Circuit/System Testing

Liftgate Unlatch Switch Malfunction

1. Ignition 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 ground circuit terminal 4 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. Ignition ON.
4. Verify the scan tool Door Lock Switch parameter is Inactive.
   • If not Inactive 
   1. Ignition OFF, disconnect the harness connector at the K9 body 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.
   3. 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 K9 Body Control Module.
   • If Inactive 
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 4.
6. Verify the scan tool Door Lock Switch parameter is Unlock.
   • If not Unlock 
   1. Ignition OFF, remove the 3 A fused jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
   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.
      • 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 K9 Body Control Module.
   • If Unlock 
7. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 4.
8. Verify the scan tool Door Lock Switch parameter is Lock.
   • If not Lock 
   1. Ignition OFF, remove the 3 A fused jumper wire, disconnect the harness connector at the K9 body control module, ignition ON.
   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.
      • 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 K9 Body Control Module.
   • If Lock 
9. Test or replace the S46B Liftgate Unlatch Switch.

Liftgate Lock Actuator Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
2. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
   • If the test lamp does not illuminate and the circuit fuse is good 
   1. Ignition 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 
   3. Ignition OFF.
   4. 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
   5. Disconnect the harness connector the M14B Door Lock Actuator-Liftgate.
   6. 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, test or replace the M14B Door Lock Actuator-Liftgate.
   • If the test lamp illuminates 
3. Ignition OFF, connect the X2 harness connector at the K9 Body Control Module and disconnect the harness connector at the M14B Door Lock Actuator-Liftgate. Ignition ON
NOTE:

Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 Body Control Module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the M14B Door Lock Actuator-Liftgate by using the S46B Liftgate Unlatch Switch to restore the voltage for testing.

4. Test for greater than 7 V between the control circuit terminal 1 and ground.
   • If 7 V or less 
   1. Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module.
   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 on the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
   • If greater than 7 V 
NOTE:

Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 body control module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the liftgate latch by using the Liftgate Unlatch Switch to restore the voltage for testing.

5. Test for greater than 7 V between the control circuit terminal 2 and ground.
   • If 7 V or less 
   1. Ignition OFF, disconnect the X6 harness connector at the K9 Body Control Module.
   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 on the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
   • If greater than 7 V 
6. Test or replace the M14B Door Lock Actuator-Liftgate.