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Home >> Buick >> 2014 >> Verano Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 37 (Power Door Lock System And Release Systems) >> Diagnostic Information and Procedures >> Trunk Release Malfunction >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2012 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.

Trunk Release Switch Inoperative

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S58 rear compartment lid unlatch switch. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal 1 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Verify the scan tool Trunk Lid/Liftgate Window Exterior Unlatch Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the harness connector at the K9 body control module.
    2. Test for infinite resistance between the signal circuit terminal 3 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 body control module.
    • If Inactive 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 1.
  6. Verify the scan tool Trunk Lid/Liftgate Window Exterior Unlatch Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. 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, replace the K9 body control module.
    • If Active 
  7. Test or replace the S58 rear compartment lid unlatch switch.

Release Actuator Inoperative

  1. Ignition OFF and all vehicle systems OFF, disconnect the KR95B rear compartment lid unlatch relay. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal 85 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    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. Ignition OFF.
    2. 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,
    3. Disconnect the harness connector at the M40 rear compartment lid latch.
    4. Test for infinite resistance between the control circuit terminal 30 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the KR95B rear compartment lid unlatch relay
    • If the test lamp illuminates 
  5. Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
  6. Verify the test lamp briefly turns ON when commanding the Trunk Lid Unlatch with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the harness connector at the K9 body control module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 body control module.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If the test lamp turns ON and OFF 
  7. Verify that a test lamp does not illuminate between the control circuit terminal 30 and ground.
    • If the test lamp illuminates 

      Repair the short to voltage on the control circuit

    • If the test lamp does not illuminate 
  8. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M40 rear compartment lid latch. It may take up to 2 minutes for all vehicle systems to power down.
  9. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  10. Connect the harness connector at the M40 rear compartment lid latch
  11. Ignition ON, connect a 10 A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30.
  12. Verify the M40 rear compartment lid latch is activated.
    • If the M40 rear compartment lid latch does not activate 
    1. Ignition OFF, disconnect the harness connector at the M40 rear compartment lid latch.
    2. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M40 rear compartment lid latch.
    • If the M40 rear compartment lid latch activates 
  13. Test or replace the KR95B rear compartment lid unlatch relay.
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