Circuit/System Testing

Liftgate Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate S45A Liftgate Control Switch-Exterior or S45B Liftgate Control Switch-Interior. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 30 Ω between the low reference circuit terminal 2 and ground.
   • If 30 Ω or greater 
   1. Ignition 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.
   • If less than 30 Ω 
3. Ignition ON.
4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
5. Verify the scan tool Liftgate Handle Sw. Status parameter is Active.
   • If not Active 
   1. Ignition OFF, remove the 3 A fused jumper wire, disconnect the harness connector at the K39 Liftgate 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 K39 Liftgate Control Module.
   • If Active 
6. Test or replace the S45A Liftgate Control Switch-Exterior or the S45B Liftgate Control Switch-Interior.

Liftgate Signal Circuit Test

1. Ignition OFF, disconnect the harness connector at the S45A Liftgate Control Switch-Exterior and S45B Liftgate Control Switch-Interior. Ignition ON
2. Verify the scan tool Liftgate Handle Sw. Status parameter is Inactive.
   • If not Inactive 
   1. Ignition OFF, disconnect the X1 harness connector at the K39 Liftgate Control Module.
   2. Test for infinite resistance between the K39 Liftgate Control Module signal circuit terminal 14 X1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K39 Liftgate Control Module
   • If Inactive 
3. Connect the harness connector at the S45A Liftgate Control Switch-Exterior.
4. Verify the scan tool Liftgate Handle Sw. Status parameter changes from Inactive to Active when pressing the S45A Liftgate Control Switch-Exterior.
   • If the parameter does not change 

     Test or replace the S45A Liftgate Control Switch-Exterior.

   • If the parameter changes 
5. Connect the harness connector at the S45B Liftgate Control Switch-Interior.
6. Verify the scan tool Liftgate Handle Sw. Status parameter changes from Inactive to Active when pressing the S45B Liftgate Control Switch-Interior.
   • If the parameter does not change 

     Test or replace the S45B Liftgate Control Switch-Interior.

   • If the parameter changes 
7. All OK.