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Home >> Chevrolet >> 2002 >> Chevy Express G2500, Van Passenger Extended, 5.7 R, L31/KL6 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 5.7L - Bi-Fuel >> Inspection/Maintenance Procedures >> Inspection/Maintenance Heated Oxygen Sensor/Oxygen Sensor System Set Procedure >> Diagnostic Procedure

Diagnostic Procedure

  1. If inspection/maintenance system check has been performed, go to next step. If inspection/maintenance system check has not been performed, go to INSPECTION/MAINTENANCE SYSTEM CHECK  . After performing inspection/maintenance system check, go to next step.
  2. Ensure vehicle is within CONDITIONS FOR RUNNING  . Turn off all accessories. Start engine and allow to idle. Road test vehicle. For this test to run, accelerate at part throttle to 45-55 MPH. Maintain this speed for 6 minutes or until I/M System Status updates to YES. Vehicles equipped with M/T (5 or 6 speed) may require operation in 4th or 5th gear respectively, for this test to run. Using scan tool, review I/M System Status display. Did the HO2S System Status update to YES? If yes, go to step  5 . If no, go to next step.
  3. Using scan tool, monitor DTC Information for both AF ECM and PCM. If scan tool indicates any failed DTC, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. If scan tool does not indicate any failed DTCs, go to next step.
  4. Using scan tool, monitor NOT RAN SINCE CODE CLEARED display. Determine which HO2S DTCs required for a YES status, have not run. Enter DTC number in SPECIFIC DTC menu of scan tool. Operate vehicle within CONDITIONS FOR RUNNING  . Repeat until scan tool indicates diagnostic test has run. Repeat for any additional required DTCs that have not run. Using scan tool, observe I/M System Status display. If HO2S System Status updates to YES, go to next step. If HO2S System Status does not update to YES, go to DIAGNOSTIC AIDS  .
  5. Using scan tool, monitor Emission Related DTC portion of I/M System Status display. Does scan tool indicate any emission related DTCs? If yes, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. If no, system is okay.
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