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Home >> Cadillac >> 2017 >> CTS Base, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 129 (Power Door Lock System And Release Systems) >> Diagnostic Information and Procedures >> Trunk Release Malfunction >> Circuit/System Testing >> Release Actuator Inoperative
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Release Actuator Inoperative

WARNING: This page is about a different car, the 2016 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
  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 X3 harness connector at the X53A Fuse Block-Rear Body. It may take up to 2 minutes for all vehicle systems to power down
  6. Test for less than 10 Ω between the ground circuit terminal 12 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 
  7. Ignition ON
  8. 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 
  9. Connect a 10 A fused jumper wire between the control circuit terminal 8 and B+.
  10. Verify the M40 Rear Compartment Lid Latch activates.
    • If the M40 Rear Compartment Lid Latch is not activated 
    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 
  11. Ignition OFF, connect the X3 harness connector at the X53A Fuse Block-Rear Body. 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 X3 harness connector at the X53A Fuse Block-Rear Body.
    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 X53A Fuse Block-Rear Body.
    • If the M40 Rear Compartment Lid Latch is not activated 
  13. Connect a 3 A 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 X3 harness connector at the X53A Fuse Block-Rear Body, 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 X53A Fuse Block-Rear Body.
    • If the M40 Rear Compartment Lid Latch activates 
  15. Replace the K9 Body Control Module.
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