LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2018 >> Acadia Denali, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 321 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P0621: Generator L-Terminal Circuit >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
  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.
scientia non olet · About LEMON Manuals