When the body control module (BCM) detects a transition of either of the door lock switches to the lock position, it switches the door lock actuator lock control circuit to voltage. Since the lock actuator unlock control circuits are at ground potential within the BCM, the door lock actuator motors transition to the Lock position. When the BCM detects a transition of either of the door lock switches to the unlock position, it switches the driver door lock actuator unlock control circuit to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the LF door lock actuator motor transitions to the unlock position. The driver door lock actuator unlock control circuit is a dedicated control circuit used only for the driver door lock actuator motor. This is done so that the driver door may be unlocked by itself using a keyless entry transmitter or an automatic door unlock function, if programmed. The passenger doors include the passenger front door, the passenger rear sliding doors, and the liftgate door. When the BCM detects a transition of either of the door lock switches to the unlock position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuator motors transition to the unlock position. The door lock actuator unlock control circuits are dedicated control circuits used only for the passenger door lock actuator motors. This is done so that the driver door may be unlocked separately from the passenger doors using a keyless entry transmitter or an automatic door unlock function, if programmed.

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Vehicle Access Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

Scan Tool Reference

1. Ignition ON, observe the scan tool Door Lock switch parameters while pressing the door lock and door unlock on both door lock switches. The reading should change between LOCK and UNLOCK.

⇒	If the reading does not change, refer to Door Lock Switch Malfunction.

2. Command the Driver Door Unlock ON and OFF with a scan tool. The driver door should unlock.

⇒	If the driver door does not unlock, refer to Front Door/Liftgate Lock Malfunction.

3. Command Unlock All Doors with a scan tool. All doors should unlock.

⇒	If one or both front doors or liftgate do not unlock, refer to Front Door/Liftgate Lock Malfunction.

⇒	If either sliding doors do not unlock, refer to Sliding Door Lock Malfunction.

4. Command Lock All Doors with a scan tool. All of the vehicle doors should lock.

⇒	If one or both front doors or liftgate do not lock, refer to Front Door/Liftgate Lock Malfunction.

⇒	If either sliding doors do not lock, refer to Sliding Door Lock Malfunction.

Door Lock Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Ignition OFF, test for less than 1 ohm for resistance between the ground circuit terminal C and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Lock Switch is Inactive.

⇒	If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.

4. Ignition ON, verify the scan tool Unlock Switch is Inactive.

⇒	If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.

5. Install a 3-amp fused jumper wire between the Lock signal circuit terminal E and ground. Verify the scan tool Door Unlock Switch is Active.

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

6. Install a 3-amp fused jumper wire between the Lock signal circuit terminal D and ground. Verify the scan tool Door Lock Switch is Active.

⇒	If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

Front Door/Liftgate Lock Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
2. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal B and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

3. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal A and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.

4. Connect a test lamp between control circuit terminal B and control circuit terminal A.
5. Ignition ON, command the door latch to LOCK and UNLOCK with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the BCM.

6. If all circuits test normal, test or replace the appropriate door latch assembly.

Sliding Door Lock Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate door contact plate.
2. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal B and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If all circuits test normal, replace the BCM.

3. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal A and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If all circuits test normal, replace the BCM.

4. Connect a test lamp between control circuit terminal B and control circuit terminal A.
5. Ignition ON, command the door latch to LOCK and UNLOCK with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the BCM.

6. Ignition OFF, connect the harness connector at the appropriate door contact plate and close the appropriate sliding door.
7. Ignition OFF, disconnect the harness connector at the appropriate door latch.
8. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal B and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the door contact plate.

9. Ignition OFF, test for less than 1 ohm of resistance between the control circuit terminal A and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the door contact plate.

10. Connect a test lamp between control circuit terminal B and control circuit terminal A.
11. Ignition ON, command the door latch to LOCK and UNLOCK with a scan tool. The test lamp should turn ON when commanding the LOCK and UNLOCK states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the door contact plate.

12. If all circuits test normal, test or replace the appropriate door latch assembly.

Door Lock Switch

1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminal E and the ground circuit terminal C with the switch in the open position.

⇒	If not the specified value, replace the appropriate door lock switch.

3. Test for infinite resistance between the signal terminal D and the ground circuit terminal C with the switch in the open position.

⇒	If not the specified value, replace the appropriate door lock switch.

4. Test for less than 2 ohms between the signal terminal E and the ground circuit terminal C with the switch in the Unlock position.

⇒	If greater than the specified range, replace the appropriate door lock switch.

5. Test for less than 2 ohms between the signal terminal D and the ground circuit terminal C with the switch in the Lock position.

⇒	If greater than the specified range, replace the appropriate door lock switch.

Door/Liftgate Latch

1. Install a 25-amp fused jumper wire between the control terminal A and 12 volts. Momentarily install a jumper wire between the control terminal B and ground. The appropriate door latch should perform the LOCK/UNLOCK function.

⇒	If the function does not perform as specified, replace the appropriate door latch.

2. Reverse the jumper wires; the appropriate door latch should perform the LOCK/UNLOCK function.

⇒	If the function does not perform as specified, replace the appropriate door latch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.