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Home >> Cadillac >> 2007 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 807 (Power Door Lock System And Release Systems) >> Diagnostic Information and Procedures >> Power Door Locks Inoperative >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

Door Lock Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the applicable door lock switch.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the B+ circuit terminal A for a short to ground.
  3. Verify the scan tool Lock Switch and Unlock Switch parameters are OFF.
    • If not the specified value, test the appropriate signal circuit terminal for a short to voltage. If the circuit tests normal, replace the BCM.
  4. Install a 3-amp fused jumper wire between the signal circuit terminal B and the B+ circuit terminal A. Verify the scan tool Lock Switch parameter is ON.
    • If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal C and the B+ circuit terminal A. Verify the scan tool Unlock Switch parameter is ON.
    • If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  6. If all circuits test normal, test or replace the applicable door lock switch.

Driver Door Unlock Relay Malfunction

  1. Ignition OFF, disconnect the DRV DR UNLCK relay.
  2. Ignition OFF, test for less than 1 ohm of resistance between the switch side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Ignition OFF, test for less than 1 ohm of resistance between the coil side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp does not illuminates between the switch side control circuit terminal and ground.
    • If the test lamp illuminates, test the control circuit for a short to voltage.
  5. Verify that a test lamp illuminates between the switch side B+ circuit terminal and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Connect a test lamp between the coil control circuit terminal and the coil side ground circuit terminal.
  7. Command the Driver Door Unlock ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  8. Install the DRV DR UNLCK relay.
  9. Disconnect the harness connector at the driver door latch.
  10. Ignition OFF, test for less than 5 ohm of resistance between the ground circuit terminal 3 and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, test or replace the DR LCK relay.
  11. Connect a test lamp between the control circuit terminal 2 and the ground circuit terminal 3.
  12. Command the Driver Door Unlock ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the DRV DR UNLCK relay.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the DRV DR UNLCK relay.
  13. If all circuits test normal, test or replace the driver door latch.

Passenger Door Unlock Relay Malfunction

  1. Ignition OFF, disconnect the PASS DR UNLOCK relay.
  2. Ignition OFF, test for less than 1 ohm of resistance between the switch side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Ignition OFF, test for less than 1 ohm of resistance between the coil side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp does not illuminates between the switch side control circuit terminal and ground.
    • If the test lamp illuminates, test the control circuit for a short to voltage.
  5. Verify that a test lamp illuminates between the switch side B+ circuit terminal and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Connect a test lamp between the coil control circuit terminal and the coil side ground circuit terminal.
  7. Command the Passenger Door Unlock ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  8. Install the PASS DR UNLOCK relay.
  9. Disconnect the harness connector at the applicable door latch.
  10. Ignition OFF, test for less than 5 ohm of resistance between the ground circuit terminal 3 and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, test or replace the DR LCK relay.
  11. Connect a test lamp between the control circuit terminal 2 and the ground circuit terminal 3.
  12. Command the Passenger Door Unlock ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the PASS DR UNLOCK relay.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the PASS DR UNLOCK relay.
  13. If all circuits test normal, test or replace the applicable door latch.

Door Lock Relay Malfunction

  1. Ignition OFF, disconnect the DR LCK relay.
  2. Ignition OFF, test for less than 1 ohm of resistance between the switch side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  3. Ignition OFF, test for less than 1 ohm of resistance between the coil side ground circuit terminal and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp does not illuminates between the switch side control circuit terminal and ground.
    • If the test lamp illuminates, test the control circuit for a short to voltage.
  5. Verify that a test lamp illuminates between the switch side B+ circuit terminal and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Connect a test lamp between the coil control circuit terminal and the coil side ground circuit terminal.
  7. Press and release the door lock switch. The test lamp should turn ON and OFF when pressing and releasing the switch.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
  8. Install the DR LCK relay.
  9. Disconnect the harness connector at the applicable door latch.
  10. Ignition OFF, test for less than 5 ohm of resistance between the ground circuit terminal 2 and ground.
    • If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, test or replace the applicable lock relay.
  11. Connect a test lamp between the control circuit terminal 3 and the ground circuit terminal 2.
  12. Press and release the door lock switch. The test lamp should turn ON and OFF when pressing and releasing the switch.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the DR LCK relay.
    • If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the DR LCK relay.
  13. If all circuits test normal, test or replace the applicable door latch.
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