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Circuit/System Testing

Interior Liftgate Switch Inoperative

  1. Ignition/Vehicle 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/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 the scan tool Liftgate Front Control Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition/Vehicle Off. Disconnect the harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between the signal circuit terminal 4 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 Inactive 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the ground circuit terminal 2.
  6. Verify the scan tool Liftgate Front Control Switch parameter is Active.
    • If not Active 
    1. Ignition/Vehicle Off. Remove the 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 Active 
  7. Test or replace the S58B Rear Compartment Lid Unlatch Switch-Interior.

Liftgate Unlatch Switch Malfunction

  1. Ignition/Vehicle Off and all vehicle systems Off. Disconnect the harness connector at the S46B Liftgate 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 low reference circuit terminal 1 and ground.
    • If 10 Ω or greater 
    1. Ignition/Vehicle Off. 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, repair the open/high resistance in the low reference connection.
    • Go to next step: If less than 10 Ω 
  3. Ignition On/Vehicle in Service Mode.
  4. Verify the scan tool Liftgate Handle Switch parameter is Inactive.
    • If not Inactive 
    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 Inactive 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1.
  6. Verify the scan tool Liftgate Handle Switch parameter is Active.
    • If not Active 
    1. Ignition/Vehicle Off. 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 Active 
  7. Test or replace the S46B Liftgate Unlatch Switch.

Rear Compartment Latch Switches Malfunction

  1. Ignition/Vehicle Off and all vehicle systems Off. Disconnect the harness connector at the A23C Liftgate Latch Assembly. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 6 and ground.
    • If 10 Ω or greater 
    1. Ignition/Vehicle Off. 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 
  3. Ignition On/Vehicle in Service Mode.
  4. Verify the scan tool Liftgate Latch Pawl Switch parameter is Closed.
    • If not Closed 
    1. Ignition/Vehicle Off. Disconnect the X1 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 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 6.
  6. 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 X1 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 terminal 3 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 
  7. Verify the scan tool Liftgate Latch Ratchet Switch parameter is Closed.
    • If not Closed 
    1. Ignition/Vehicle Off. Disconnect the X1 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 
  8. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 6.
  9. 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 X1 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 terminal 2 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 
  10. Test or replace the A23C Liftgate Latch Assembly.

Liftgate Latch Release Malfunction

  1. Ignition/Vehicle OFF, disconnect the X2 harness connector at the K39 Liftgate Control Module.
  2. Test for less than 1 V between the control circuit terminals listed below and ground:
    • Control circuit terminal 1 X2
    • Control circuit terminal 2 X2
    • If 1 V or greater 
    1. Ignition/Vehicle OFF, disconnect the harness connector at the A23C Liftgate Latch Assembly. ignition ON/Vehicle in Service Mode.
    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.
    • Go to next step: If less than 1 V 
  3. Test for infinite resistance between the control circuit terminals listed below and ground:
    • Control circuit terminal 1 X2
    • Control circuit terminal 2 X2
    • If less than infinite resistance 
    1. Ignition OFF, disconnect the harness connector at the A23C Liftgate Latch Assembly.
    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, replace the A23C Liftgate Latch Assembly.
    • Go to next step: If infinite resistance 
  4. Test for less than 10 Ω between the control circuit terminal 1 and the control circuit terminal 2.
    • If 10 Ω or greater 
    1. Ignition/Vehicle OFF, disconnect the harness connector at the A23C Liftgate Latch Assembly.
    2. Test for less than 2 Ω between the K39 Liftgate Control Module control circuit terminal 1 and the A23C Liftgate Latch Assembly control circuit terminal 4.
      • If 2 Ω or greater, repair the open/high resistance on the circuit.
    3. Test for less than 2 Ω between the K39 Liftgate Control Module control circuit terminal 2 and the A23C Liftgate Latch Assembly control circuit terminal 1.
      • If 2 Ω or greater, repair the open/high resistance on the circuit.
      • If less than 2 Ω, replace the A23C Liftgate Latch Assembly.
    • Go to next step: If less than 10 Ω 
  5. Replace the K39 Liftgate Control Module.

Power Trunk Lid Inoperative

  1. Ignition/Vehicle OFF, disconnect the X2 harness connector at the K39 Liftgate Control Module, Ignition On/Vehicle in Service Mode.
  2. 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.
      • Go to next step: If infinite resistance
    3. Disconnect the harness connector at the M17 Liftgate Motor Assembly.
    4. Test for infinite resistance between each control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M17 Liftgate Motor Assembly.
    • Go to next step: If the test lamp illuminates 
  3. Ignition/Vehicle Off and all vehicle systems Off. Connect the X2 harness connector at the K39 Liftgate Control Module. It may take up to 2 minutes for all vehicle systems to power down.
  4. Disconnect the harness connector at the M17 Liftgate Motor Assembly.
  5. Test for less than 10 Ω between the low reference circuit terminal 3 and ground.
    • If 10 Ω or greater 
    1. Ignition/Vehicle Off.
    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 
  6. Ignition ON/Vehicle in Service Mode, test for greater than 11 V between the 12 V reference circuit terminal 2 and ground.
    • If 11 V or less 
    1. Ignition OFF, disconnect the X3 harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between the 12 V reference circuit 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 12 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 K39 Liftgate Control Module.
    • Go to next step: If greater than 11 V 
  7. Test for greater than 11 V between the Position Sensor Signal 1 circuit terminal 7 and ground.
    • If 11 V or less 
    1. Ignition/Vehicle Off. Disconnect the X3 harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between the Position Sensor Signal 1 circuit 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 Position Sensor Signal 1 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 greater than 11 V 
  8. Test for greater than 11 V between the Position Sensor Signal 2 circuit terminal 8 and ground.
    • If 11 V or less 
    1. Ignition/Vehicle Off. Disconnect the X3 harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between the Position Sensor Signal 2 circuit 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 Position Sensor Signal 2 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 greater than 11 V 
  9. Connect a test lamp between the control circuit terminal 1 and control circuit terminal 4. Ignition On/Vehicle in Service Mode.
  10. Verify the test lamp turns ON and OFF while pressing the B70 Liftgate Close Switch.
    • If the test lamp remains OFF 
    1. Ignition/Vehicle Off. Remove the test lamp, disconnect the X3 harness connector at the K39 Liftgate Control Module.
    2. Test for infinite resistance between each control circuit 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 control circuits 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.
    • If the test lamp is always ON 
    1. Ignition/Vehicle Off. Remove the test lamp, disconnect the X3 harness connector at the K39 Liftgate Control Module. Ignition On/Vehicle in Service Mode.
    2. Test for less than 1 V between each control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K39 Liftgate Control Module
    • Go to next step: If the test lamp turns ON and Off 
  11. Replace the M17 Liftgate Motor Assembly.

Liftgate Close Switch Malfunction

  1. Ignition/Vehicle Off and all vehicle systems Off. Disconnect the harness connector at the B70 Liftgate Close Switch. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 4 and ground.
    • If 10 Ω or greater 
    1. Ignition/Vehicle Off. 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, repair the open/high resistance in the low reference connection.
    • Go to next step: If less than 10 Ω 
  3. Ignition On/Vehicle in Service Mode.
  4. Verify the scan tool Liftgate Rear Close Switch parameter is Inactive.
    • If not Inactive 
    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 Inactive 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 4.
  6. Verify the scan tool Liftgate Rear Close Switch parameter is Active.
    • If not Active 
    1. Ignition/Vehicle Off. 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 Active 
  7. Test or replace the B70 Liftgate Close Switch.
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