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Home >> Cadillac >> 2015 >> XTS Base >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Power Door Lock System And Release Systems >> Diagnostic Information and Procedures >> Trunk Release Malfunction >> Circuit/System Testing
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Circuit/System Testing

Exterior Trunk Release Switch Inoperative

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S58A Rear Compartment Lid Unlatch Switch-Exterior. 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 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 
  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 1 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 1 and the ground circuit terminal 2.
  6. Verify the scan tool Trunk Lid/Liftgate Window Exterior Unlatch Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, remove the 3 A fused jumper wire, 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 S58A Rear Compartment Lid Unlatch Switch-Exterior.

Interior Trunk Release Switch Inoperative

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S58B Rear Compartment Lid Unlatch Switch-Interior. 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 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 
  3. Ignition ON.
  4. Verify the scan tool Interior Liftgate/Liftgate Window 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 1 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 1 and the ground circuit terminal 2.
  6. Verify the scan tool Interior Liftgate/Liftgate Window Unlatch Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, remove the 3 A fused jumper wire, 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 S58B Rear Compartment Lid Unlatch Switch-Interior.

Release Actuator Inoperative

  1. 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.
  2. 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 
  3. Connect a test lamp between the control circuit terminal 1 and ground, ignition ON.
  4. Verify the test lamp does not turn ON and OFF when commanding the Trunk Lid Unlatch with a scan tool.
    • If the test lamp turns ON and OFF 

      Test or replace the M40 Rear Compartment Lid Latch.

    • If the test lamp does not turn ON and OFF 
  5. Ignition OFF, connect the harness connector at the M40 Rear Compartment Lid Latch. Disconnect the X2 harness connector at the X50A Fuse Block-Underhood, ignition ON.
  6. Verify the M40 Rear Compartment Lid Latch is not activated.
    • If the M40 Rear Compartment Lid Latch is activated 
    1. Ignition OFF, disconnect the harness connector at the M40 Rear Compartment Lid Latch, ignition ON.
    2. Test for less than 1 V between the control circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, test or replace the M40 Rear Compartment Lid Latch.
    • If the M40 Rear Compartment Lid Latch is not activated 
  7. Connect a 10 A fused jumper wire between the control circuit terminal 30 and B+.
  8. Verify the M40 Rear Compartment Lid Latch activates.
    • If the M40 Rear Compartment Lid Latch does not activate 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the M40 Rear Compartment Lid Latch, ignition ON.
    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, test or replace the M40 Rear Compartment Lid Latch.
    • If the M40 Rear Compartment Lid Latch activates 
  9. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the X50A Fuse Block-Underhood. It may take up to 2 minutes for all vehicle systems to power down.
  10. Test for less than 10 Ω between the ground circuit terminal 71 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 
  11. Ignition OFF, connect the X1 and X2 harness connector at the X50A Fuse Block-Underhood. Disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
  12. Verify the M40 Rear Compartment Lid Latch is not activated.
    • If the M40 Rear Compartment Lid Latch is activated 
    1. Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block-Underhood.
    2. Test for less than 1 V between the K9 Body Control Module control circuit terminal 11 X5 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the X50A Fuse Block-Underhood.
    • If the M40 Rear Compartment Lid Latch is not activated 
  13. Connect a 3A fused jumper wire between the control circuit terminal 11 and B+.
  14. Verify the M40 Rear Compartment Lid Latch activates.
    • If the M40 Rear Compartment Lid Latch does not activate 
    1. Ignition OFF, remove the jumper wire, disconnect the X2 harness connector at the X50A Fuse Block-Underhood, ignition ON.
    2. Test for infinite resistance between the K9 Body Control Module control circuit terminal 11 X5 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 X50A Fuse Block-Underhood.
    • If the M40 Rear Compartment Lid Latch activates 
  15. Replace the K9 Body Control Module.
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