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 DR LCK fuse supplies battery positive voltage to the body control module (BCM) for the door lock system.
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, the reference voltage is taken directly to ground and the BCM detects the voltage drop on the signal circuit. If a door lock switch is placed in the unlock position, the reference voltage is taken to ground through a 1.5k ohm resistor that is internal to the door lock switches and detects approximately 2.9 V on the signal circuit. This is how the BCM determines what portion of the door lock switch was activated.
The BCM, upon receipt of a door lock switch lock or unlock signal, will switch the appropriate door lock actuator control circuits to battery positive voltage. The opposing side of the door lock actuators is connected to ground internally within the BCM through the other door lock actuator control circuit and the doors will lock or unlock appropriately.
Diagnostic Aids
If either panel van access panels are open or ajar, the driver door will immediately UNLOCK following the LOCK command. If both access panels are closed and the scan tool Door Ajar Switch parameter is Door Ajar, refer to Door Ajar Indicator Malfunction Door Ajar Indicator Malfunction
Reference Information
Schematic Reference
Door Lock/Indicator Schematics (Door Lock/Indicator Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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 Door Lock Switch parameter while using each door lock switch. The parameter should change between Idle, Lock and Unlock.
• If the value does not change between commanded states, refer to Door Lock Switch Malfunction
2. Command the Driver Door Unlock, Lock All Doors and Passenger Doors Unlock with the scan tool, the driver and passenger doors should perform the LOCK and UNLOCK command.
• If a door does not LOCK or UNLOCK when changing between the commanded states, refer to Door Lock Malfunction.
• If both door latches are inoperative, refer to Door Latches Inoperative.
Circuit/System Testing
Door Lock Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for less than 1.0 ohm between the ground circuit terminal E and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Door Lock Switch parameter is Idle.
• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Door Lock Switch 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 BCM.
5. If all circuits test normal, test or replace the door lock switch.
Door Lock Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
2. Connect at test lamp between the control circuit terminal 2 and control circuit terminal 3.
3. Ignition ON, command the door latch to LOCK and UNLOCK by using the driver door lock switch. The test lamp should turn ON when commanding the LOCK and UNLOCK states.
• If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the BCM.
• If the test lamp is OFF during the LOCK or UNLOCK command, test either control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the BCM.
4. If all circuits test normal, test or replace door latch.
Door Latches Inoperative
1. Ignition OFF, disconnect the X4 harness connector at the BCM.
2. Test for less than 1.0 ohm between the ground circuit terminal E12 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect the X4 harness connector and disconnect the X3 harness connector at the BCM.
4. Verify that a test lamp does not illuminate between the control circuit terminal B1 and B+.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the driver door latch.
5. Verify that a test lamp does not illuminate between the control circuit terminal A5 and B+.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the appropriate door latch.
6. Verify that a test lamp does not illuminate between the control circuit terminal A1 and B+.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the passenger door latch.
7. If all circuits test normal, replace the BCM.
Component Testing
Door Lock Switch
1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
2. Test for infinite resistance between the signal terminal A and the ground terminal E with the switch in the open position.
• If not the specified value, replace the door lock switch.
3. Test for 1.4k-1.6k ohms between the signal terminal A and the ground terminal E with the switch in the Unlock position.
• If greater or less than the specified range, replace the door lock switch
4. Test for less than 2.0 ohm between the signal terminal A and the ground terminal E with the switch in the Lock position.
• If greater than the specified range, replace the door lock switch.
Door Latch
1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
2. Install a 15A 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 latch should perform the LOCK/UNLOCK functions.
• If it does not perform as specified, replace the door latch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Side Door Lock Replacement (Front Side Door Lock Replacement)
* Door Lock Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)For BCM replacement, setup, and programming