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Home >> Chevrolet >> 1996 >> Astro Van Cargo, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P1441 - EVAP System Flow During Non-Purge >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform OBD-II System Check. Retrieve 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 SWITCH state. If scan tool displays ON, go to next step. If scan tool displays OFF, go to step 8).
  3. Disconnect EVAP vacuum switch hose (canister side). If scan tool displays ON, go to next step. If scan tool displays OFF, go to step 7).
  4. Disconnect EVAP vacuum switch harness connector. Connect a jumper wire across vacuum switch harness connector terminals. If scan tool displays OFF, go to step 17). If scan tool displays ON, go to next step.
  5. Using a DVOM, check voltage between engine ground and EVAP vacuum switch harness connector signal circuit. If voltage is about battery voltage, go to next step. If voltage is not about 12 volts, go to step 16).
  6. Connect a test light between battery voltage and EVAP vacuum switch harness connector ground circuit. If test light illuminates, go to step 8). If test light does not illuminate, go to step 12).
  7. Check EVAP canister vent and vent hose, and EVAP purge vacuum hose for restriction. If restriction is found, go to step 18). If no restriction is found, go to step 11).
  8. Turn ignition on, engine off. Using scan tool, command EVAP canister purge solenoid on and off while listening to solenoid . If solenoid clicks when commanded on and off, go to step 11). If solenoid does not click, go to next step.
  9. Disconnect EVAP purge solenoid harness connector. Connect a test light between engine ground and EVAP purge solenoid harness connector control circuit. If test light illuminates, go to step 10). If test light does not illuminate, go to step 13).
  10. Connect a test light across EVAP purge solenoid harness connector. Using scan tool, command solenoid on and off. If test light flashes on and off, go to step 14). If test light does not flash on and off, go to step 15).
  11. DTC is intermittent. Go to DIAGNOSTIC AIDS.
  12. Repair open in EVAP vacuum switch ground circuit and go to step 20).
  13. Repair open in EVAP canister purge solenoid ignition feed circuit and go to step 20).
  14. Replace faulty EVAP canister purge solenoid and go to step 20).
  15. Check EVAP canister purge solenoid control circuit for open or short to ground. If problem is found, go to step 18). If no problem is found, go to step 19).
  16. Check EVAP vacuum switch control circuit for short to ground. If problem is found, go to step 18). If no problem is found, go to step 19).
  17. Replace EVAP vacuum switch and go to step 20).
  18. Repair as necessary and go to step 20).
  19. Replace VCM. Replacement VCM requires special equipment for programming procedures. Go to next step.
  20. Using scan tool, select DTC, CLEAR INFO function. Start engine and allow it to reach operating temperature. Using scan tool, select DTC, SPECIFIC function and enter DTC P1441. Operate vehicle within conditions required to set DTC. If scan tool displays RAN AND PASSED, go to next step. If scan tool does not display RAN AND PASSED, return to step 2).
  21. Using scan tool, select Read and Record INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, diagnose affected DTCs. If no DTCs are displayed, system is okay.
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