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 the diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) provides battery positive voltage and ground to the appropriate lock and unlock control circuits of the door lock and unlock relays. The lock control circuits of the driver and passenger door latch assemblies share a common relay; however, the unlock control circuits have separate relays. The system is designed this way so that the keyless entry transmitter may be used to unlock only the driver door.
The BCM supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the BCM detects the voltage drop on the signal circuit.
The BCM, upon receipt of a lock switch lock signal, will switch the all lock relay control circuit to battery positive voltage. This will energize the lock relay. The relay will supply voltage to the door lock actuator lock control circuits to one side of the lock actuator. Since the opposing side of the lock actuators are connected to ground through the other lock actuator control circuit and the normally closed contacts of the lock or unlock relay, the doors will then lock appropriately. The remaining unlock relays receive voltage from the I/P fuse block, the BCM upon receipt of a unlock signal or driver door unlock signal will switch the appropriate unlock relay to ground. This will energize the appropriate unlock relay. The relay will supply voltage to the appropriate door unlock control circuits to one side of the appropriate lock actuator. Since the opposing side of the lock actuators are connected to ground through the other lock actuator control circuits and the normally closed contact of the lock relay, the doors will then unlock appropriately.
Reference Information
Schematic Reference
Door Lock/Indicator Schematics Door Lock/Indicator Schematics
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (MN5)
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. Ignition ON, observe the scan tool Driver Door Lock Sw. and Driver Door Unlock Sw. parameters while using the door lock switch-driver. The reading should be Inactive and change to Active when pushing the appropriate switch.
• If the value does not change, refer to Door Lock Switch Malfunction.
2. Command the door latches to LOCK and UNLOCK by using the door lock switch-driver, all doors should LOCK and UNLOCK when changing between the commanded states.
• If a door latch 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
Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S13D door lock switch-driver.
2. Test for less than 1 ohms between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Driver Door Lock Sw. parameter is Inactive.
• If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K9 body control module.
4. Install a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool scan tool Driver Door Lock Sw. parameter is Active.
• 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 body control module.
5. Verify the scan tool Driver Door Unlock Sw. parameter is Inactive.
• If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K9 body control module.
6. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Driver Door Unlock Sw. parameter is Active.
• 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 body control module.
7. If all circuits test normal, test or replace the S13D door lock switch-driver.
Door Lock Malfunction
1. Ignition 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 5 and terminal 6
* A23LR door latch assembly-left rear terminal 2 and terminal 3
* A23RR door latch assembly-right rear terminal 5 and terminal 6
3. Ignition ON, command the door to LOCK and UNLOCK by using the S13D door lock switch-driver. 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 a short to ground or 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. Ignition OFF, disconnect the X2 harness connector at the X51A fuse block-instrument panel.
2. Test for less than 1 ohms between the ground circuit terminal 52 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal 11 and ground.
4. Ignition ON, command the doors to LOCK with a scan tool. The test lamp should illuminate during the LOCK command.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 body control module
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 body control module
5. Connect a test lamp between the control circuit terminal 10 and B+.
6. Command the doors to UNLOCK with a scan tool. The test lamp should illuminate during the UNLOCK command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 body control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the K9 body control module
7. Connect a test lamp between the control circuit terminal 12 and B+.
8. Command the driver door to UNLOCK with a scan tool. The test lamp should illuminate during the UNLOCK command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 body control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the K9 body control module.
9. Test for infinite resistance between the control circuit terminal listed below and ground:
* X2 terminal 2
* X2 terminal 3
* X2 terminal 4
• 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.
10. Test for less than 10ohms between the control circuit terminals listed below:
* X2 terminal 2 and terminal 3
* X2 terminal 2 and terminal 4
* X2 terminal 3 and terminal 4
• If greater than the specified range, test the appropriate control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the appropriate A23 door latch assembly.
11. If all circuits test normal, replace the X51A fuse block-instrument panel.
Component Testing
Door Lock Switch
1. Ignition OFF, disconnect the harness connector at the S13D door lock switch-driver.
2. Test for infinite resistance between the signal terminal 2 and the ground terminal 3 with the switch in the open position.
• If not the specified value, replace the S13D door lock switch-driver.
3. Test for infinite resistance between the signal terminal 4 and the ground terminal 3 with the switch in the open position
• If not the specified value, replace the S13D door lock switch-driver.
4. Test for less than 2 ohms between the signal terminal 4 and the ground terminal 3 with the switch in the LOCK position.
• If greater than the specified range, replace the S13D door lock switch-driver.
5. Test for less than 2 ohms between the signal terminal 2 and the ground terminal 3 with the switch in the UNLOCK position.
• If greater than the specified range, replace the S13D door lock switch-driver.
Door Latch Assembly
1. Ignition OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Install a 15 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.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Instrument Panel Wiring Harness Junction Block Replacement Instrument Panel Wiring Harness Junction Block Replacement
* Door Lock Switch Replacement Service and Repair
* Front Side Door Latch Replacement Service and Repair
* Rear Side Door Latch Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, programming and setup