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Circuit/System Testing

  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, connect the X2 harness connector at the K39 Liftgate Control Module
  4. Disconnect the harness connector at the M17 Liftgate Motor Assembly. Ignition ON/Vehicle in Service Mode
  5. Connect a test lamp between the control circuit terminal 1 and control circuit terminal 4, ignition ON.
  6. Verify the test lamp turns ON and OFF when 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 
  7. Replace the M17 Liftgate Motor Assembly.
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