Power Door Locks Malfunction
Power Door Locks Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The BCM monitors the voltage level of the door lock and door unlock signal circuits. When the central door lock switch is in the open position, the voltage level in the signal circuit will be near 0 V. When the central door lock switch is pressed to the lock or unlock position, a signal will be sent to the BCM requesting a lock or unlock command.
The BCM, upon receipt of a lock switch lock or unlock signal, will supply battery voltage to the door lock actuator lock or unlock control circuits. Since the opposite side of the lock actuator is connected to ground through the other lock actuator control circuit, the doors will then lock or unlock as commanded.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics Door Lock/Indicator Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Power Door Locks Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
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 control.
• 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.
Circuit/System Testing
Central Door Lock Switch Malfunction
1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC control.
2. Test for less than 10 ohm 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 Center 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 Center 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 Center 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, test or replace the A20 radio/HVAC control.
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 during 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-underhood.
5. Test for infinite resistance between the control circuit listed below and ground:
* Connector X1, terminal 11 at the X50A fuse block-underhood
* Connector X1, terminal 12 at the X50A fuse block-underhood
* 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-underhood.
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-underhood.
8. If all circuits test normal, replace the K9 BCM.
Component Testing
Door Latch
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 A23 door latch assembly 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 control.
2. 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 A20 radio/HVAC control.
3. 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 control.
4. Test for less than 2 ohm 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 control.
5. Test for less than 2 ohm 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 control.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Front Side Door Lock Replacement Front Side Door Lock Replacement
* Rear Side Door Lock Replacement Rear Side Door Lock Replacement
* Fuse Block Replacement Fuse Block Replacement
* Radio Control Assembly Replacement Radio Control Assembly Replacement
* Control Module References Programming and Relearning for BCM replacement, programming and setup