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Home >> Cadillac >> 2017 >> XT5 Base >> Repair and Diagnosis (Single Page) >> Electrical >> Charging Systems >> Battery, Charging System And Starting System >> Diagnostic Information and Procedures >> DTC P0621: Generator L-Terminal Circuit >> Circuit/System Verification
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Circuit/System Verification

  1. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  2. Verify the DTC does not set.
    • If the DTC sets 
    1. Verify the scantool parameter Generator L-Terminal Signal = 5-95 %
      • If the expected value 
    2. Disconnect the connector X1 while engine running
    • If not the expected value 
  3. Verify the scantool parameter Generator L-Terminal Signal = between 89 and 92 %
    • If not the expected value 
  4. Refer to Circuit/System Testing.
    • If the DTC does not set 
  5. All OK.
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