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Circuit/System Testing

  1. Ignition/Vehicle Off and all vehicle systems Off. Disconnect the X2 harness connector at the K39 Liftgate Control Module. 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 6 and ground.
    • If 10 Ω or greater 
    1. Ignition/Vehicle 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.
    • Go to next step: If less than 10 Ω 
  3. Ignition On/Vehicle in Service Mode.
  4. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition/Vehicle 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/Vehicle 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, replace the K39 Liftgate Control Module.
    • Go to next step: If the test lamp illuminates 
  5. Ignition/Vehicle Off and all vehicle systems Off. Connect the X2 harness connector at the K39 Liftgate Control Module. Disconnect the harness connector at the A23C Liftgate Latch Assembly. It may take up to 2 minutes for all vehicle systems to power down.
  6. Test for less than 10 Ω between the low reference circuit terminal 6 and ground.
    • If 10 Ω or greater 
    1. Disconnect the harness connector at the K39 Liftgate Control Module.
    2. Test for less than 2 Ω in the low 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 K39 Liftgate Control Module.
    • Go to next step: If less than 10 Ω 
  7. Ignition On/Vehicle in Service Mode.
  8. Verify the scan tool Liftgate Latch Pawl Switch parameter is Closed.
    • If not Closed 
    1. Ignition/Vehicle Off. Disconnect the harness connector at the K39 Liftgate 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 K39 Liftgate Control Module.
    • Go to next step: If Closed 
  9. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 6.
  10. Verify the scan tool Liftgate Latch Pawl Switch parameter is Open
    • If not Open 
    1. Ignition/Vehicle Off. Remove the 3 A fused jumper wire, disconnect the harness connector at the K39 Liftgate Control Module, Ignition On/Vehicle in Service Mode.
    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.
      • Go to next step: 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 K39 Liftgate Control Module.
    • Go to next step: If Open 
  11. Verify the scan tool Liftgate Latch Ratchet Switch parameter is Closed.
    • If not Closed 
    1. Ignition/Vehicle Off. Disconnect the harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between the signal circuit terminal 2 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K39 Liftgate Control Module.
    • Go to next step: If Closed 
  12. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 6.
  13. Verify the scan tool Liftgate Latch Ratchet Switch parameter is Open
    • If not Open 
    1. Ignition/Vehicle Off. Remove the 3 A fused jumper wire, disconnect the harness connector at the K39 Liftgate Control Module, Ignition On/Vehicle in Service Mode.
    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.
      • Go to next step: 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 K39 Liftgate Control Module.
    • Go to next step: If Open 
  14. Test or replace the A23C Liftgate Latch Assembly.
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