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Home >> Buick >> 2016 >> Envision >> Repair and Diagnosis >> External Pages >> Different car >> Section 14 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P0625 or P0626: Generator F-Terminal >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2015 Buick LaCrosse. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify a test lamp illuminates between the G13 Generator B+ circuit terminal A X2, B X2 or 1 X2, and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Disconnect the B+ cable at the G13 Generator.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the G13 Generator.
    • If the test lamp illuminates 
  2. Ignition OFF, disconnect the X1 harness connector at the G13 Generator.
  3. Verify the scan tool ECM Generator F-Terminal Signal parameter is less than 5%.
    • If 5% or greater 
    1. Ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 2 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • If less than 5% 
  4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and B+.
  5. Verify the scan tool ECM Generator F-Terminal Terminal Signal parameter is greater than 95%.
    • If 95% or less 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω
    3. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If greater than 95%. 
  6. Replace the G13 Generator.
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