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Home >> Pontiac >> 2001 >> Aztek Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Inspection/Maintenance Procedures >> Inspection/Maintenance EGR Procedure >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform I/M system check. See INSPECTION/MAINTENANCE SYSTEM CHECK . After performing I/M system check, go to next step.
  2. Ensure vehicle is within the conditions for running this test. Turn off all accessories (e.g. A/C, blower fan, etc.). Start and operate engine at idle. In order for this test to run, vehicle must operate in the following conditions:
    • Accelerate at part throttle to 45 MPH and maintain this speed for one minute.
    • Make 4 decelerations of 25 seconds each from 45 MPH with throttle closed, no brake application, no manual downshift, with vehicle speed remaining at more than 25 MPH.
    • After each deceleration period, return vehicle speed to 45 MPH under part throttle acceleration and maintain speed for 15 seconds.
    Using scan tool, observe I/M system status display. If EGR system status updates to YES, go to step  5. If EGR system status does not update to YES, go to next step.
  3. Using scan tool, observe DTC information. If scan tool indicates any failed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If scan tool does not indicate any other DTCs, go to next step.
  4. Using scan tool, observe Not Ran Since Code Cleared display. Determine if DTC P0401, P0404, P0405 or P1404 has not run. Enter DTC number in the Specific DTC menu of scan tool. Operate vehicle within the conditions for running the DTC. Repeat procedure until scan tool indicates that diagnostic test has run. Repeat for any additional DTCs that have not run. Observe I/M System Status display. If EGR system status updates to YES, go to next step. If EGR system status does not update to YES, see DIAGNOSTIC AIDS .
  5. Using scan tool, observe emission related DTC portion of I/M system status display. If scan tool indicates any emission related DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, system is okay.
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