Volt

Power Door Locks Malfunction

The body control module (BCM) powers the reversible door latch assemblies by providing battery positive voltage and ground to the appropriate lock and unlock control circuits of the door latch assemblies. The lock and unlock control circuits of the rear doors and passenger door latch assemblies are all connected together. When the door latch assemblies are not active, all actuator lock and unlock control circuits are at ground potential within the BCM. Transitioning of the lock actuators to the lock or unlocked position depends upon which control circuits receive voltage and which control circuits receive ground.

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. Vehicle in Service Mode, observe the scan tool BCM Central Door Lock Switch on Console parameter. The reading should be Inactive and change to Lock and Unlock when pushing the appropriate switch on the A20 radio/HVAC controls.

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

2. Command the doors to LOCK and UNLOCK with a scan tool, all doors should LOCK and UNLOCK while changing between the commanded states.

⇒	If a door does not LOCK or UNLOCK, refer to Door Lock Malfunction.

⇒	If all doors do not LOCK or UNLOCK, refer to All Door Locks inoperative.

Central Door Lock Switch Malfunction

1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC controls.
2. Test for less than 10 Ω between the ground circuit terminal 17 and ground.

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

3. Vehicle in Service Mode, verify the scan tool Central Door Lock Switch on Centre Console parameter is Inactive.

⇒	If the value is Lock , test the signal circuit terminal 12 for a short to ground. If the circuit tests normal, replace the K9 BCM.

⇒	If the value is Unlock , test the signal circuit terminal 13 for a short to ground. If the circuit tests normal, replace the K9 BCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 12 and ground. Verify the scan tool Central Door Lock Switch on Centre Console 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 K9 BCM.

5. Install a 3 A fused jumper wire between the signal circuit terminal 13 and ground. Verify the scan tool Central Door Lock Switch on Centre Console 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 K9 BCM.

6. If all circuits test normal, replace the A20 radio/HVAC controls.

Door Lock Malfunction

1. Vehicle OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Connect a test lamp between the control circuit terminals listed below:

•	A23D door latch assembly-driver terminal 2 and terminal 3

•	A23P door latch assembly-passenger terminal 7 and terminal 8

•	A23LR door latch assembly-left rear terminal 2 and terminal 3

•	A23RR door latch assembly-right rear terminal 7 and terminal 8

3. Vehicle in Service Mode, command the door to LOCK and UNLOCK by using the central door lock switch. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.

⇒	If the test lamp is always OFF for either the LOCK or UNLOCK command, test the control circuit for an open/high resistance between the connector and the circuit splice.

4. If all circuits test normal, test or replace the A23 door latch assembly.

All Door Locks inoperative

1. Vehicle OFF, disconnect the X2 harness connector at the K9 BCM.
2. Vehicle in Service Mode, verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance

3. Vehicle OFF, disconnect the X6 harness connector at the K9 BCM.
4. Disconnect the X1 harness connector at the X50A fuse block-under-bonnet.
5. Test for infinite resistance between the control circuit listed below and ground:

•	Connector X1, terminal 11 at the X50A fuse block-under-bonnet

•	Connector X1, terminal 12 at the X50A fuse block-under-bonnet

•	Connector X6 terminal 1 at the K9 BCM

•	Connector X6 terminal 4 at the K9 BCM

⇒	If not the specified value, test the appropriate control circuit for a short to ground. If the circuit tests normal, test or replace the appropriate A23 door latch assembly.

6. Connect the X1 harness connector at the X50A fuse block-under-bonnet.
7. Test for infinite resistance between the control circuit terminal 2 X6 at the K9 BCM and ground.

⇒	If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the X50A fuse block-under-bonnet.

8. If all circuits test normal, replace the K9 BCM.

Door Catch

1. Vehicle OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Install a 25 A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the door latch should perform the LOCK and UNLOCK functions.

⇒	If it does not perform as specified, replace the A23 door latch assembly.

Central Door Lock Switch

1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC controls.
2. Test for infinite resistance between the signal terminal 12 and the ground terminal 17 with the switch in the open position.

⇒	If not the specified value, replace the A20 radio/HVAC controls.

3. Test for infinite resistance between the signal terminal 13 and the ground terminal 17 with the switch in the open position.

⇒	If not the specified value, replace the S48C multifunction switch 1-instrument panel.

4. Test for less than 2 Ω between the signal terminal 12 and the ground terminal 17 with the switch in the lock position.

⇒	If greater than the specified range, replace the A20 radio/HVAC controls.

5. Test for less than 2 Ω between the signal terminal 13 and the ground terminal 17 with the switch in the unlock position.

⇒	If greater than the specified range, replace the A20 radio/HVAC controls.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.