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Circuit/System Testing

WARNING: This page is about a different car, the 2021 Buick Envision. However, it is still accessible from the selected car via links, so may be relevant.
  1. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the B71R Liftgate Side Sensor-Right.
  2. Verify a test lamp illuminates between low reference terminal 2 and B+.
    • If the test lamp does not illuminate 
    1. Test circuit 4656 for an open/high resistance.
      • If an open/high resistance is found, repair the fault on the circuit.
      • Go to next step: If an open/high resistance is not found.
    2. Replace the K194 Rear Gate Module.
    • Go to next step: If the test lamp illuminates 
  3. Disconnect the harness connector at the B71L Liftgate Side Sensor - Left.
  4. Ignition ON, test for 4.8 - 5.2 V between the 5 V reference circuit terminal 1 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the K194 Rear Gate Module.
    2. Test for infinite resistance between the 5 V reference circuit 4654 and ground
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K194 Rear Gate Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the harness connector at the K194 Rear Gate Module, Ignition ON.
    2. Test for less than 1 V between the 5 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K194 Rear Gate Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Test for less than 2 Ω between the signal circuit terminal 1 and the signal circuit terminal 2 @ signal circuit 4655
    • If 2 Ω or greater 

      Replace the signal circuit 4655.

    • Go to next step: If less than 2 Ω 
  6. Test or replace the appropriate B71 Liftgate Side Sensor
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