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 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 supplied a floating voltage door driver by 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.
Diagnostic Aids
Verify the smooth and consistent mechanical operation of each part of the door latch system prior to performing extensive electrical diagnostics
Any door that does not function smoothly or consistently, refer to Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function Door Will Not Open/Close, Door Binding, or Locks, Handles, or Cylinders Do Not Function.
Reference Information
Schematic Reference
* Door Lock/Indicator Schematics Door Lock/Indicator Schematics
* Body Control System Schematics [1][2]Body Control Systems
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.
2. Verify the scan tool BCM Central Door Lock Switch on Console parameter changes from Inactive to Lock and Unlock when pushing the appropriate switch on the central door lock switch.
• If the parameter does not change
Refer to Circuit/System Testing - Central Door Lock Switch Malfunction.
• If the parameter changes
3. Verify all vehicle doors LOCK and UNLOCK when commanding the All Doors Lock/Unlock with a scan tool.
• If only the driver door LOCK or UNLOCK functions do not work
Refer to Circuit/System Testing - Driver Door Lock Malfunction.
• If one or more, but not all, passenger door LOCK or UNLOCK functions do not work
Refer to Circuit/System Testing - Passenger Door Lock Malfunction.
• If all door LOCK and UNLOCK functions do not work
Refer to Circuit/System Testing - All Door Lock Inoperative.
• If the LOCK and UNLOCK function for all doors works
4. All OK.
Circuit/System Testing
Central Door Lock Switch Malfunction
1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC control. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 17 and ground.
• If 10 ohms or greater
1. Vehicle OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Vehicle in Service Mode.
4. Test for greater than 10 V between the signal circuit terminal 12 and ground.
• If 10 V or less
1. Vehicle OFF, disconnect the harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 10 V
5. Test for greater than 10 V between the signal circuit terminal 13 and ground.
• If 10 V or less
1. Vehicle OFF, disconnect the harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 10 V
6. Test or replace the A20 radio/HVAC control.
Driver Door Lock Malfunction
1. Vehicle OFF, verify the harness connector is firmly seated and secure for the A23D door latch assembly-driver.
• If the harness connector not seated or secure
Firmly seat and secure the harness connector at the A23D door latch assembly-driver.
• If the harness connector is firmly seated and secure
2. Disconnect the harness connector at the A23D door latch assembly-driver. Vehicle in Service Mode.
Note: Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 body control module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the door locks using the central door lock switch to restore the voltage for testing.
3. Test for greater than 7 V between the control circuit terminal 3 and ground.
• If 7 V or less
1. Vehicle OFF, disconnect the X6 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 7 V
Note: Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 body control module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the door locks using the central door lock switch to restore the voltage for testing.
4. Test for greater than 7 V between the control circuit terminal 2 and ground.
• If 7 V or less
1. Vehicle OFF, disconnect the X6 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 7 V
5. Test or replace the A23D door latch assembly-driver.
Passenger Door Lock Malfunction
1. Vehicle OFF, verify the harness connector is firmly seated and secure for the appropriate passenger or rear A23 door latch assembly.
• If the harness connector not seated or secure
Firmly seat and secure the harness connector at the passenger or rear A23 door latch assembly.
• If the harness connector is firmly seated and secure
2. Disconnect the harness connector at the appropriate passenger or rear A23 door latch assembly. Vehicle in Service Mode.
Note: Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 body control module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the door locks using the central door lock switch to restore the voltage for testing.
3. Test for greater than 7 V between the control circuit terminal listed below and ground:
* Control terminal 7 - A23P door latch assembly-passenger
* Control terminal 8 - A23P door latch assembly-passenger
* Control terminal 7 - A23RR door latch assembly-right rear
* Control terminal 8 - A23RR door latch assembly-right rear
* Control terminal 2 - A23LR door latch assembly-left rear
* Control terminal 3 - A23LR door latch assembly-left rear
• If 7 V or less
1. Vehicle OFF, disconnect the X6 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If greater than 7 V
4. Test or replace the A23 door latch assembly.
All Door Locks Inoperative
1. Vehicle OFF, disconnect the X2 harness connector at the K9 body control module, Vehicle in Service Mode.
2. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Vehicle OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Vehicle OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Disconnect the harness connector at each of the A23 door latch assemblies.
4. Test for infinite resistance between each control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the appropriate A23 door latch assembly.
• If the test lamp illuminates
3. Vehicle OFF, connect the X2 harness connector at the K9 body control module. Disconnect the harness connector at the A23D door latch assembly-driver, Vehicle in Service Mode.
Note: Leaving the DMM connected between a control circuit and ground for greater than 20 seconds will cause the K9 body control module to interpret the test as a system fault and will cause the voltage on the control circuit to drop to 0 V. If the voltage drops to 0 V, operate the door locks using the central door lock switch to restore the voltage for testing.
4. Test for greater than 7 V between the control circuit terminal 2 and ground.
• If 7 V or less
1. Vehicle OFF, disconnect the KR97 door lock relay.
2. Disconnect the X6 harness connector at the K9 body control module.
3. Test for infinite resistance between the control circuit terminal listed below and ground:
* Control circuit terminal 55 - KR97 door lock relay
* Control circuit terminal 12 - KR97 door lock relay
* Control circuit terminal 1 X6 - K9 body control module
* Control circuit terminal 4 X6 - K9 body control module
• If less than infinite resistance, repair the short to ground on the circuit.
1. Vehicle OFF, connect the KR97 door lock relay.
2. Test for infinite resistance between the K9 body control module control circuit terminal 2 X6 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, test or replace the KR97 door lock relay.
• If greater than 7 V
5. Replace the K9 body control module.
Component Testing
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 12 and the ground terminal 17 with the switch in the open position.
• If less than infinite resistance
Replace the A20 radio/HVAC control.
• If infinite resistance
3. Test for infinite resistance between the signal terminal 13 and the ground terminal 17 with the switch in the open position.
• If less than infinite resistance
Replace the A20 radio/HVAC control
• If infinite resistance
4. Test for less than 2 ohms between the signal terminal 12 and the ground terminal 17 with the switch in the Lock position.
• If 2 ohms or greater
Replace the A20 radio/HVAC control.
• If less than 2 ohms
5. Test for less than 2 ohms between the signal terminal 13 and the ground terminal 17 with the switch in the Unlock position.
• If 2 ohms or greater
Replace the A20 radio/HVAC control.
• If less than 2 ohms
6. All OK
Door Latch Test
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 function.
• If the actuator does not perform the LOCK and UNLOCK function
Replace the A23 door latch assembly.
• If the actuator performs the LOCK and UNLOCK function
3. All OK
Relay Test
1. Vehicle OFF, disconnect the KR97 door lock relay.
2. Test for 60-200 ohms between terminals 54 and 58.
• If less than 60 ohms or greater than 200 ohms
Replace the KR97 door lock relay.
• If between 60-200 ohms
3. Test for infinite resistance between the terminals listed below:
* 54 and 56
* 54 and 55
* 58 and 56
* 58 and 55
• If less than infinite resistance
Replace the KR97 door lock relay.
• If infinite resistance
4. Install a 3 A fused jumper wire between relay terminal 54 and 12 V. Install a jumper wire between relay terminal 58 and ground.
5. Test for less than 2 ohms between terminals 46 and 45.
• If 2 ohms or greater
Replace the KR97 door lock relay.
• If less than 2 ohms
6. All OK
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* 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