B3125
Power Door Lock Malfunction - DTC B3125, B3130, or B3135
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.
DTC Descriptors
DTC B3125 01
- Driver Door Only Unlock Circuit Short to Battery
DTC B3125 02
- Driver Door Only Unlock Circuit Short to Ground
DTC B3130 01
- All Doors Unlock Circuit Short to Battery
DTC B3130 02
- All Doors Unlock Circuit Short to Ground
DTC B3135 01
- All Doors Lock Circuit Short to Battery
DTC B3135 02
- All Doors Lock Circuit Short to Ground
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 at ground potential within 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.
Conditions for Running the DTC
When the ignition is ON.
Conditions for Setting the DTC
B3125 01, B3130 01, B3135 01
The BCM detects a short to battery on a door latch control circuit
B3125 02, B3130 02 and B3135 02
* A short to ground or an open/high resistance in the BCM B+ circuit.
* The BCM detects a short to ground on a door latch control circuit.
Action Taken When the DTC Sets
All the power door locks will be inoperative.
Conditions for Clearing the DTC
* This DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
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 Connector End Views By Name
Description and Operation
Power Door Locks Description and Operation Description and Operation
Electrical Information Reference
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Circuit Testing Circuit Testing
* Wiring Repairs Wiring Repairs
* Connector Repairs Connector Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the scan tool BCM Central Door Lock Switch on Console parameter changes from Inactive to Lock and Unlock when cycling the door lock switch between LOCK and UNLOCK.
• If the parameter does not change
Refer to Power Door Lock Switch Malfunction - DTC B3140, B3145, B3150, or B3155 B3140
• If the parameter changes
3. Verify all vehicle doors LOCK and UNLOCK when commanding the doors to LOCK and 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
Driver Door Lock Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A23D door latch assembly-driver. It may take up to 2 minutes for all vehicle systems to power down.
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.
2. Test for greater than 7 V between the control circuit terminal 3 and ground.
• If less than 7 V
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 ohm in the control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance on the circuit.
• If less than 2 ohm, 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.
3. Test for greater than 7 V between the control circuit terminal 2 and ground.
• If less than 7 V
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 ohm in the control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance on the circuit.
• If less than 2 ohm, replace the K9 body control module.
• If greater than 7 V
4. Test or replace the A23 door latch assembly.
Passenger Door Lock Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate A23 door latch assembly. It may take up to 2 minutes for all vehicle systems to power down.
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.
2. Test for greater than 7 V between the control circuit terminal 3 and ground.
• If less than 7 V
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 ohm in the control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance on the circuit.
• If less than 2 ohm, 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.
3. Test for greater than 7 V between the control circuit terminal 2 and ground.
• If less than 7 V
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 ohm in the control circuit end to end.
• If 2 ohm or greater, repair the open/high resistance on the circuit.
• If less than 2 ohm, replace the K9 body control module.
• If greater than 7 V
4. Test or replace the A23D door latch assembly-driver.
All Door Locks Inoperative
1. Ignition OFF and all vehicle systems 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, test the B+ circuit for an open/high resistance.
• If the test lamp does not illuminate and the circuit fuse is open, test the B+ circuit for a short to ground. If the circuit tests normal, disconnect each of the A23 door latch assemblies and test each control circuit for a short to ground.
• 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 listed below and ground:
* Control circuit terminal 1
* Control circuit terminal 2
* Control circuit terminal 4
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
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 Lock Replacement Front Side Door Lock Replacement
* Rear Side Door Lock Replacement Rear Side Door Lock Replacement
* Control Module References Control Module References for BCM replacement, programming and setup