The DR/LCK fuse supplies battery positive voltage to the I/P fuse block for the door lock system. The body control module (BCM) supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the reference voltage is taken directly to ground and the BCM detects the voltage drop on the signal circuit.

The BCM, upon receipt of a door lock switch lock or unlock signal, will switch the appropriate door lock actuator control circuits to battery positive voltage. The opposing side of the door lock actuators are connected to ground internally within the BCM through the other door lock actuator control circuit and the doors will lock or unlock appropriately.

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the scan tool Driver Door Lock Sw, Psgr Door Lock Sw, Driver Door Unlock Sw and Psgr Door Unlock Sw parameters while using the driver and passenger door lock switches. The parameters should change between Active and Inactive.

⇒	If the values does not change between the commanded states, refer to Door Lock Switch Malfunction.

2. Command the driver door and passenger door lock actuators to LOCK and UNLOCK with the scan tool, the doors should LOCK and UNLOCK when changing between commanded states.

⇒	If a door lock actuator does not perform the LOCK and UNLOCK functions, refer to Door Lock Malfunction.

Door Lock Switch Malfunction

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

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

3. Ignition ON, verify the scan tool Door Lock Sw parameter 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. Verify the scan tool Door Unlock Sw parameter 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 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool Door Unlock Sw parameter 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 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool Door Lock Sw parameter 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.

7. If all circuits test normal, test or replace the door lock switch.

Door Lock Malfunction

1. Ignition OFF, disconnect the X1 harness connector at the I/P fuse block.
2. Test for less than 1 ohm between the ground circuit terminal J1 and ground.

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

3. Connect a test lamp between the control circuit terminal K4 and ground.
4. Command the doors to LOCK with a scan tool. The test lamp should briefly illuminate while commanding the LOCK state.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

⇒	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.

5. Connect a test lamp between the control circuit terminal K5 and B+.
6. Command the doors to UNLOCK with a scan tool. The test lamp should briefly illuminate while commanding the UNLOCK state.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.

7. Connect a test lamp between the control circuit terminal K6 and B+.
8. Command the driver door to UNLOCK with a scan tool. The test lamp should briefly illuminate while commanding the UNLOCK state.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.

9. Ignition OFF, connect the X1 harness connector at the I/P fuse block and disconnect the harness connector at the appropriate door lock.
10. Test for less than 1 ohm between the control circuit terminal listed below and ground:

•	Driver door lock terminal 2

•	Driver door lock terminal 3

•	Left rear door lock terminal 2

•	Left rear door lock terminal 3

•	Right rear door lock terminal 5

•	Right rear door lock terminal 6

•	Passenger door lock terminal 5

•	Passenger door lock terminal 6

⇒	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 I/P fuse block.

11. Connect a test lamp between control circuit terminals of the door lock listed below:

•	Driver door lock terminal 2 and terminal 3

•	Left rear door lock terminal 2 and terminal 3

•	Right rear door lock c terminal 5 and terminal 6

•	Passenger door lock terminal 5 and terminal 6

12. Ignition ON, command the door lock 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 on both control circuits. If the circuits test normal, replace the I/P fuse block.

13. If all circuits test normal, test or replace the door lock.

Door Lock Switch

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

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

3. Test for less than 2 ohms between the signal terminal D and the ground terminal B with the switch in the lock position.

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

4. Test for less than 2 ohms between the signal terminal E and the ground terminal B with the switch in the unlock position

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

Door Lock Assembly

1. Ignition OFF, disconnect the harness connector at the appropriate door lock.
2. Install a 15A fused jumper wire between one of the control terminals and 12V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the door lock should perform the LOCK/ UNLOCK functions.

⇒	If it does not perform as specified, replace the door lock.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.