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Home >> Pontiac >> 2001 >> Firebird Formula, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 5.7L >> Diagnostic Tests >> DTC P1441: EVAP System Flow During Non-Purge >> Diagnostic Procedures

Diagnostic Procedures

  1. If powertrain diagnostic system check was performed, go to next step. If powertrain diagnostic system check was not performed, go to POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under DIAGNOSTIC SYSTEM TESTS. After performing powertrain diagnostic system check, go to next step.
  2. Check for additional DTCs. If DTCs P0443, P0449, P0452 or P0453 are also set, diagnose those DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTCs P0443, P0449, P0452 or P0453 are not also set, go to next step.
  3. Turn ignition on. Using scan tool, monitor Fuel Tank Pressure (FTP) sensor pressure. If FTP sensor is -0.5 to +0.5 in.H2O, go to step  5. If FTP sensor is not -0.5 to +0.5 in. H2O, go to next step.
  4. Raise and support vehicle. Locate and identify EVAP system components. See Figure. Disconnect FTP sensor connector. Using scan tool, monitor FTP sensor voltage. If FTP sensor is zero volts, go to step  6. If FTP sensor is zero volts, go to DTC P0453: FUEL TANK PRESSURE SENSOR CIRCUIT HIGH VOLTAGE .
  5. Disconnect EVAP pipe from EVAP canister purge solenoid. See Figure. Connect a vacuum gauge to EVAP pipe. Disconnect EVAP canister purge solenoid electrical connector. Monitor vacuum gauge readings. Start engine and increase idle to 1200-1500 RPM. If vacuum gauge indicates an increase in vacuum, go to step  7. If vacuum gauge does not indicate an increase in vacuum, go to DIAGNOSTIC AIDS .
  6. Check for damaged fuel tank wiring. Check condition of connector C405 located in front of rear axle. To identify connector C405, look for 3 connectors that plug into one connector. Repair as necessary. After repairs, go to step  9. If connections and wiring are okay, go to next step.
  7. Replace FTP sensor. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After repairs, go to step  9.
  8. Replace EVAP canister purge solenoid. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After repairs, go to next step.
  9. Using scan tool, review and record FREEZE FRAME and/or FAILURE RECORDS data. Clear DTCs. Perform service bay test. See SERVICE BAY TEST  under INSPECTION/MAINTENANCE PROCEDURES. If service bay test passes, go to next step. If service bay test does not pass, go to step  3.
  10. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no undiagnosed DTCs are displayed, system is okay.
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