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Home >> Saturn >> 2000 >> LS2 Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0621: Generator "L" Terminal Circuit >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Turn ignition on, with engine off. Using a DVOM, check voltage on generator "L" terminal (Red wire). If voltage reading is greater than 1.6 volts, go to next step. If voltage reading is 1.0-1.6 volts, problem is intermittent. See DIAGNOSTIC AIDS . If voltage reading is less than one volt, check for open in Red wire between generator and ECM. Repair as necessary. If circuit is okay, check for terminal tightness at connectors. Repair as necessary. If terminals are okay, replace ECM.
  3. Connect test light between ground and generator "L" terminal circuit (Red wire). If test light illuminates, repair short to voltage in circuit (Red wire). If test light does not illuminate, check for terminal tightness at connectors. Repair as necessary. If circuit is okay, replace generator.
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