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Home >> Chevrolet >> 2000 >> Venture Plus >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0620: Generator Performance >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Start and operate engine at idle. Using scan tool, monitor generator. If scan tool indicates that generator is on, go to step  4. If scan tool does not indicate that generator is on, go to next step.
  3. Turn ignition on. Disconnect generator harness connector. Connect a DVOM between generator "L" terminal and a known-good ground. Start engine. Using scan tool, command generator on. Monitor voltage reading on DVOM. If voltage reading changes from zero to 5 volts, diagnose charging system. See appropriate STARTING & CHARGING SYSTEMS article. If voltage reading does not change from zero to 5 volts, go to next step.
  4. Check generator "L" circuit for open or short to ground. Repair as necessary. After repairs, go to step  8. If circuit is okay, go to next step.
  5. Check generator "L" circuit for short to voltage. Repair as necessary. After repairs, go to step  8. If circuit is okay, go to next step.
  6. Check for poor connection at PCM. Repair as necessary. After repairs, go to step  8. If connections are okay, go to next step.
  7. Replace PCM. program replacement PCM using required equipment. After replacing PCM, go to next step.
  8. Using scan tool, review and record scan tool FAIL RECORDS data. Clear DTCs. Operate vehicle within conditions for setting this DTC. Recheck DTCs. If this DTC resets, go to step  2. If this DTC does not reset, system is okay.
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