B3135
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
- Driver Door Only Unlock Circuit
DTC B3130
- All Doors Unlock Circuit
DTC B3135
- All Doors Lock Circuit
For symptom byte information refer to: Symptom Byte List Symptom Byte List
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.
Conditions for Running the DTC
Ignition 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.
B3125 04, B3130 04, B3135 04
The BCM detects an open/high resistance on a door latch control circuit
Action Taken When the DTC Sets
All 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 Outside Rearview Mirror - Driver
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 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
3. All OK.
Circuit/System Testing
Driver Door Lock Malfunction
1. Ignition OFF, 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 driver 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 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 driver 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 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 A23D Door Latch Assembly-Driver.
Passenger Door Lock Malfunction
1. Ignition 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. 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 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 circuit terminal 7
* A23RR Door Latch Assembly-Right Rear - control circuit terminal 7
* A23LR Door Latch Assembly-Left Rear - control circuit terminal 2
• 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 door lock switch to restore the voltage for testing.
4. Test for greater than 7 V between the control circuit terminal listed below and ground:
* A23P Door Latch Assembly-Passenger - control circuit terminal 8
* A23RR Door Latch Assembly-Right Rear - control circuit terminal 8
* A23LR Door Latch Assembly-Left Rear - control circuit terminal 3
• If 7 V or less
1. Ignition OFF, disconnect the X2 harness connector at the X51A Fuse Block-Instrument Panel.
2. Disconnect the X6 harness connector at the K9 Body Control Module.
3. Test for less than 2 ohms between the control circuit terminals listed below:
* X51A Fuse Block-Instrument Panel control circuit terminal 7 X2 and A23P Door Latch Assembly-Passenger control circuit terminal 8
* X51A Fuse Block-Instrument Panel control circuit terminal 10 X2 and K9 Body Control Module control circuit terminal 2 X6
• If greater than 2 ohms, repair the open/high resistance on the circuit.
1. Connect the X2 harness connector at the X51A Fuse Block-Instrument Panel
2. Test for less than 2 ohms between the A23P Door Latch Assembly-Passenger control circuit terminal 8 and the K9 Body Control Module control circuit terminal 2 X6
• If greater than 2 ohms, replace the X51A Fuse Block-Instrument Panel.
1. Connect the X6 harness connector at the K9 Body Control Module
2. Ignition ON, test for greater than 7 V between the A23P Door Latch Assembly-Passenger control circuit terminal 8 and ground
• If 7 V or less, replace the K9 Body Control Module
• If greater than 7 V
5. Test or replace the A23 Door Latch Assembly.
All 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 driver 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 Lock Replacement Front Side Door Lock Replacement
* Rear Side Door Lock Replacement Rear Side Door Lock Replacement
* Fuse Block Replacement Fuse Block Replacement
* Control Module References Control Module References for BCM replacement, programming and setup