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Home >> Pontiac >> 1996 >> Trans Sport >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P1441 - EVAP System Flow During Non-Purge >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform OBD-II System Check. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
  2. Turn ignition on, engine off. Using scan tool, read EVAP VACUUM SW. If scan tool displays NO PURGE, go to next step. If scan tool does not display NO PURGE, go to step 13).
  3. Turn engine on and allow it to idle. Using scan tool, read EVAP VACUUM SW. If scan tool displays NO PURGE, go to next step. If scan tool does not display NO PURGE, go to step 5).
  4. Turn ignition on, engine off. Using scan tool, read and record FAILS RECORD DATA. Operate vehicle within conditions noted in FAILED RECORDS DATA. Read SPECIFIC DTC. If scan tool displays DTC P1441 FAILED THIS IGN, go to next step. If scan tool does not display DTC P1441 FAILED THIS IGN, go to DIAGNOSTIC AIDS.
  5. Disconnect EVAP purge solenoid harness connector. Allow engine to idle. Read EVAP VACUUM SW. If scan tool displays NO PURGE, go to next step. If scan tool does not display NO PURGE, go to step 7).
  6. Turn ignition off. Disconnect PCM connectors. Check EVAP purge solenoid driver circuit for short to ground. If short to ground is found, repair as necessary and go to step 18). If no short is found, go to step 17).
  7. Leave EVAP purge solenoid harness connector disconnected. Disconnect vacuum signal hose from EVAP purge vacuum switch. Connect a vacuum gauge to signal hose. Allow engine to idle. If vacuum is more than 5 in H(2)O, go to next step. If vacuum is 5 in H(2)O or less, go to step 10).
  8. Check for incorrect vacuum hose routing or switched vacuum lines at EVAP purge solenoid. If a problem is found, go to step 17). If no problem is found, go to next step.
  9. Replace EVAP purge solenoid and go to step 17).
  10. Check EVAP purge hose for restriction between EVAP canister and vacuum switch. If restriction is found, repair as necessary and go to step 17). If no restriction is found, go to next step.
  11. Check fuel tank vapor line for restriction between EVAP canister and fuel tank. If restriction is found, repair as necessary and go to step 17). If no restriction is found, go to step 15).
  12. Disconnect EVAP vacuum switch harness connector. Connect a jumper wire across vacuum switch harness connector terminals. If scan tool displays NO PURGE, go to step 14). If scan tool does not display NO PURGE, go to next step.
  13. Check EVAP vacuum switch signal circuit for open or short to ground between EVAP vacuum switch and PCM. Check for open EVAP vacuum switch ignition feed circuit. Check for faulty signal circuit connection at EVAP vacuum switch. If problem is found, go to step 17). If no problem is found, go to step 16).
  14. Check for faulty connection at EVAP vacuum switch. If faulty connection is found, repair as necessary and go to step 17). If connection is okay, go to next step.
  15. Replace EVAP vacuum switch and go to step 17).
  16. Replace PCM. Replacement PCM requires special equipment for programming procedures. Go to next step.
  17. Read and record FAIL RECORDS data for DTC P1441. Operate vehicle within conditions noted in FAIL RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P1441 FAILED THIS IGN, return to step 2). If scan tool does not display DTC P1441 FAILED THIS IGN, repair is complete.
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