Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

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 body control module (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.

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Power Door Systems 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 LF Door Lock Switch parameters while using the driver door lock switch. The parameter should change from Idle to Lock and Unlock.

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

2. Command the Driver Door Unlock and Lock All Doors with a scan tool. The driver door should perform the UNLOCK and LOCK functions.

⇒	If the driver door does not UNLOCK or LOCK, refer to Driver Door Lock Malfunction.

Driver Door Lock Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the driver door lock switch.
2. Test for less than 1.0 ohm 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 LF Door Lock Switch parameter is Idle.

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

•	Terminal D

•	Terminal E

4. Install a 3A fused jumper wire between the signal circuit terminal E and ground. Verify the scan tool LF Door Lock Switch parameter is Unlock.

⇒	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.

5. Install a 3A fused jumper wire between the signal circuit terminal D and ground. Verify the scan tool LF Door Lock Switch parameter is Lock.

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

Driver Door Lock Malfunction

1. Ignition OFF, disconnect the harness connector at the driver door latch assembly.
2. Test for less than 1.0 ohm 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. Test for less than 1.0 ohm 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 the control circuit terminal B and control circuit terminal A.
5. Ignition ON, command the driver door latch assembly to LOCK and UNLOCK by using the driver door lock switch. The test lamp should illuminate 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 driver door latch assembly.

Door Lock Switch

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

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

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

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

4. Test for less than 2.0 ohms between the signal terminal E and the ground terminal C with the switch in the Unlock position.

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

5. Test for less than 2.0 ohms between the signal terminal D and the ground terminal C with the switch in the Lock position.

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

Driver Door Latch

1. Ignition OFF, disconnect the harness connector at the driver door latch assembly.
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 driver door latch assembly should perform the LOCK/UNLOCK functions.

⇒	If it does not perform as specified, replace the driver door latch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.