for damage or improper connections. If a problem is found, repair as necessary. After repairs, go to step 20). If no problem is found, go to step 14).
  6. Turn ignition off. Connect a vacuum gauge between EVAP purge solenoid and vacuum switch. Start engine and allow it to idle. Using scan tool, command EVAP purge solenoid on. If vacuum gauge reads 12 in. Hg, go to next step. If vacuum is not as specified, go to step 8).
  7. Turn ignition off. Disconnect vacuum switch harness connector. turn ignition on. Observe EVAP VACUUM SW. If scan tool displays PURGE, go to step 15). If scan tool does not display PURGE, go to step 9).
  8. Turn ignition off. Connect a vacuum gauge to EVAP purge solenoid vacuum source. Start engine and allow it to idle. If vacuum gauge reads 12 in. Hg, go to step 10). If vacuum is not as specified, go to step 16).
  9. Turn ignition off. Disconnect PCM connectors. Turn ignition on. Check for short to voltage in EVAP vacuum switch input circuit. If a problem is found, repair as necessary. After repairs, go to step 20). If no problem is found, go to step 19).
  10. Turn ignition off. Disconnect EVAP purge solenoid harness connector. Connect a test light across EVAP purge solenoid harness connector signal and ground circuits. Turn ignition on. Using scan tool, command EVAP solenoid on. If test light illuminates, go to step 17). If test light does not illuminate, go to next step.
  11. Turn ignition off. Disconnect PCM connectors. Connect a test light across EVAP purge solenoid harness connector signal and ground circuits. Turn ignition on. Connect a jumper wire between EVAP purge solenoid harness connector driver circuit and PCM harness connector ground circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 13).
  12. Check for faulty connection at PCM. If connection is faulty, repair as necessary. After repairs, go to step 20). If connection is okay, go to step 19).
  13. Repair EVAP purge solenoid ignition feed circuit for open or short to ground, or EVAP purge solenoid driver circuit for open. After repairs, go to step 20).
  14. Replace EVAP canister. After replacing canister, go to step 20).
  15. Replace EVAP vacuum switch. After replacing switch, go to step 20).
  16. Locate and repair cause of no vacuum. After repairs, go to step 20).
  17. Check for faulty connection at EVAP purge solenoid. If faulty connection is found, repair as necessary. After repairs, go to step 20). If connection is okay, go to next step.
  18. Replace EVAP purge solenoid. After replacing EVAP solenoid, go to step 20).
  19. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  20. Read and record FAIL RECORDS data for DTC P0441. Clear DTCs. Operate vehicle within conditions noted in FAIL RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P0441 FAILED THIS IGN, return to step 2). If scan tool does not display DTC P0441 FAILED THIS IGN, repair is complete.
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