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) 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 12 V. When the central door lock switch is pressed to the lock or unlock position, a signal will be sent to the K9 BCM requesting a lock or unlock command.
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
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify door latches LOCK and UNLOCK when pushing the appropriate switch on the passenger door switch.
• If the door latches do not LOCK or UNLOCK
Refer to Circuit/System Testing - Passenger Door Lock Switch Malfunction.
• If the door latches LOCK or UNLOCK
3. 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 driver door lock switch.
• If the value is always Inactive
Refer to Circuit/System Testing - Driver Door Lock Switch Malfunction.
• If the value changes from Inactive to Lock only
Refer to Circuit/System Testing - Driver Door Lock Switch Malfunction.
• If the value changes from Inactive to Unlock only
Refer to Circuit/System Testing - Driver Door Lock Switch Malfunction.
• If the value is always Lock or Unlock
Refer to Circuit/System Testing - Lock and Unlock Circuit Test.
• If the parameter changes
4. 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 value is always Inactive
Refer to Circuit/System Testing - Central Door Lock Switch Malfunction.
• If the value changes from Inactive to Lock only
Refer to Circuit/System Testing - Central Door Lock Switch Malfunction.
• If the value changes from Inactive to Unlock only
Refer to Circuit/System Testing - Central Door Lock Switch Malfunction.
• If the value is always Lock or Unlock
Refer to Circuit/System Testing - Lock and Unlock Circuit Test.
• If the parameter changes
5. Verify both 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 only the 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 - Both Door Locks Inoperative.
• If the LOCK and UNLOCK function for all doors works
6. All OK.
Circuit/System Testing
Passenger Door Lock Switch Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S13P door lock switch-passenger. 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 4 and ground.
• If 10 ohms or greater
1. Ignition 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. Ignition ON.
4. Test for greater than 10 V between the signal circuit terminal 2 and ground.
• If 10 V or less
1. Ignition 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 3 and ground.
• If 10 V or less
1. Ignition 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 S13P door lock switch-passenger.
Driver Door Lock Switch Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S13D door lock switch-driver. 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 4 and ground.
• If 10 ohms or greater
1. Ignition 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. Ignition ON.
4. Test for greater than 10 V between the signal circuit terminal 2 and ground.
• If 10 V or less
1. Ignition 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 3 and ground.
• If 10 V or less
1. Ignition 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 S13D door lock switch-driver.
Central Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the A20 radio/HVAC controls. Ignition ON.
2. Test for greater than 10 V between the signal circuit terminal 12 and ground.
• If 10 V or less
1. Ignition 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
3. Test for greater than 10 V between the signal circuit terminal 13 and ground.
• If 10 V or less
1. Ignition 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
4. Test or replace the A20 radio/HVAC controls.
Lock and Unlock Circuit Test
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A20 radio/HVAC controls.
2. Disconnect the harness connector at the S13D door lock switch-driver. Ignition ON
3. Verify the scan tool Central Door Lock Switch on Console parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit terminal 15 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
3. Test for infinite resistance between the signal circuit terminal 19 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 body control module.
• If Inactive
4. Connect the harness connector at the S13D door lock switch-driver.
5. 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 S13D door lock switch-driver.
• If the value is always Lock or Unlock
Test or replace the S13D door lock switch-driver.
• If the value changes from Inactive to Lock and Unlock
6. Connect the harness connector at the A20 radio/HVAC controls.
7. 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 value is always Lock or Unlock
Test or replace the A20 radio/HVAC controls.
• If the value changes from Inactive to Lock and Unlock
8. All OK.
Driver Door Lock Malfunction
1. Ignition 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. Ignition ON.
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. Ignition 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. Ignition 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. Ignition OFF, verify the harness connector is firmly seated and secure for the A23P door latch assembly-passenger.
• If the harness connector not seated or secure
Firmly seat and secure the harness connector at the A23P door latch assembly-passenger.
• If the harness connector is firmly seated and secure
2. Disconnect the harness connector at the A23P door latch assembly-passenger. Ignition ON.
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:
* A23P door latch assembly-passenger - control terminal 7
* A23P door latch assembly-passenger - control terminal 8
• If 7 V or less
1. Ignition 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 A23P door latch assembly-passenger.
Both Door Locks Inoperative
1. Ignition OFF, disconnect the X2 harness connector at the K9 body control module, ignition ON.
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. Ignition 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. Ignition 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. Ignition OFF, connect the X2 harness connector at the K9 body control module. Disconnect the harness connector at the A23D door latch assembly-driver, ignition ON.
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. Ignition OFF, disconnect the X6 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit terminal listed below and ground:
* Control circuit terminal 1 X6
* Control circuit terminal 2 X6
* Control circuit terminal 4 X6
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 body control module.
• If greater than 7 V
5. Replace the K9 body control module.
Component Testing
1. Ignition 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
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Front Side Door Latch Replacement Service and Repair
* Door Lock Switch Replacement - Driver Side Door Lock Switch Replacement - Driver Side
* Door Lock Switch Replacement - Passenger Front Door Lock Switch Replacement - Passenger Front
* Control Module References Control Module References for BCM and radio/HVAC control replacement, programming and setup